Boolean Logical Enunciators for complex searches

It is a good idea to read the tutorials below before attempting any complex combinations of Boolean Enunciators, otherwise frustration might likely be the result of wrong queries at the search engines. If doing the combination correctly, the search engine will give highly relevant documents in response.

Claymont
Boolean tutorial
http://www.claymont.com/search/ixqlang.asp

Cameras in the World Wide Web

A view of the world in real time. A road in Cincinnati or Chicago, a street in New York or Nashville, showing what those who are there at this very instant are also seeing. Only a suggestion for newcomers about this feature: Please do not be a voyeur.

Earth Cam
Cameras in many geographic locations
http://search.earthcam.com/

Cinematography

Originally recorded on chemical film or on magnetic analogue video, and later converted to digital video, or recorded directly as digital, there are available thousands of motion pictures of short as well as of long reel, silent or sounded, in black and white or coloured. A treasure for lovers of the good old films, or for those who prefer images or sounds of more recent release.

British Pathe
Cinematographic documentaries as far back as 1896
http://www.britishpathe.com/

Tubidy Mobile
Part of the You Tube collection, in formats for mobile devices
http://tubidy.mobi/

Content safety

The Internet, and in particular the World Wide Web, is not always the clean place that it ought to be, where reliable information could be found for free like in a huge, worldwide public library. Regrettably, there are certain individuals who publish materials of dubious reputation and unsavoury bad taste. Like me, for instance.

For protecting the innocent against so unqualifiable elements as I am, there are some institutions whose task it is that of labelling as "safe", "maybe safe, maybe not", or "definitely unsafe" the content of documents that have been published, and that have been remitted to those intitutions by their own authors (the persons or organisations who created the documents), or their current maintainers. The labelling is mainly based on concepts of morality and on language used, although different labelling institutions also have different criteria for this. The idea is primarily targeted to children, or to other persons who do not tolerate immorality or harsh language.

The document thus labelled is expected to insert a PICS label (Internet Content Safety) in the head of the document, where search engines or user agents are expected to recognise the label and act in consequence. The PICS label cannot be inserted in the body of the document, although a warning text may also be shown in the body. Depending on the label, and on the features and configuration of the operating system or the user agent, the document will be shown with a warning, or it will be refused altogether. Some administrators go too far, refusing essentially innocent documents through their systems just because the PICS label merely suggests a possibly 'controversial' topic.

Counters of visitors

A counter of visitors counts how many times an Internet document has been opened for reading (this is, how many times a copy of the document has been requested from its host server). A counter may also show some statistical information, for example the origin of the request (redirected by a hyper link or not), the date and time when the document or each of its pages have been opened (therefore showing which pages have been read and the time for each), which out-bound hyper links the visitor has followed, if any, and many other details, such as the computers used by those visitors, their operating systems, their user agents, the colour and size resolution of their video boards, the country of origin of the request, the human language preferently used by the target computer, and plenty of other technical data.

All those facts can be used to redirect the visitor to an appropriate copy of the document (in a different human language, for instance), or they can make the Web Master aware of general preferences of visitors, and thus to manage the content of the document accordingly. Automatic redirection should not be used alone, internal links activated by manual operation should always appear on each page of the document. The reason is that a human operator may prefer to read in a certain language, in German, for example, but he is at the moment using a computer located in Italy or with Italian configured as the preferential language. He should have the easy means for going to the German page without need of re-configuring the computer (or of moving the computer and himself to Germany !!!), which may prove difficult or impossibe to do.

The company below, Extreme Tracker, really goes overboard in providing a richness of technical detail such as makes sophisticated Web Masters happy.

Extreme Tracking
Counter of visitors with full statistics
http://extremetracking.com/

For redirection of a document request to another Uniform Resource Locator, please see the appropriate section further below in this page:

Redirection of Uniform Resource Locator

Courses through the Internet

Courses made through computer connected to the Internet differ from courses made in classroom only in the absence of physical presence of teacher and students, because in everything else it is pretty much the same: there are subjects programmed for study, a method for teaching them, a chronogramme, tests and examinations, et cetera.

The advantage is precisely the freedom of not needing to go physically to school. Teacher and students "meet" through computer at scheduled times, while being free to study at their own pace at other times. However, they MUST keep a discipline of study. The institution will not tolerate students coming and going at their whim, it will promptly eliminate rascals from the on-line course. Therefore, persons lacking the necessary time or resources (reliable Internet connection), should abstain from starting the course.

Massachusetts Institute of Technology
Courses through the Internet
http://ocw.mit.edu/

Duplicated documents in the Internet

Documents published in the Internet or in any of its parts (like the World Wide Web) belong to their authors, who are free to keep them, modify them, or remove them, just like in any other distribution medium. Of course, it is justified to quote them by other authors, and it may even be justified to reproduce parts of them, but in these cases it is correct to inform of the source and give credit to those who took the trouble of writing the texts. The aim of the Internet is to create a source of information that is free for everyone to use, not to plagiarise the efforts of creative writers and give false credit to shameless individuals who are too lazy or too stupid for making any creations of their own.

Copy Scape
Duplicated or plagiarised documents in the Internet
http://www.copyscape.com/

Games in the Internet

There are thousands of games available in the different protocols of Internet, mostly in the World Wide Web. Games for all tastes: action, adventure, board (such as chess or draughts), cards, puzzles, tests of knowledge in different fields, and many others. Some can be played on-line against the host computer or against human opponents, others require a user agent capable of executing Java, Java Script or other languages for dynamic content, still others can be downloaded and played off-line against the local computer, or using the local computer screen as a reference for two or more human players. All computer platforms and operating systems have games available for them in greater or lesser amount. Even the oldest or most limited device can execute some games. Of the vast repertoire in existence, only two games have been chosen here. The first is the oldest and most international game of intelligence, the King of Games: chess. The hyper-link below is useful for playing on-line.

Chess

Delorie
For playing chess in real time against Delorie Chess computer
http://www.delorie.com/

Readers are invited to visit the Chess Page of CSS Dixieland, which includes other hyper-links related to chess, chess history, advice, and sample games:
cssdixieland_chess.html

Dungeons

There is a kind of adventure games often known as 'dungeons', after the name of the earliest of its kind, 'Dungeons and Dragons', a game played on a table, or for main frame computers, that Wizards of the Coast released in the late 1960's and in the 1970's. Another game of a similar concept called 'Rogue' was created by Glenn Wichman and Michael Toy in 1985, developed by Kenneth Arnold and Michael Toy in 1986 for BSD, and subsequently ported to other Unics systems by Timothy Stoehr. Rogue is a game that outputs text and simple graphics, as opposed to the text-only output that was predominant at that time in adventure games. The original BSD Curses screen-handling library was put together by Kenneth Arnold, mainly to support graphic games, and the development of Rogue popularised the use of the Curses library for various other purposes, not only for games. Since then, Curses has become one of the most important application libraries in Unics.

Other 'dungeon' games such as Omega, Larn, Angband, Moria, Hack or Nethack, all took off from the inspiration provided by Rogue. The game Diablo for Microsoft Windows, though much more intensive in graphics, has a very similar play logic. There are also several 'dungeon' games for mobile devices, as well as collective games for several players, connected through a computer network. The game known as 'Hack' was created by Jay Fenlason, helped by some other programmers. Hack was further developed by Andries Brouwer, and ported to IBM Personal Computer or compatibles by Don Kneller, with the name of 'PC-Hack'. From the latter games Net-Hack was created by Mike Stephenson, and from this several other games have evolved. Net-Hack is one of the oldest games today available in Internet, having been ported to many platforms until version 3.4.3 of 2005, but currently most platforms have been abandoned. Thus, from DOS to Unics, almost any computer HAD a Net-Hack port for it, but this is not so with the most recent versions of Net-Hack (see notes after hyper-links).

Net-Hack is a graphic game of adventure that can be played either on-line or off-line. This outstanding and complex game puts the player in a labyrinth of many levels of depth, full of monsters, magic objects, weapons, armour, and countless other items. The goal is to find a magic amulet and escape from the labyrinth. The player starts by choosing one of several characters, and must care for his hero while advancing towards his goal. He will find all sorts of strange things that may be either beneficial or harmful. He must know what decisions to take. The game is turn-based, like chess, without time limit. The Net-Hack Development Team commanded by Mister Mike Stephenson is very supportive and will answer all kinds of doubts related to their game. Players of Nethack can read the instructions and dive directly into the game, or they can also consult Web documents or Usenet groups with a dedicated community of players who offer plenty of good advice. Sometimes the advice may disclose 'secrets' that the player may prefer to discover by himself. This kind of advice is often known as 'spoiler'. Net-Hack Web document, maintained by Mister Kenneth Lorber:

Net Hack
The most complex graphic adventure 'dungeon' game for a single player, on-line or off-line
http://www.nethack.org/

There are two ways to contact the Development Team of Net Hack. One way is the Contact page at the above Web document:

Net Hack Contact page
For comments, suggestions, or report of problems with Net Hack in any of the computer platfoms for which the game has been ported
http://www.nethack.org/common/contact.html

The other way is by electronic post. Preferable for programmers who wish to send a patch to the Net Hack source code, or for other major collaborations:

devteam AT nethack DOT org

The string "AT" must be substituted by the character "@" and the string "DOT" by the character "." without surrounding spaces and in single horizontal line. This is to thwart automatic harvesting of links (often for spamming purposes).

Notes on the most recent versions of Net-Hack:

Until version 3.4.3 of 2005 Net-Hack was a very portable game. It could be played in a wide array of computer architectures, with different processors and operating systems, such as Amiga, Atari, DOS, Be OS, VMS, Unics, Windows or Macintosh. Unfortunately, there was a fake release called 'Net-Hack 3.5', unauthorised by the official Dev Team of Mister Mike Stephenson. The release of the spurious '3.5' forced the Dev Team to prepare an official release as 'Net-Hack 3.6', and make it available in 2015 from the official Net-Hack Web document of Mister Kenneth Lorber, hyper linked above. However, version 3.6 was put together in a rather hasty way, after ten years without any official release, and only ports to Apple Macintosh and Microsoft Windows are for now available. DOS, Unics, and all the other platforms, have been forsaken. The source code of Net-Hack is freely available, and there is one page in the Web document where persons interested in porting the game to other platforms can announce their releases, but so far, only Macintosh and Windows ports exist in the official Web document hyper linked above.

Mister Lorber lamely 'justifies' the decision of the Dev Team by declaring that the other ports 'are not used' at present. Quite wrong, and an offence for the enthusiasts of those other platforms. There are computer lovers who treasure their old machines, still in working condition, or who use their old operating systems. Relics such as CP/M in Intel 8086 (or even in Intel 8080) are known to have some devoted users even today. They have Internet presence. Luckily, the vast world of Computing is not limited to the ubiquitous Windows, or to the Macintosh made 'for the rest of them', for the mass of ignorants who know nigh to nothing about computers. There are experienced computer operators who prefer to work with DOS, Unics, or other platforms, for advanced tasks such as programming or for other serious purposes, and who WILL NOT surrender to the market pressure of popular hardware and software vendors. It is a pity that the Dev Team had not understood this when labelling those platforms as 'not used'. Only old versions of Net-Hack are now left for 'the rest of us'.

Fortunately, there are some operating systems or some of their distributions that have gone through the pains of installing Net-Hack from the sources, making it available as an executable. In some cases this executable presents small images known as 'graphic tiles', which represent the hero, the monsters, or the other objects that appear in the game. In other cases the executable presents only textual characters. The game is the same with graphic tiles or with textual characters. More important are the options defined at the time of translating from source to executable, or the options defined by the system administrator, or the options defined by the player himself. There are MANY such options for Net-Hack. The player is advised to read the manual and make his own decisions, or to experiment with the many possibilities.

Groups of interest in the Internet

Finding a group of people interested on a particular subject may yield better results than querying a search engine about that subject, because the group of enthusiasts will often be eager to welcome other persons interested in the subject that they know and they love, and therefore the members of the group will usually be ready to help the newcomer, answering questions and doubts with plenty of relevant information. It may require some time to find the right persons, though, as well as it will be necessary some diplomacy for not offending sensitive individuals. But the results almost always pay high.

Google Groups
Groups with interest on specific subjects
http://groups.google.com/

Besides Google Groups, there are many other Internet resources with similar purpose, to put in communication individuals who share a common interest. This can be done in a forum or bulletin board, where people can write ideas or comments, and read what others have written. It can also be done by subscription to an electronic mailing list, where participants receive or also send informations. The Usenet Newsgroups Protocol is entirely devoted to this kind of interaction. In fact, part of Google Groups is taken from Usenet and transferred to World Wide Web, since the two protocols are not compatible.

Warning: in many of those resources, particularly in Usenet, there are almost always individuals who post irrelevant content, some of them even offensive content. Most groups (but not all of them) have one or more moderators, whose task is to edit or remove inappropriate content. Before writing to any group it is recommended to read the rules for that group. They may appear as "Terms of Service", "Conditions of Use", "Frequently Asked Questions", or similar names. It is also good to read for some time before writing anything, so as to perceive the relevance and tone that predominate in that group. In case of doubt, it is advisable to request help from a moderator or from other members.

Hackers and crackers

The term "hacker" began to be used inside the Massachusetts Institute of Technology during the early 1960's. Originally it was applied to computing enthusiasts who were extremely knowledgeable on the inner workings of a computer, and who applied this expertise for naughty but inoffensive actions. With the demise of the "time sharing system" and the spread of microcomputers during the late 1970's and the 1980's, the label of "hacker" was increasingly applied by the public media to individuals who stealthily performed mischiefs of different kinds with computers, ranging from the merely humorous to the downright criminal. From the modifying of Web documents of some company or of some government agency without their permission, to the collecting of secret personal or corporate information for doubtful purposes. Therefore, the word "hacker" became almost synonymous of "computer intruder", although it was not properly its original meaning. "Cracker" is a more correct term, when applied to a computer intruder.

In the section of Reference and Dictionaries further below there is a hyper link to Wikipedia, encyclopaedia that can be edited by its readers. Wikipedia has a wealth of information on almost any imaginable topic, like few resources in the Internet have. One of those topics regards hackers. Some interconnected pages of Wikipedia explain this concept in detail, and offer many hyper links to expand knowledge on this exciting subject. The hyper link below also possesses excellent lines of research into the whole topic, including its historical and technical aspects. A word of warning for would-be "hackers": many governments have increasingly enacted laws against certain forms of computer crime. What may be taken as a joke without any consequences, may also be taken as an illegal activity liable to prosecution. Besides, the technical sophistication that is needed for "hacking sport" is very high (depending on the kind of hacking activity and against whom). At any rate, doing it seriously is not a week-end past time, it is a full-time business.

Hack in the Box
A "Jack in the Box" with detailed information on hackers
http://www.hackinthebox.org/

Hosts (servers) of Internet documents

A Gopher or Web document, or any other kind of data set, has to be stored into some computer in the World. If that document or data set must be made available through the Internet, through a Bulletin Board Service, or through any other kind of network, then the storing computer must be connected to the Internet or to that other network, ideally 24 hours a day and 7 days a week, except for maintenance. The computer that stores the document or data set is called a 'host' or a 'server'. A number of host servers accept Web documents for free, and at least one host server (Super Dimension Fortress) accepts Gopher documents for free or for a symbolic contribution. This hosting may be done in exchange for advertisements that are inserted in the hosted document, or in exchange for posting information in a forum or bulletin board, or for some other forms of collaboration or contribution, but such participations may be only suggested or encouraged, not always required. Other host servers are paid, and obviously they do not insert any advertising and do not require any extra efforts from the Gopher or Web Master.

Some hosts are reliable, some are not (they may be off-line too often). Some hosts will only show documents coded in static HTML, others will correctly show dynamic documents that use copy-righted, scripting proprietary languages, such as ASP of Microsoft Corporation or Java of Sun Systems. Some hosts will only allow small documents below 50 Kilobytes or even less, others allow mastodontic documents ranging in the level of several Gigabytes (the maximum limit for each data set is usually below 500 Megabytes). Some hosts will be very restrict when it comes to allow band-width, other hosts are extremely generous in giving lots of band-width. Some have plenty of resources or may install those resources upon request of a relevant number of their users, others offer only the most basic resources. Because all those characteristics are never together in the same host, it is for the Gopher or Web Master who owns the document to decide on the right host to be chosen. What works well for a certain Master or a certain document, may not work for another.

Free host servers for World Wide Web documents

The next two hyper links list many host servers that accept storing Web documents without payment. There is plenty of relevant information about those hosts, including favourable or unfavourable comments written by some of their users. Readers of CSS Dixieland are invited to send to those lists their own comments about the hosts that they use.

Free Web Hosting List
Servers where Web documents can be hosted
http://www.free-web-hosting-list.com/

Free Web Hosts
Servers where Web documents can be hosted
http://www.free-webhosts.com/

The next hyper link has a different purpose from the others. The forte of Web Page Test is to test the availability of a Web document from the server where that document is hosted, measuring retrieval time of the document from the host. This helps a Web Master in checking efficiency of server and routing. Unfortunately, Web Page Test does not directly work for Gopher servers.

Web Page Test
Tests the availability of a document from its host
http://www.webpagetest.org/

Free host servers for Gopher documents

As said above, Super Dimension Fortress is one of the VERY FEW, or perhaps the only free Gopher host that still remains as of 2021. All the others are gone with the wind. Information is given in the CSS Dixieland page devoted to the Gopher Protocol. The page can be visited by activating the following internal link:

cssdixieland_gopher.html

Hyper links pointing to Internet documents

Hyper links shown in a Gopher or Web document that point to other documents are called "outbound hyper links". It is easy to see them, just by looking at the document that lists them (or looking at its source code, in case that any hyper links might be hidden under very small text or under text of the same colour as the background). Not so easy is the opposite way, "inbound hyper links", this is, hyper links that point to a given document from a number of unknown documents. The thing is important, because a hyper link pointing to another document is a positive judgment about the value, originality or exclusivity of the target document. There is a hyper link below that will help to locate some of the source documents pointing to a given target document.

Widex
Documents hyper linked from other documents
http://www.widexl.com/remote/link-popularity/index.html

Identification of domains

We may wish to identify the person or institution possessing a given domain of the Internet, if we find an interesting document in that domain, or for another reason. Some countries keep strict records of the owner of every domain under their jurisdiction, other countries are looser about domain identification, therefore there is no guarantee that the owner of a domain be always identified, but the lists offered by the two hyper links below are probably the best way to start that kind of search.

Better Who Is
Names and Internet Protocol numbers
http://www.betterwhois.com/

DNS Stuff
Domain Name Servers
http://www.dnsstuff.com/

Number of views of Internet documents

Good to know how our document is ranking in the Internet, it greatly boosts the ego of a Web Master. It may also be interesting, although maybe not so personally boosting, to know the ranking of documents belonging to other Masters. Warning: the hyper link listed below will only show the ranking of documents that are received by client computers using the Alexa toolbar, which is available for free download from Alexa Corporation.

Alexa Ranking
Number of views of Web documents
http://www.alexa.com/

Operating systems: Introduction

There was here a long explanation on the concept of operating system, giving historical and technical details that were really beyond the scope of the introductory purpose of this section. Readers seriously interested in the subject have plenty of information in Internet, or in paper books. Of the many operating systems that exist or have existed, two genealogies have been chosen by CSS Dixieland as deserving a complete view: the DOS genealogy (in particular Free-DOS) and the Unics genealogy (such as BSD, Minix, Linux, Solaris, and others). For those operating systems, please see the pages on Free-DOS and on Unics, accessible through the internal links below. For general information on operating systems, including DOS and Unics, continue reading this page.

cssdixieland_freedos.html

cssdixieland_unics.html

Operating systems: Comparison

There is below a good list of operating systems to choose, all of them for free. Some of them are open source for all or part of the system, at least for the kernel or kernels, and with licence to modify the system by rewriting and recompiling the sources in order to suit the needs or preferences of technically sophisticated persons. Note that permission to modify the system does not automatically imply permission to redistribute the modified system.

Keep in mind, however, that some systems may be incomplete or unreliable, or they may only work with obsolete or uncommon hardware, or they may have a too limited or too specialised availability of software. Read the comments written by other people about a certain system. If necessary post Yourself specific questions in a relevant board. At any rate, give a try to the unknown system in an empty and formatted hard disk or another storage volume, or else boot-strap the system from a floppy disk, compact disk, or another removable volume, before thinking on doing partitions to the hard disk or on any other actions that might compromise the future operability of Your computer.

Free Operating Systems
Detailed comparison and information on many free systems
http://www.freeos.com/compare/

Absolutely THE OLDEST Unics open source system in common use today is Minix (meaning 'Minimal Unix'), created in 1987 by Mister Andrew Tanenbaum of Vrije Universiteit at Amsterdam. Minix has a microkernel, not a monolithic kernel as it is the case in most other Unics systems. Minix versions 1.x of 1987 and 2.x of 1997 were partly intended as teaching tools, showing how an operating system could be built, but Minix version 3.x of 2006 is a fully functional system, with important enhancements made in 2009. The Minix version 3.3 of 2014 is distributed as a 'live' (a boot-strappable) compact disk, this is, the system can be used with no more than a compact disk in the computer. Even without a hard disk, a Universal Serial Bus storage device, or another boot-strappable volume, a fully functional command line is available directly from the compact disk. Minix includes software made by BSD, by the Free Software Foundation, and by other third parties, with the corresponding licences. Minix is not part of BSD, but many executables made for BSD work well in Minix and vice-versa. The Minix Web document includes an editable wiki.

Minix
The oldest open source Unics operating system, distributed as a 'live' compact disk
http://www.minix3.org/

From the technical point of view (albeit not from the legal point of view) BSD is one of the many variants of Unics. Most current BSD systems derive from 4.3 BSD Lite operating system, a version of Unics developed by the Computer Systems Research Group at the University of California at Berkeley between 1975 and 1993, and from the 386 BSD operating system, which was the first port of BSD to Intel 80386 processor. The acronym "BSD" means "Berkeley Software Distribution". In the following years, modifications from the 4.4 BSD Lite system (the last release from the CSRG at Berkeley) were integrated into other BSD systems.

Operating systems: For old or limited computers

Not every computer can load mastodontic operating systems like Windows Vista of 64 bits, which takes several Gigabytes of space. Luckily enough, those mastodonts are not necessary in the minimal. In the hands of a knowledgeable operator, many things can be done with a much more modest system, like for instance the systems included here. Some of them take less than a hundred Kilobytes of memory, including the kernel and a few of the most necessary application programmes. This is the case of MS-DOS 1.25, marketed in 1981 by the same company that later produced Windows (Microsoft Corporation), twenty years before they fancied the dubious idea of building mastodontic systems.

All Boot Disks
Operating systems ready for boot-strapping. Several versions of MS-DOS collected here
http://www.allbootdisks.com/

Free Personal Computer Technician
Operating systems in floppy disc image, with kernel and most necessary programmes
http://freepctech.com/

The system of choice for using the maximum resources of an old or limited computer, even with a small Random Access Memory, a small video memory, and without hard disc (using the system as floppy disc-only or compact disc-only system), is without any doubt Free-DOS, the system for the computer enthusiast who really knows. Free-DOS is the most complete DOS system that has existed.

Free-DOS was created in 1994 as an open source alternative to the MS-DOS system of Microsoft Corporation. The first stable version of Free-DOS was released in 2006, after many beta test versions. Free-DOS works only with the architecture of the IBM Personal Computer or compatible, using Intel x86 processor or compatible. Besides the hyper link to Free-DOS given below, this document of CSS Dixieland has a page entirely dedicated to Free-DOS, with detailed technical information on many aspects of this wonderful system:
cssdixieland_freedos.html

External hyper link to the Free-DOS Project. The official distribution is in boot-strapabble compact disk. Persons wishing or needing to have Free-DOS in boot-strappable floppy disk, should look for the Odin distribution from the Free-DOS project, or for the Fuzoma distribution of educational software (hyper link to Fuzoma is given in the Free-DOS page of CSS Dixieland, above).

Free-DOS
Command line operating system of 16 bits
http://www.freedos.org/

Operating systems: Programmes for CP/M

In 1973 there were arithmetic calculators and some other electronic devices that used microprocessors, but the smallest general-purpose computers were the so-called 'minicomputers' of the PDP series, built by Digital Equipment Corporation. The 'minicomputers' were the size of a wardrobe (but 'mini' when compared to the huge mainframe computers), they costed thousands of Dollars, and they required operation and maintenance by experts. At the end of that year Mister David Ahl of Digital Corporation built only one unit of the first prototype of microcomputer, the Scelbi-8 H, which in the following months incorporated the 8-bit microprocessor Intel 8008. This first microcomputer also incorporated the first magnetic floppy disk. The Scelbi-8 H microcomputer was never sold commercially, but it gave ideas to other pioneers, among whom were prominent the members of the 'Homebrew Computer Club', an innovative group of sophisticated computer enthusiasts led by Mister Lee Felsenstein.

Also in 1973, Mister Gary Kildall (who at the time worked at Intel) developed an operating system of 8 bits that he initially called 'Control Programme for Microprocessors', abbreviated as CP/M. He initially offered CP/M to Intel, but the corporation showed only a limited interest. Intel was interested in selling its microprocessors to factories that needed to control industrial processess and assembly lines, and it had only a very secondary interest in selling microprocessors for small electronic devices. The company did not see the tremendous potential of the future personal computers, at a time when the only computers in existence were big, costly, and complicated machines. After three years trying to convince Intel, Mister Kildall formed his own company, the 'Intergalactic Digital Research', which marketed CP/M in 1976 with the name of 'Control Programme for Microcomputers' or 'Control Programme Monitor'.

In 1974 another landmark was planted by Mister Johnathan Titus, the 'Personal Minicomputer Mark-8', a microcomputer of 8 bits also based on Intel 8008. It had 2 Kilobytes of Random Access Memory, extensible to 16 Kilobytes. It only accepted machine code (in numbering base of two), and it was sold just as paper plans, without physical parts. Only enthusiasts of Electronics had the skills for building a computer themselves, and working with it in machine code, but it represented a step ahead. The real breaktrough came in the following year, with the Altair microcomputer.

In June 1975 Mister Edward Ted Roberts of Micro Instrumentation and Telemetry Systems released the Altair 8800, microcomputer of 8 bits based on Intel 8080. It had only 256 bytes of Random Access Memory and 64 Kilobytes of storage, input by manual switches and output by panel of ligths. Units began to be sold in 1975 at a price of 300 Dollars as a kit with all its physical parts and assembling instructions, or else sold as a finished microcomputer at the price of 400 Dollars. Initially it accepted only code in numbering base of two for all of its input or output operations. Later it added elements to reach 7 Kilobytes of Random Access Memory and accepted Basic programming language, adapted to Altair 8800 by Messieurs Paul Allen and William Bill Gates of Micro-Soft Corporation. Another team incorporated as peripherals a reader of perforated paper tape and a keyboard. This modified microcomputer was sold at 500 Dollars.

Also in 1975 the University of California in San Diego released the P-System, an operating system of 8 bits, which was marketed by Softech Microsystems. It had several versions.

Finally, as mentioned above, Mister Gary Kildall formed Intergalactic Digital Research and in 1976 released the CP/M operating system. In a short time and until the early 1980's most microcomputers had the CP/M system or were programmable in Basic, resident in Read Only Memory. Some microcomputers had the P-System, and a few top of the line had one of the variants of Unics.

DR-DOS was an improvement on CP/M made by Digital Research. Being initially a strong competitor against PC-DOS and MS-DOS, it was made open source after the demise of Digital Research.

Then the sad story comes. Shortly before 1980 Mister Tim Patterson of Seattle Computer had built an operating system that he called QDOS, or 'Quick and Dirty Operating System'. It was of 16 bits, and strongly based on CP/M-86, another operating system of 16 bits produced by Digital Research. It happened then that the 'Big Blue' (affectionate name given to IBM, the International Business Machines Corporation) had decided to enter into the microcomputer business. The old multi-national corporation was building the 'Personal Computer', based on Intel microprocessor, and it needed a suitable operating system for it. The original 'Personal Computer' of IBM had very limited hardware, it could not execute Unics at all.

Thus, the Big Blue began looking for a solution. The company tried to deal for the P-System, but the University was not interested. Senior IBM executives also contacted Digital Research, but Mister Kildall did not even attend them, he would not negotiate under the condition of absolute secrecy imposed by the IBM representatives. Then they desperately turned to Microsoft. Messieurs Paul Allen and William Bill Gates had already written Basic interpreters for Altair, for Apple II and other computers, and for CP/M operating system. They had a deal with Mister Kildall, under which Digital Research concentrated on the operating system and Microsoft on application programmes.

However, when Mister Gates knew that Mister Kildall had not even attended the dignified old gentlemen of the Big Blue, then Mister Gates declared that the agreement between Digital Research and Microsoft had come to an end. Thus, in 1980 Microsoft bought the QDOS Quick and Dirty Operating System from Seattle Computer, changed its name to 86-DOS (86 Disk Operating System, for use with Intel 8086 microprocessor), introduced a few modifications, and licenced it to IBM as PC-DOS for the Personal Computer. Microsoft kept the right to sell the system separately as MS-DOS. Foul play from the part of Microsoft. This company later produced some outstanding professional software (such as the Quick Basic translator and QBasic interpreter), but it is fair to recognise that its trajectory has not always been of exemplary honesty.

When Digital Research knew what Seattle Computer and Microsoft had done, and the gullibility of the Big Blue, it threatened to sue all of them for break of patent and plagiarism. IBM was alarmed at the prospect, and this time it negotiated with Digital Research without forcing non-disclosure agreement. Mister Kildall finally came to terms, and agreed to have CP/M as alternative operating system for the Personal Computer. This famous microcomputer was publicly announced in August 1981, and the first units sold at the end of that year. The series became immediately successful, initially based on Intel 8086, originally incorporating PC-DOS operating system, with the option of a 16-bit version of CP/M, and programmable in Basic.

Regrettably, CP/M was priced much higher than PC-DOS, and most customers saw no reason to choose CP/M. An IBM Personal Computer with PC-DOS was sold at an extra of sixty Dollars, but an identical microcomputer with CP/M costed an extra of two hundred and forty Dollars ! Thus, CP/M gradually lost market share, while PC-DOS and MS-DOS became predominant. Digital Research made strong exertions to compete against Microsoft. The most significant effort was the release of DR-DOS (Digital Research DOS), which the corporation developed after its own CP/M, although very modified. For ending the sad story, with the demise of Mister Kildall who died in 1994, and of Digital Research, CP/M was completely abandoned except by a group of enthusiasts, active as of 2021 and hyper-linked below. DR-DOS was taken by Novell and then by Caldera, and made open source. Unforgettable relict of Computing History.

Working with CP/M is feeling the fragance of the good old times, back in the second half of the 1970's, those heroic times when computers were still a rarity, and the chosen few who worked with computers REALLY KNEW how to work with them. There was no other option, since the operating systems were all based on text written at a command line prompt, and no graphic icons existed. The thing would have been too cryptic for many people of today, who lack the minimal idea of how a computer works. They just 'click' the button of a table mouse or another pointing device on one or another of several funny icons in a 'desk top'. There are usually no parameters given by command line. Instead, there are 'pull down menus' or other visual aids for choosing various options. The user can be a perfect idiot. In fact, the more idiot that those stupid ignorant users become, the better for commercial fool catchers, advertisers and vendors, to extort advantageous business from the ubiquitous donkeys.

By comparison, CP/M is a treasure of a software. Still a few enthusiasts cling to it and even improve it beyond the point in which it was inherited as a bequest of the legendary Digital Research. Below there are some hyper links to the most complete lists of programmes available for the CP/M operating system. The system itself can be downloaded and executed, often from a floppy disk, mainly in one of three ways:

-In one of the computer models for which CP/M was originally intended, using Intel 8080 of 1974 or compatible processors. Those computers are very rare pieces of collection nowadays, therefore not easily available. The CP/M versions for those computers are from the second half of the 1970's. When CP/M 86 was released in the early 1980's, for Intel 8086 of 1978 or compatible processors, then the earlier versions of CP/M were retroactively called "CP/M 80" (meaning "Intel 8080" or compatible processors).

-In a compatible computer of more recent production. For example in an IBM Personal Computer or compatible, with Intel 8086 or compatible processors. As it has been said above, versions of CP/M called "CP/M 86" were made for those platforms in the early 1980's, and computers of that kind are the most common until today, therefore this is probably the most obvious solution for working with a real CP/M system at the present time. CP/M can be boot-strapped from a partition (slice) in hard disk, or from an entire hard disk, but CP/M is so small that it can be just boot-strapped from floppy disk.

-In a computer while running another operating system. In this case CP/M is not a real operating system as in either of the two cases above, it is simply an executable programme that emulates approximately the behaviour of a CP/M system. Different emulators of CP/M exist, at least for Unics systems (BSD, GNU Hurd, Linux, Minix...), for DOS systems (Free-DOS, DR-DOS, PC-DOS, MS-DOS, PTS-DOS, ROM-DOS...), for DOS boxes under Windows, or for Apple Macintosh. Possibly for other operating systems as well. Besides the emulator itself, programmes are often included for converting from the CP/M data set system to another data set system, both ways. That conversion is necessary for working with floppy disks formatted for CP/M or containing CP/M data sets in them, without having a real CP/M system available. The CP/M sector size is of 128 bytes, while that of DOS is usually of 512 bytes, and this is one of the reasons for incompatibility between the CP/M system and the FAT 12 (File Allocation Table) system that is always used in DOS-formatted floppy disks (although DOS can format floppy disks for 128 or 256 bytes of sector size if necessary, but that formatting is now uncommon).

Zimmers
Programmes for CP/M operating system
http://www.zimmers.net/anonftp/pub/cpm/

Retrotechnology, Mister Herbert Johnson
Resources for CP/M and other software made by Digital Research
http://retrotechnology.com/dri/

CP/M and Zilog Z-80, Mister Gaby Chaudry
Resources for CP/M system and for Zilog Z-80 processor
http://www.cpm.z80.de/

Operating systems: Programmes for DOS

If not so deliciously old flavoured as CP/M, we may at least recognise that DOS systems offer more resources, if only because they were developed some years later and also because they lasted longer in the market (CP/M system predominated only five years, from 1976 to about 1981, while DOS systems predominated fifteen years, from 1981 to about 1996). The difference is notorious, in the number of programmes made for CP/M and those made for the various sub-systems and versions of DOS. Working with CP/M is mainly done today for the sake of treasuring a classic jewel. Not to detract the system at all, because it allows to do good things to those who know how to do them, but the truth is that CP/M stopped development too early, and as a consequence it does not offer many resources today. DOS systems, on the other hand, are a REAL PROPOSAL for doing serious work with a computer even today. A look at the hyper links listed below will convince many sceptics that DOS systems can perfectly be considered efficient and reliable for many purposes, although for some purposes, such as accessing the World Wide Web or Universal Serial Bus, they somewhat lack updated software or the software is scarce.

General collections of programmes or resources

The first hyper-link concentrates solely upon DOS systems. The next offers software for DOS as well, but it really has non-DOS systems as the main focus. Note, however, that Windows 1.0, 2.0, 286, 3.0, 386, 3.1, 3.11, 3.1 For Workgroups, 3.11 For Workgroups, and 3.2 (for the Chinese market), produced from 1985 to 1993, are simply graphic interfaces executed on top of MS-DOS, or of another DOS system. Windows as the true system began only with Windows 95, in 1995. It means that a computer with versions of Windows produced in 1993 or earlier, can work with a stand-alone DOS system or with those Windows versions, coexisting without problems. Therefore any software that had been developed for DOS will be perfectly executable by the MS-DOS originally included with early Windows versions, which is not always the case with Windows 95 or later, whose MS-DOS dialogue boxes contain MS-DOS version 7 or MS-DOS version 8, both of them of fewer resources than the last stand-alone version, MS-DOS 6.22 of April 1994.

Opus, Dave
Programmes exclusively for DOS operating systems
http://www.opus.co.tt/dave/

Vetusware
Programmes for DOS and for other systems
http://vetusware.com/

Dendarii
Resources for DOS operating systems
http://www.dendarii.co.uk/DOS/

Angel Fire
Resources for DOS operating systems
http://www.angelfire.com/mo/dossource/

UX 1, B. D. Bensley
Huge collection of old programmes for DOS
http://www.ux1.eiu.edu/~bdbensley/pdsoftware.htm

The Bensley Collection

The Bensley Collection of old programmes for DOS, hyper linked above, is offered for free as a single data set of huge size, almost 45 Megabytes, compacted by the Zip algorithm. It must be expanded by that same algorithm, which in the case of Free-DOS it is done by the UNZIP.EXE programme. With that executable in the current working directory or in the environment path, and with the compacted data set also in the current working directory, then the expansion can be done with a command similar to the following:

UNZIP -S PDS.ZIP

The -S switch tells UNZIP.EXE to convert spaces to dashes, which is necessary for DOS (when not using a Long Name driver). The switch is preceded by hyphen (-), not by slash (/), because UNZIP.EXE has been ported from Unics and the hyphen is the standard switch character in Unics (in DOS it is normally the slash, though Free-DOS can also be configured for using the hyphen as switch character). With the command given above, PDS.ZIP will create in the current working directory a new directory containing over 1 500 sub-directories, with almost 11 000 data sets, occupying about 150 Megabytes. If not wishing or not being able to expand that monster inside the current working directory, then UNZIP.EXE can be instructed for expanding into another volume or partition, optionally with creation of a new directory (unnecessary, because PDS.ZIP will create it anyway). The help of the expanding algorithm summarises those options, explained in more detail in its documentation: FREEDOS\DOCS\UNZIP

The Bensley Collection is perhaps the biggest availability of executables for DOS that exists in a single place of the Internet. Most of the collection is from the 'Personal Computer Software Interest Group' in Sunnyvale, California, a society of microcomputer enthusiasts who were very active in the 1980's. The collection has well-explained tutorials for DOS systems and for Basic, Pascal and some other languages, software for programming in Assembly, Basic, Pascal, Forth, Fortran or others, utilities for many different purposes, varied games, and plenty of other programmes for all tasks imaginable, from the elementary to the advanced. Even the most experienced will find much of his interest.

However, a note of warning must be given: a part of those programmes come in the form of .COM or .EXE executables, but others expect to be started from a .BAT batch script or from a .BAS source for an interpreter of Basic language. They also expect to be executed from a floppy disk. Such actions were common in the 1980's, when most of those DOS programmes were created, but it may not be the case for most computers thirty years later. For the .BAT batch scripts the solution is not to execute them, but to read them carefully with a text editor or viewer, or by the TYPE | MORE command, and to perform manually the necessary operations at the command line, or appropriately modify the scripts.

Difficult as that work is, for the .BAS sources the situation is even worse. The computers of those years often included a Basic interpreter in their Read Only Memory. That is not the case today, thus the interpreter must be called from the command line and given the .BAS source to be interpreted. Example:

BWBASIC FROBU.BAS

The above example assumes BWBASIC.EXE (Bywater Basic, the only Basic interpreter included in Free-DOS) in the current working directory or in the environment path, and an imaginary Basic source called FROBU.BAS also in the current directory. The problem, however, is twofold: first because that Basic source may expect a floppy disk or another such medium, common in the 1980's much more than it is now. Therefore the Basic source must be modified with a text editor. Second problem and really serious: the Basic dialect for which the .BAS source was written might have been IBM BASICA, Microsoft GWBASIC, Microsoft QBasic, or other dialects of Basic frequently used in those years, but with different keywords (or the same keywords but with different behaviour) from the instruction set of the Bywater Basic interpreter. In that sad case, there is no other solution but trying to find in Internet the appropriate Basic interpreter, which may prove difficult when the correct one expected by the .BAS source is not even informed in the documentation.

Even the .COM or .EXE executables cannot always be used directly by a modern computer. The reason is that the speed of 1980's microprocessors was much slower than the speed of today, because most current microprocessors possess cache memory besides higher clock oscillation frequency of the piezoelectric component. A solution might be found using a programme such as CPUCACHE.COM, SLOWINT1.COM, SLOWDOWN.COM or FDAPM.COM, all of them available in Free-DOS, which will make the microprocessor operate at a lower speed. WARNING: the documentation of those programmes must be read carefully before using them.

One final note regarding the old programmes of the Bensley Collection: their authors often expected some voluntary one-time contribution from users who liked the programme and who used it regularly. The author requested to send a small monetary contribution to a postal address, or by contacting the author via a Bulletin Board Service. Again another problem thirty years later: most of those Bulletin Boards do not exist anymore. The postal address may still exist, but the author of that old software may or may not be found in there after thirty years. He may even not be alive at present. Probably the best honour that could be given to his memory is making his programming effort useful, by making his old programme a currently workable software until today, if really finding it of quality. Perhaps no higher token of respect could be paid to the efforts of those pioneer programmers of bygone years.

The concept mentioned above is called 'Shareware', initially developed by Mister Bob Wallace of Quicksoft, who programmed a full-featured text editor called PC-Write. Programmes under Shareware can be freely distributed under certain conditions imposed by the author, and a small payment is expected from those persons who like the programmes and use them regularly. Other programmes exist that are under the 'Freeware' concept, initially developed by Mister Andrew Fluegelman. The term 'Freeware' is trademark of The Headlands Press, but after the mysterious death of Mister Fluegelman, the property of the term has not been legally enforced, and it is used now by other persons. Freeware means that the programmes can be used for free, and distributed or modified by anyone, only acknowledging the name of the original programmer.

In Shareware or Freeware the programmes may have a legal owner, but there is a final legal group of progammes called 'Public Domain', where no one legally owns them (although they may have an historically recognised author). It may be so due to one of two causes: or because their author or legal holder at some point chose to release the programmes to the Public Domain, or because a number of years has passed and they have naturally fallen into the Public Domain. The number of years depends on the legal jurisdiction, on the kind of intellectual property, such as software, patented invention, literature, sound or image (music, graphic art, photography, cinematography, et cetera), and on either the life of the author or else the year when the work was released or was published for the first time, or when it was legally registered.

Image

Image formats have gradually become more standard than they were in the 1980's or the early 1990's, first because many of the old formats have for the most part fallen out of common use, and second because there has been a work on unified specifications of existing formats (such as JPG), or on creation by international organisations of standard and non-proprietary formats (such as PNG, by the World Wide Web Consortium). The first programme below is a small image viewer, originally intended for tiny portable computers (palm tops), but which can perfectly be used by any computer executing a DOS system. The second programme is an image viewer in more than forty formats. It can modify some characteristics of the image, and convert between some of those formats.

Lx Pic, Mister Stefan Peichl
Image viewer for DOS, version 7.3 of 2002
http://hplx.pgdn.de/

Pict View, Mister Jan Patera
Image viewer and format converter for DOS, version 1.94 of 2000
http://www.pictview.com/

Drawing, painting

As it has been noted when speaking of image formats, most drawing or painting programmes made for DOS systems in the 1980's or early 1990's absolutely lacked any concept of unified standards. Some of them could produce relatively complex illustrations, or even animations (the DANCAD 3D programme stored in the huge Bensley Collection), but those images had to be viewed exclusively by a copy of the programme with which they had been created. Such a fastidious situation meant that if sending the image to be viewed from another computer, a copy of the creating programme had also to be sent along. That solution was perhaps possible for communication amongst a few computers, but definitely it is not a proposal for a vast network, such as the Internet.

The hyper link to the Bensley Collection given further above is a really huge bazaar of old programmes for DOS. It contains nothing less than some dozens of drawing, painting or other graphic illustration programmes, from simple to complex, nearly all of them released in the 1980's, and NONE OF THEM capable of producing a single standard format. Only one programme can work with an old version of GIF, the Graphics Interchange Format of Compuserve, but the operation of that programme is so cumbersome as to make it almost useless. The Pict View image viewer also given above can open images in over forty formats, but in spite of that versatility, IT CANNOT OPEN ANY IMAGES produced by any of those programmes (save the already mentioned GIF). A fastidious situation that makes those old programmes useful only for a group of related computers or a local area network, where all the machines possess a copy of the drawing or painting programme. Those exclusive formats make their images practically unexportable to distant computers.

They cannot efficiently be published in the hyper text protocols of Internet, such as Gopher or World Wide Web, since it would require to provide a link to a server whence the drawing or painting programme could be downloaded, and instructions on how to execute that programme. In practice that is unfeasible, because the person wishing to view the image would have to quit the Gopher or HTML user agent, or to open a second shell of the command interpreter, just for viewing the image, then to return to the Gopher or HTML session. Sure, the programmers of the 1980's or early 1990's had not in mind a World Wide Web that still did not exist, when not even the Gopher protocol existed yet (the Web began in 1990 inside the CERN of Genevre and was made public in 1993, Gopher in 1991). If those programmers had the Internet in mind at all, they could only think of the File Transfer Protocol for transferring images AND their viewing programmes. In most cases they did not even consider that possibility. Most software distributions were done hand to hand, by physical post through the Mail, by electronic post, or by bulletin board services.

Sound

Sound has not had the problem of multitude of incompatible formats that image has had, probably because until relatively recent times most computers lacked sound, except for the primitive internal computer speaker. The internal computer speaker is in fact intended just as a beeper for warning the human operator of actions performed by him or by the machine, but since its sound can be adjusted by software for frequency, duration and interval (intensity is adjusted by hardware), then it follows that the internal computer speaker can be used to produce music. The Basic programming language can be used for that purpose, and there are also specific programmes for DOS systems that can be used to compose music playable through the internal computer speaker. A technically primitive music by modern taste, but exportable to almost every computer. The Bensley Collection hyper linked above has some of those music-making programmes.

HTML, Hyper Text Mark-up Language

Out of the many Web user agents collected at Evolt below, at least six were specifically created or modified for DOS. Two of them are graphic user agents: Arachne and Web Spyder. The other four are text-only user agents (images or sounds can be displayed by means of a separate programme): Bobcat, DOS Lynx, Minuet and Net Tamer.

Bobcat or Net Tamer can be executed even with old computers having the 16-bit Intel 8086 processor of 1978, or compatible, although with that old processor they will be slow for normal operation. DOS Lynx is a conversion for DOS of the Lynx text-only user agent that had originally been made at the University of Kansas for the Unics and the VMS operating systems, but DOS Lynx needs the 32-bit Intel 80386 processor of 1984, or compatible, it will not work at all with an older processor. DOS Lynx needs a packet driver, even for browsing local documents, and oddly enough no network packet driver has been included in the distribution of DOS Lynx. Only a fake packet driver called Nullpkt has been included for local browsing. Besides this limitation, DOS Lynx needs almost 600 Kilobytes of Low Conventional Memory, which may imply the need of boot-strapping the DOS system with less than 40 Kilobytes, out of the 640 Kilobytes of maximum executable programme size in the Megabyte of Low Conventional Memory that can be directly accessed by DOS in Real Mode.

Begun in 1996, Bobcat can be considered a simplification of DOS Lynx. Bobcat works better with HTML (Hyper Text Transfer Protocol), but it also acts as a client for FTP (File Transfer Protocol), Gopher (University of Minnesota), Telnet (Tele Network), and WAIS (Wide Area Information System). E-07 is the latest version of Bobcat. Because Net Tamer, Bobcat or DOS Lynx browse only text and textual hyper links and do not waste any time displaying images or sounds, they are perfect browsers for old or limited computers, or for networks with slow connections, when textual content be more important than graphics, audio or video. If necessary, images or sounds can still be shown separately, opening their hyper links and using, for instance, Lx Pic, Pict View, or similar programme, linked above. Minuet is an adaptation for DOS of a user agent that has its own operating system, also called Minuet.

Evolt
Collection of HTML user agents
http://browsers.evolt.org/

Archivers, compressors

Compression is used for diminishing storage space or also for handling a shorter sequence of bytes when transmitting data from a computer to another, especially through a network. A compressed programme or document CANNOT be used directly, it first needs to be expanded to its original full size. Some programmes for compression, such as Double Space or Drive Space (included in some versions of MS-DOS), silently perform this expansion when a compressed data set be called from the command line prompt, and silently compress it again when execution of the data set have been finished. Other programmes for compression need to be specifically called for executing their compressing or expanding. The rate of compression depends on both, the programme used for compression and the data set that is to be compressed. Entire volumes can in theory be compressed, real (physical) volume, such as floppy discs or hard discs, as well as logical (virtual) Random Access Memory volumes.

Not all data sets can be compressed, however, and even those that can be, may under some circumstances be rendered useless or may even crash the computer system, after being expanded and being then called for execution. In these cases, the expanded data set is not identical to its own original before the compression. Therefore it is not recommended to rely solely on a storage of compressed data set, it is a good idea to keep an original full size copy of every important data set stored under compression. A data set compressed with a certain programme can only be expanded with that programme, otherwise it is lost. There is a diversity of programmes for compression that can be used with CP/M, DOS, or other operating systems.

Squeeze is one of the oldest compression algorithms, UPX one of the newest, and plenty of others lie in between. Info Zip, listed below, is a monster with a down-load size of over 60 Megabytes !!! It sounds ridiculous, to have a programme for diminishing the size of others, when the programme used for that purpose is in itself many times bigger than even the operating system (if working with DOS, for instance). Having been already warned against the risks of compression, a computer operator must exercise sound judgment on what to compress, by which programme, and how to use it. And ALWAYS keep an original full size copy of every important compressed data set, or accept the risk of losing it.

Info Zip
Compressor for DOS
http://www.tmk.com/infozip/

Logical volume in Random Access Memory

The original programmes for MS-DOS (and their equivalents for DR-DOS or for other DOS systems) called HIMEM.SYS (extended memory manager), EMM386.EXE (expanded memory manager) and RAMDRIVE.SYS (logical volume in Random Access Memory) are all limited to a maximum of 32 or of 64 Megabytes, although in fact most computers of the XXI century feature much more Random Access Memory. Such programmes were written in the 1980's or early 1990's, a time when most microcomputers had no more storage space than 64 Megabytes per volume (in a hard disc, for instance), therefore it was thought unnecessary to complicate the software by giving access to bigger volumes. Many of those computers in fact lacked hard disc, they operated with floppy discs only.

The set of programmes written by Mister Marko Kohtala (latest version released in 2005) modify or substitute the three mentioned DOS original programmes. An obvious purpose of such a modification is the creation of a logical volume. A logical (also called virtual) volume is of excellent utility for holding any temporary data sets, but the data sets would completely be lost if turning off, restarting or resetting the computer, therefore a logical-virtual volume should not be used for permanent storage. This set is compatible with MS-DOS versions 3 to 7, DR-DOS versions 5 to 6, or Free-DOS version 1, and includes mainly these programmes:

XMSSIZE.EXE modifies HIMEM.SYS Extended Memory Manager for over 64 Megabytes. Operable with a processor at least Intel 80286 or compatible.

Three device drivers modify HIMEM.SYS or EMM386.EXE for over 32 Megabytes:
SRDXMS.SYS, XMS 2.0 Extended Memory, modifies HIMEM.SYS.
SRDEMS3.SYS, LIM/EMS 3.2 Expanded Memory, modifies EMM386.EXE.
SRDEMS.SYS, LIM/EMS 4.0 Expanded Memory, modifies EMM386.EXE.

LIM/EMS is the Lotus - Intel - Microsoft specification for Expanded Memory. Extended or Expanded Memory allows programmes to access available Random Access Memory beyond the limit of 640 Kilobytes of maximum executable programme size in the Megabyte of Low Conventional Memory that can be directly accessed by DOS in Real Mode.

SRDISK.EXE works with one or more of the above device drivers to create a logical volume of up to 4 Gigabytes, if having enough memory for it. It may substitute RAMDRIVE.SYS or it may coexist with it.

Resizable RAM Disc, Mister Marko Kohtala
Set of programmes to create logical volume in Random Access Memory
http://sourceforge.net/projects/srdisk

Free-DOS includes the executable programme SHSURDRV.EXE that can create several logical volumes of fixed size in Random Access Memory, each volume being up to 4 Gigabytes of size, if having memory for it. Other alternatives are VDISK.SYS (Virtual Disk, which like RAMDRIVE.SYS must be installed via FDCONFIG.SYS or CONFIG.SYS and cannot be re-sized or removed), XMSDSK (which can be installed or removed from the command line, not from FDCONFIG.SYS or CONFIG.SYS), TDSK (Turbo Disk, which can create volumes of up to 64 Megabytes of size, if having memory for it), and a few others.

The comparison below was extracted by Clarence Verge for Arachne, from the documentation of TDSK Turbo Disk:

                             RAMDRIVE.SYS  VDISK.SYS     TURBODSK
                    (MS-DOS, WINDOWS 3.x)  (DR-DOS 6.0)  Vers 2.1
Maximum size                    32 Mb      32 Mb         64 Mb
Low memory support              Yes        Yes           Yes
XMS memory support              Yes        No            Yes
EMS memory support              Yes        Yes           Yes
Extended memory by INT 15h      No         Yes           No
Entries at top level directory  4-1024     4-512         1-65534
Bytes of sector size            128-1024   128-512       32-2048
Dynamic memory allocation       No         No            Yes
Programmable cluster size       No         No            Yes
32-bit bus used by 386 or 486   No         No            Yes
Low memory used by MS-DOS 5.0   1184-1232  2096-2608     432-608

MS-DOS 5.0 transfer in Kb/second, sector 512 bytes, RAM vol in XMS
386-25 MHz (no cache)           17105      6838          17095
486-25 MHz (8 Kb cache)         10278      7370          10278

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