Wordmark Systems
2705 Pinewood Dr.
Garland, Texas 75044

November 7, 1988

Dear Mr. van Nisselroy,

MYDOS has been very significantly improved since I released version 3.08. In fact, version 3.08 was the first one sold generally. Automatic density detection, support for 35, 40 and 80 track single and double sided drives, 8 inch (or high density 5 1/4 inch) drive support, RAMdisk support for the 130XE and most of the RAM upgrades for the 8-bit Atari computers (up to 1 megabyte) and support for most of the hard disk drive systems made for the Atari 8-bit computers have been added one at a time. The current version is MYDOS 4.3. I am still supporting version 3.016 as well, since it is so much smaller than version 4.3 (3.016 is smaller than DOS 2.0, and 4.3 is perhaps 800 bytes larger).

I do not plan any really extensive changes to MYDOS myself, but because there are several people interested in one extension or another I am releasing the source code and some tools to build custom, enhanced versions of MYDOS. This kit form of MYDOS will be posted to Compuserve and Genie here in the United States and if you know of a similar forum for distributing "freeware" in Europe, I would be glad to send you a copy to distribute there.

MYDOS's structure is very much like Atari DOS 2.0 and 2.5, and as a result, adding a command line interpreter or date and time stamping of files (like SpartaDOS) is quite difficult. On the other hand, I have already (several years ago) generated a ROM version of MYDOS for the 400 and 800 computers, and adapted it to the XL and XE computers that came along at almost the same point in time.

I modified a version of MYDOS 3.016 shortly after the 800XL computer was released that I called RDOS (originally ROMDOS, but with 2 versions being RAM loaded, that seemed to be a poor choice of a name). RDOS rapidly went from version 0.0 to 1.0, 1.1, 1.2 and ended its history as 1.4 (all in perhaps 8 or 10 months). The ROM version of RDOS could be programmed in an EPROM and run from the memory at COOO-CFFF with or without a disk drive on the system. The other two versions were loaded into RAM, either under an OSS Supercartridge or in the normal location at $0700.

The supercartridge version provided most of the same features as the ROM version (taking only 400 bytes of the 48K memory space over that taken by the disk buffers allocated. The other that was loaded into low RAM much like the standard MYDOS but it shared the same boot sectors as the ROM version and the under-the-cartridge version, permitting a disk to be built that would run it if no C000 ROM were present and no OSS Supercartridge were present either. Version 1.4 added the ability to run under the built-in BASIC of the 800XL and 130XE as weIl. Unfortunately, I only shipped a few test copies of these programs.

To answer your last question, the ATR8000 is (was?) a peripheral device for the Atari computers that combined one serial port, one printer port and up to 4 disk drives (either 8 inch or 5 1/4 inch) and included a Z80 microprocessor. It was manufactured by a company in Texas called SWP Microcomputer Products.

The ATR8000 (and its unfortunate successor, the ATR8500, with much better serial I/O support) were designed originally as CP/M machines and were also available with the CP/M operating system and several Atari programs to permit the Atari computer to be used as a dumb (or smart) terminal to the CP/M computer in the perpheral box. It was an excellent design and a reliable product, but it simply cost too much for the Atari market (the 130XE was priced at $170-$200 at one time, while the ATR8000 was sold at $750-$900 at the same time, with no disk drives and no CP/M operating system).

I will send you information on the changes being applied to MYDOS in its new incarnation as a more or less public domain operating system if you would like, also.

I hope I have been helpful, and I look forward to hearing from you again.

Sincerely,

Charles Marslett