There were a couple of outfits (one in Walnut Creek), who made kits to
convert Selectrics into computer printers!
On Fri, 27 Jan 2023, Chris via cctalk wrote:
@ Fred - " ...in Walnut Creek..."
C: any affiation to WC CD-ROM? Wiki says they were around in ms-dos says.
No, not related.
The Escon typewriter conversion kits were long gone before CD-ROMs,
possibly before 5150! And, by that time, Tandy offered more affordable
printers, and IBM sold what seems to be a re-badged Epson MX-80, so there
was no longer need desperate enough to convert Selectrics.
https://vintagecomputer.ca/escon-selectric-kit/
https://vintagecomputer.ca/files/Escon/
It is unlikely, but not impossible, that there could be overlap of people
involved.
The company official address (and corporation) was listed as San Ramon,
but warranty service was in Pleasant Hill, and there were retail sales
out of Walnut Creek.
Walnut Creek CD-ROM started in 1991
The first official MS-DOS support of CD-ROMs was 1984? in DOS 3.10 (that
is "three point ten", not "three point one" (Int 21, function 30h returns
3 in AL and 0Ah in AH))
It included MSCDEX and used redirection; since MS-DOS did not support
drives larger than 32MB until 3.31, the "redirector" made the CD-ROM look
like a remote drive "on the network". Try doing a CHKDSK of a CD-ROM.
MSCDEX was supported on 3.10 on, but was not included in MS-DOS
distribution until 6.x, and/or Win3.11
(Win setup/install for 3.00 and 3.10 were eventually available on CD-ROM!)
MSCDEX aparently uses the [undocumented] Int 2Fh network redirestor.
It can be patched to work with DOS 3.00, and a few people did claim to
have created programs to access CD-ROMs in DOS from 2.00 on!
In addition to MSCDEX, DOS also needed drivers to access the CD-ROM drive.
Those were specific to the controller card. ASPI simplified SCSI access.
--
Grumpy Ol' Fred ci...@xenosoft.com
