Something in DOS 7 requires a 386, by my experience.

I would just use DOS 5 or 6.

Yeah, 7.x needs 386 or higher to function.

my parallel cd interface won't work with the older 16 bit dos versions.
even the test program testport.exe locks up.
360k floppy win95b doesn't boot either.
You can't format and make bootable the usual way in win95,you have to get into dos mode and go to the windows\command folder and use sys.com
That will burp and say no room for command.com.You get rid of doublespace.bin and add command.com manually.
The msdos.sys is the 6 byte one.3 files and you have a bootable 360k win95 floppy.
I put the other needful things like fdisk and format.com on other floppies with more room.

xtgold wrote on 2020-03-18, 12:38:

my parallel cd interface won't work with the older 16 bit dos versions.

Are you aware that the parallel cd interface is not compatible with an XT anyway if it needs a version of DOS that can't be used on an XT?

Or maybe DOS is not the problem and the software simply needs 286+ instructions. Using a NEC V20 could help in this case.

that was the selling point of the parallel cd, it was supposed to work on the xt.
the 1994 dos 7.0 wouldn't boot either.it has the old fashion io.sys and msdos.sys and was released in the win3.1 days.
release date was 1-1-94

Version 2.06 - dated 1996 - diskette label indicates 'models 163550, 164550, 165550'.
Known to work on 8088 based PCs, such as the IBM 5150 (IBM PC) and IBM 5160 (IBM XT).
When unzipping, ensure that the 'preserve folders' (or similar) option is enabled.

MS Dos 7.x was never sold as a stand alone product. 7.0 came with win95 rtm and 7.1 came with win98 rtm.

xtgold wrote on 2020-03-18, 22:28:

that was the selling point of the parallel cd, it was supposed to work on the xt.

Then why do you mess with DOS 7.x, which won't ever run on an XT? If it is supposed to work on an XT, use DOS 5.0 or even 3.3. And check the readme of the software version you use. Maybe it's too new and only older releases were able to work on an XT.

Tiido wrote on 2020-03-17, 20:59:

Yeah, 7.x needs 386 or higher to function.

I can sort of confirm that. Firt saw this issue in the 90s with one my father's boot disks.
He had a 386DX40 with Win95 RTM, while I had a 286 with DOS 6.2.
When I booted his DOS 7.0 diskette, a message appeared, saying, that it required a 386 or better CPU..

if you look at the io.sys with a hex editor you see the requires 386 or better message in ascii

derSammler wrote on 2020-03-19, 07:36:

xtgold wrote on 2020-03-18, 22:28:

that was the selling point of the parallel cd, it was supposed to work on the xt.

Then why do you mess with DOS 7.x, which won't ever run on an XT? If it is supposed to work on an XT, use DOS 5.0 or even 3.3. And check the readme of the software version you use. Maybe it's too new and only older releases were able to work on an XT.

driver v1.06 ,v2.06 doesn't work on the xt for the parallel cd or any other pc
v4 does work on a celeron 550 in old dos,so I am trying to match os since I can't match the processor or speed
if I can't get a cd working on the xt it is pretty much useless
I can't keep loading 360k floppies
I can't disable the built-in floppy controller so can't modernize that( I have add in cards)

PC-DOS 7 will run on an XT, but I think you're missing the mark entirely by focusing on DOS version

Are you using the right drivers? I have no idea which parallel cdrom model you are trying to use but some had specific drivers for XT:. example: http://minuszerodegrees.net/backpack_cdrom/ba … kpack_cdrom.htm

xtgold wrote on 2020-03-19, 13:18:

driver v1.06 ,v2.06 doesn't work on the xt for the parallel cd or any other pc v4 does work on a celeron 550 in old dos,so I am […]
Show full quote

derSammler wrote on 2020-03-19, 07:36:

xtgold wrote on 2020-03-18, 22:28:

that was the selling point of the parallel cd, it was supposed to work on the xt.

Then why do you mess with DOS 7.x, which won't ever run on an XT? If it is supposed to work on an XT, use DOS 5.0 or even 3.3. And check the readme of the software version you use. Maybe it's too new and only older releases were able to work on an XT.

driver v1.06 ,v2.06 doesn't work on the xt for the parallel cd or any other pc
v4 does work on a celeron 550 in old dos,so I am trying to match os since I can't match the processor or speed
if I can't get a cd working on the xt it is pretty much useless
I can't keep loading 360k floppies
I can't disable the built-in floppy controller so can't modernize that( I have add in cards)

Are ypu sure it;s the driver an not the paralall interface itself? You may need to upgrade that because of the newer uart. Networking is another option to consider.

supposedly on the commandline for the driver you can specify uni/ecp/epp
I have the ebox program from days of old to hook 2 computers together via serial or parallel for drive sharing.
Naturally I can't find my cables.
I can share a cd or bigger drives from a more modern pc.
I assume a cd,it may be only disk drives.
with v4 driver the cd is detected and works but it kills the keyboard.
Their port testing program also kills the keyboard (testport.exe)
porttest.exe works fine with a loopback connector.

BinaryDemon wrote on 2020-03-19, 14:26:

Are you using the right drivers? I have no idea which parallel cdrom model you are trying to use but some had specific drivers for XT:. example: http://minuszerodegrees.net/backpack_cdrom/ba … kpack_cdrom.htm

I don't know either
It is just the bare circuit board.
I think it was the 8x,I wasn't impressed with the drive just the guts and tossed the drive years ago.
Found the interface when I dug the xt out of storage.
I tried all the drivers.
Windows driver works fine.
v3.06 seems to be missing from the collection,if there ever was one.
v2.06 says for 286 but I get the divide by zero error on a celeron 550

Caluser2000 wrote on 2020-03-19, 02:05:

MS Dos 7.x was never sold as a stand alone product. 7.0 came with win95 rtm and 7.1 came with win98 rtm.

I found it today if you want to play with it,on a win3.11 hardrive.

looks like a kludge from the 1994 win 3.11 days
16bit fat only
puny io.sys and msdos.sys

It won't boot on the xt

It was never inteeded to work on an XT.... PC Dos 7.0 was.