Some IBM XT issues

[Narishma]

I am using PCem r283 configured as such: IBM XT, 1MB of RAM, 30MB HDD with XTide, PC-DOS 2.10.

In recent versions I can't seem to be able to change floppy disks. The first one works fine but trying to swap a new one in results in disk errors in DOS. This used to work fine in PCem v9.

Drives don't seem to work in ROM BASIC either. I can't load or save files from ROM BASIC (neither disk BASIC nor advanced BASIC), and one I exit back to DOS, trying to access any drive results in disk errors. This one didn't work in v9 either.

Finally, Is there a way to specify less than 1MB of RAM? Some old applications (like Wordstar 3.0's configuration tool) won't start if you have more than 512K of RAM. They complain about not having enough memory. It could also make the boot process faster since there's less memory to scan through.

[te_lanus]

Also got this problem with the XT range. The "new" amixt don't boot due to this error

[nerd73]

EDIT: This seems like a problem with the HDD emulation.
Try installing it on the 286/386/486 clone and then running the HDD on the XT clone.
Newer EDIT: Yep, that one way to get DOS 5.0 installed on the XT clones.

dos5.PNG (9.05 KiB) Viewed 15749 times

[te_lanus]

a few questions:

A) will the XT get fixed to use it's Floppy Drive.

B) does it support 360kb images (and 160/180/320kb)? Tried a few Booter games (Alley Cat, Frogger) and it ignores the disks inserted.

[ppgrainbow]

I am using PCem r283 configured as such: IBM XT, 1MB of RAM, 30MB HDD with XTide, PC-DOS 2.10.

In recent versions I can't seem to be able to change floppy disks. The first one works fine but trying to swap a new one in results in disk errors in DOS. This used to work fine in PCem v9.

Drives don't seem to work in ROM BASIC either. I can't load or save files from ROM BASIC (neither disk BASIC nor advanced BASIC), and one I exit back to DOS, trying to access any drive results in disk errors. This one didn't work in v9 either.

Finally, Is there a way to specify less than 1MB of RAM? Some old applications (like Wordstar 3.0's configuration tool) won't start if you have more than 512K of RAM. They complain about not having enough memory. It could also make the boot process faster since there's less memory to scan through.

I'm looking at the source code for mem.c and found that it is possible to specify the memory allocation less than 1 MB. The only draw back is that the amount of memory allocated on the machine will need to be changed to read "KB" and limiting the value between 64 KB to 262,144 KB in 64 KB increments.

[Battler]

In recent versions I can't seem to be able to change floppy disks. The first one works fine but trying to swap a new one in results in disk errors in DOS. This used to work fine in PCem v9.

The new FDC code is very broken. 40-track disks (such as 360 kB) don't work properly on either drive, and drive B doesn't work at all.

[ppgrainbow]

In recent versions I can't seem to be able to change floppy disks. The first one works fine but trying to swap a new one in results in disk errors in DOS. This used to work fine in PCem v9.

The new FDC code is very broken. 40-track disks (such as 360 kB) don't work properly on either drive, and drive B doesn't work at all.

I can reproduce this issue on the Award SiS 496/497 and AMI Win486 machines - drive B indeed does not work at all.

I'm getting a "Not ready reading Drive B" error message when trying to read 360 KB and 1.2 MB floppy diskettes on drive B. Until a fix it made, we're pretty much stuck at r305.

[te_lanus]

Something I noticed.

When you switch from an 286+ machine to a XT machine it'll be able to read any floppy. But starting an xt machine from scratch it won't read any floppy (except an 1.44M. Disk)

[SarahWalker]

I can't reproduce any of this at all...

Any more details?

[SarahWalker]

Okay, was able to reproduce the drive B issue. Should be fixed in rev 321.

[te_lanus]

Checked thiss morning and imbxt, genxt & dtkxt all boot alleycat booter. The rest fails. The junoxt don't want to do anything and crashes pcem with rev 322, it work on rev 320

[Narishma]

Checked rev 322 and the issues I reported in the first post are still present.
To reproduce them, set up a basic ibmxt machine (8088 4.77mhz, cga, 1mb memory).
Boot from a DOS floppy image (I tried PCDOS 2.10 and 3.30).
For the first issue, just run BASIC (it's in the first floppy on DOS 2.x and in the second floppy in DOS 3.x), then exit back to DOS with the "system" command. You should now get a disk error if you try to access the disk in any way.
For the second issue, boot the machine as before, then load a different floppy image on the same drive and try to access it. You should get a disk error again. I don't know if the two issues are related.

[SarahWalker]

Still can't reproduce this. Can you give more information about your setup - Windows or Linux, what GCC version, what IBM XT BIOS version, what XTIDE version?

[Narishma]

I think it was a bad BIOS ROM.
I did a fresh install on a different computer and none of these issues appeared. The only thing I did differently was download the BIOS instead of copying it from the other machine.
Sorry to have wasted your time.

[te_lanus]

Thanx to Tom all the problems is no more, that I can see.