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Zenith Z-100 can read early 8" 86-DOS disks

It's a little sketchy using this 86-DOS 1.14 os but of course it's just experimental. However, using the Z-DOS/MSDOS 1.25 bios with the 8" SSSD mod seems very solid
with reading writing files to an 8" SSSD 86-DOS 1.x type disk.

Larry G
 
retrogear said:
It's a little sketchy using this 86-DOS 1.14 os but of course it's just experimental. However, using the Z-DOS/MSDOS 1.25 bios with the 8" SSSD mod seems very solid
with reading writing files to an 8" SSSD 86-DOS 1.x type disk.

Larry G
Click to expand...
Of course, because it's really just a hack and 86-DOS is not 100% compatible with MS-DOS 1.20 and later. However, with this 86-DOS 1.14 OS, you should be able to read/write 86-DOS 0.x disks :).

Sincerely,
Pig
 
yes it does. Here's the .34 C 8" disk. This is where it gets sketchy. From 86DOS 1.14 boot if I try TYPE C:NEWS.DOC it starts displaying it then locks so hard I need to reset.

86dos.34c.JPG
 
almost like it tries to process an interrupt in the middle of it and can't handle it.
Sometimes just DIR C: will lock too.
Hmmm it seems to occasionally lock doing DIR C: on any 86dos version disk before even accessing the disk.

Larry G
 
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The lockups! That's the stack overflow I mentioned earlier. Compare my v1 and v2 sources and apply the stack switching code to your BIOS source.

Sincerely,
Pig
 
I see in your v2 you have stack wrappers available for all bios calls but only enabled them on disk read / write. Would enabling more or all slow things down or increase file size too much ?
Just curious. BTW I'm currently using your v1 source with a few of my tweaks.

Larry G
 
Would certainly kill performance if you enable all of them (I did that for the IBM PC ports, to work on modern computers). Size growth can be neglected. Personally, I would try enabling them for read/write first.

Sincerely,
Pig
 
Enabling the disk r/w causes it to lock before it reads command.com. Without those enabled I get the occasional lock sometimes with a scrolling wild interrupt message. I owned a Z-100 decades ago and I remember
getting wild interrupts trying to run pc software. Back then I had a lot less information than I have now.

Larry G
 
retrogear said:
Enabling the disk r/w causes it to lock before it reads command.com. Without those enabled I get the occasional lock sometimes with a scrolling wild interrupt message. I owned a Z-100 decades ago and I remember
getting wild interrupts trying to run pc software. Back then I had a lot less information than I have now.

Larry G
Click to expand...
What if you change the stack buffer from 256 bytes (DW 128 DUP(?)) to 512 bytes? It works in the emulator if I do that.

Sincerely,
Pig
 
That's much better. It can read a V .34 8" in C: When I try from A: TYPE C:NEWS.DOC it displays a few paragraphs then blizzards with wild interrupts.
Same trying to type a text file on a v1.0 disk. Should I increase more ?
 
Actually it has finished the disk read buffering by then. Would it be another function like character io that needs a stack buffer ?
I suppose it could be at the point where it's going to read the disk again but it had buffered several tracks before displaying.
 
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scratch all that. I forgot to activate the jread and jwrite. It seems adding any jcall just locks it up
 
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