15 May
2007
15 May
'07
4:10 p.m.
I have a tarbell floppy controller card that has been rewired to access
3.5" disks using a standard PC 3.5" disk drive. I have 3 disks that the
Altair can boot off of and read, but my windows computer can't do anything
with them. I've tried rawread.exe and diskinfo.exe and they both choke on
the disk. I assumed that if a disk could be written with the standard 3.5"
disk drive on the tarbell card then it should also be read on the same
drive connected to a modern IBM compatible.
The disks are 720K style, they don't have the high density hole.
I was hoping that these disks would be an easy way to move data to and from
the Altair.
The version of CP/M is 1.4.
What could be missing? If the bitrate is fixed, then is CP/M not writing
standard sectors? Rawread says "Address not found" and diskinfo says the
drive is not ready.
Grant
15 May
15 May
6:12 p.m.
Grant Stockly wrote:
I have a tarbell floppy controller card that has been
rewired to access
3.5" disks using a standard PC 3.5" disk drive. I have 3 disks that the
Altair can boot off of and read, but my windows computer can't do
anything with them. I've tried rawread.exe and diskinfo.exe and they
both choke on the disk. I assumed that if a disk could be written with
the standard 3.5" disk drive on the tarbell card then it should also be
read on the same drive connected to a modern IBM compatible.
The disks are 720K style, they don't have the high density hole.
I was hoping that these disks would be an easy way to move data to and
from the Altair.
The version of CP/M is 1.4.
What could be missing? If the bitrate is fixed, then is CP/M not
writing standard sectors? Rawread says "Address not found" and diskinfo
says the drive is not ready.
Grant
The tarbel card is the single density version or is a double density one?
One way to tell is 1771 single density only, 1791 or 1793 double density capable.
If single density then some PCs FDC cannot do SD, some can.
Allison
6:15 p.m.
On Tue, 15 May 2007, Grant Stockly wrote:
I have a tarbell floppy controller card that has been
rewired to access
3.5" disks using a standard PC 3.5" disk drive. I have 3 disks that the
Altair can boot off of and read, but my windows computer can't do anything
with them. I've tried rawread.exe and diskinfo.exe and they both choke on
the disk. I assumed that if a disk could be written with the standard 3.5"
disk drive on the tarbell card then it should also be read on the same
drive connected to a modern IBM compatible.
Not necessarily.
What are the specifics of the format that the Tarbell controller is
writing on those disks?
6:33 p.m.
On Tue, 15 May 2007, Grant Stockly wrote:
I have a tarbell floppy controller card that has been
rewired to access
3.5" disks using a standard PC 3.5" disk drive.
[snip]
What could be missing? If the bitrate is fixed, then
is CP/M not writing
standard sectors? Rawread says "Address not found" and diskinfo says the
drive is not ready.
I take it you don't have access to a Unix machine? The dd command might
be able to fish out something more from that disk. Specifically, the
utility cpmtools is useful for writing to a variety of disk formats and is
easy to customize for new formats.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
8:45 p.m.
On 5/15/07, Grant Stockly <grant at stockly.com> wrote:
I have a tarbell floppy controller card that has been
rewired to access
3.5" disks using a standard PC 3.5" disk drive. I have 3 disks that the
Altair can boot off of and read, but my windows computer can't do anything
with them. I've tried rawread.exe and diskinfo.exe and they both choke on
the disk. I assumed that if a disk could be written with the standard 3.5"
disk drive on the tarbell card then it should also be read on the same
drive connected to a modern IBM compatible.
Are you using a 1771 based SD Tarbell card, or a 1791/1793 based DD
Tarbell card? That might make a difference.
9:01 p.m.
On 5/15/07, Grant Stockly <grant at stockly.com> wrote:
I have a tarbell floppy controller card that has been
rewired to access
3.5" disks using a standard PC 3.5" disk drive. I have 3 disks that the
Altair can boot off of and read, but my windows computer can't do anything
with them. I've tried rawread.exe and diskinfo.exe and they both choke on
the disk. I assumed that if a disk could be written with the standard 3.5"
disk drive on the tarbell card then it should also be read on the same
drive connected to a modern IBM compatible.
Without more information, the best anyone can do is try to read your
mind.
Here's my try.
You're putting an 8" format on a 3.5" drive. Perhaps the drive
you're using uses pin 2 as a density select and completely ignores
the extra HD hole in your 720K disk.
That's sort of the opposite of recording a 720K format on a 1.44M
disk--the cure there is to cover the HD hole in the 1.44M disk. If
the reverse were true, you'd drill (or punch) a hole in the 720K
floppy.
Cheers,
Chuck
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5 comments
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ajp166＠bellatlantic.net -
cclist＠sydex.com -
cisin＠xenosoft.com -
dgriffi＠cs.csubak.edu -
glen.slick＠gmail.com -
grant＠stockly.com