bill.gunshannon at hotmail.com
Sat Nov 30 19:17:01 CST 2019
On 11/30/19 7:16 PM, Fred Cisin via cctalk wrote:
> On Sat, 30 Nov 2019, Bill Gunshannon via cctalk wrote:
>> I'll start with the simple and funny one. If i run FORMAT
>> it formats all 80 tracks. :-) Seems like the definition
>> for an 8" disk as selected in the config menu is just plain
>> wrong. Of course, once it formats all 80 :-) tracks any
>> attempt to access it, like a DIR, just returns "sector not
> A lot could depend on how the software is interpreting the FDC return
> In the case of PC BIOS (765), error code number 4) that would mean that
> it did format; it sees sectors, but not the one that you asked for.
> That may be that the format command setup and the read are in
> disagreement on sector numbers, and/or sector size.
> It could also happen if it ended up on the wrong track. (then the C
> field of the CHRN of the sector doesn't match the C field of the CHRN
> Even a non-functional stepper could do that. Be well aware thet
> "VERIFY" checks whether there are READABLE sectors, not whether they
> have correct content. If you want RELIABLE code, include a READ after
> WRITE, rather than rely on the FDC "VERIFY".
> A non-functional WRITE (including FORMAT) will VERIFY just fine, but
> leave behind whatever had been on the track before, rather than what you
> though that you had put there.
> PC FDC returns error code 2 for not seeing address mark. However,
> MS-DOS goes through a short list of codes that it knows, and then falls
> through to "error, but none of the above" and says "General Failure" (I
> can't help but think that that was one of the brass in VietNam)
I think you missed something. This is a P112 SBC not a PC. I watch
the head step from track to track until it runs into the stop after
passing the last real track. I have a dbit 8" adapter and it displays
the track count and I watch it go from 0 to 79. I am assuming the
problem is that wherever the disk parameters are being stored on the
P112 they are wrong for 8" disks.
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