Bill Gunshannon bill.gunshannon at hotmail.com
Mon Dec 2 19:11:06 CST 2019

On 12/2/19 4:55 PM, Dennis Boone via cctalk wrote:
>   > Well, I have the dBit FDADAP.  Works great.  I have used them before
>   > on a PC to access PDP-11 disks from PUTR and E11.  The P112 claims to
>   > support 8" but I am finding it unlikely.  If it (well, at least the
>   > OSes it runs) don't even know it only has 77 tracks I can't see how
>   > anyone has done 8" disks on it.
> I went spelunking in the ROM and BIOS sources the other day, and I don't
> see any 8" drive stuff in there at all -- it's all 3.5" and 5.25".  I
> looked at FORMAT too.  Am I looking at old code?

The menu you get when you hit Escape on startup has an option
for setting a floppy as 8".  Mine is ROM 5.7 which I believe
is the next to last.  Unless it is different than the other
CP/M systems I have FORMAT should have no hardware dependent
code in it.  It was the OS that tracked and controlled what
the underlying format of the floppies were.

>   > Why am I getting this sneaking suspicion that none of this stuff
>   > actually works?
> I haven't had mine out in a while, but last I did, the GIDE did work.
> Seems like there was some ordering of operations on HD setup that I did
> wrong the first time.

The GIDE seems to work.  It appears to be FDISK that is broken.
Given that, unless people had custom versions of FDISK I fail
to see how anyone set up a hard disk on a P112.

> It doesn't help that there are no docs for the thing other than whatever
> paper came with it.

Thus the reason for me searching places like this for help.  :-)

> Sanity check your software versions?  Mixing and matching variants can
> be problematic since there are several generations and several forks of
> the P112 and GIDE stuff; and there's at least one version of FORMAT
> that's reputed to have a serious bug.

No mix or match.  Just using the images provided on the CD that
came with it.  FORMAT works OK for 3.5" disks.  I have had no
luck trying to FORMAT 5.25" or 8" floppies.  And I can't even
get that far on a hard disk.


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