[Coco] Disk drive question

gene heskett gheskett at wdtv.com
Tue Jan 17 22:30:09 EST 2012


On Tuesday, January 17, 2012 09:57:29 PM Bruce W. Calkins did opine:

> IIRC; the 1 and 2 meg memory systems needed OS-9 patched to boot.
> 
> Bruce W.
> 
That is a 1 byte patch in the init file IIRC, but I cannot quote the values 
off the top of my head.  Read, in the Nitros9 distribution, the init.asm 
file.

Humph, now I can't find it in my own repo.  Perhaps its been moved to krn1 
now?  No clue, but it was in init that this byte set the number of 8k pages 
of memory the system had 20 years ago.  Sorry, thought I could pull it up 
in 30 seconds.  But apparently its been moved sometime over 15 years back.
I did find a 19 year old version where byte $11 was $1F and I believe the 
fixed version was a $3F..  Bet on it?, nope, its been too long.

> =========================
> 
> ----- Original Message -----
> From: "Bill Pierce"
> 
> > My drive on a Coco 3 with 2meg memory, Fd-502/J&M controller,
> > with/without multipak. 1 40trk DS, 1 80trk DS (tried switching drives
> > and jumpers). The drive will read and load an OS-9 level 1 system
> > disk but when I try (several) Os-9 level 2 boot dsks, it either
> > freezes on "OS9 Boot" or starts to boot then resets back to DECB.
> > These boots are know to be good. It also errors on sector 0000 when
> > trying to format a disk. DECB seems to format fine but I have no DECB
> > disks handy to check. OS9 "backup" does not seem to work. lists
> > several errors as it formats, backup disks will not boot afterwards.
> > I've cleaned contacts and attempted to clean heads as well as I could
> > with a q-tip. I do bot have a 2nd coco to check for a bad coco. It
> > seems to be working fine. All commands work fine from the Level 1
> > boot.
> 
> --
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Cheers, Gene
-- 
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