[Coco] Read Coco floppies in my PC
Stephen H. Fischer
SFischer1 at Mindspring.com
Tue Mar 20 18:07:26 EDT 2012
My memory is very vague on the RETRIEVE problem, it may be when trying to
read side "B" (Back Side) it does not work with Jeff's RETRIEVE.
John's 6309 emulator help.txt says he enhanced the DSKINI and RETRIEVE
commands. Finding Jeff's side "B" problem was difficult I remember.
"OS9" is a better method of reading OS-9 disks.
Your results seem to ring a bell.
One thing that I always did was to use my Bulk Tape Eraser on the floppy if
it's contents was unknown!
"sector interleave" should not be a problem.
It might be that the Write Track commands produce different patterns
depending on PC or CoCo.
It has been way too many years since I looked at the (1776?) Write Track
command documentation and I never have looked at the same for the super I/O
chips for the PC, but I can accept that there are differences.
But thinking again (It has been > 30 years) the WRITE TRACK pattern is part
of the formatting program so DSKINI on the CoCo and PC (Jeff's and John's
code) may be writing different data.
If switching to John's utilities produces the same problem, then the Write
Track would be my prime suspect.
But then I remember no such problem reading my CoCo OS-9 formatted 3.5"
floppies being read using "OS9" which says it is a RETRIEVE problem. Try
John's to prove it.
I wonder if "OS9" might be using READ TRACK and RETRIEVE using READ SECTOR.
----- Original Message -----
From: "Chad H" <chadbh74 at hotmail.com>
To: "'CoCoList for Color Computer Enthusiasts'" <coco at maltedmedia.com>
Sent: Tuesday, March 20, 2012 2:22 PM
Subject: Re: [Coco] Read Coco floppies in my PC
This "problem" you are referring to, what is it?
I've always had a peculiar behavior between my CoCo Drives and my MS-DOS
system with DSKINI/RETRIEVE....
When I DSKINI a disk on the CoCo system, the RETRIEVE on the MS-DOS PC would
have errors reading it. No other problems have been encountered anywhere!
The same disks read/write fine in all my CoCo Drives. I tried swapping out
the 5.25" drive on the MS-DOS machine since I was using a 1.2MB drive. I
swapped it with 360K drives I had tested in my CoCo and still got same
What I have to do to get around the problem: DSKINI the disk with the
MS-DOS utility, then on the CoCo machine, BACKUP the disk I want to RETRIEVE
to the disk I have just DISKINI'd on the MS-DOS machine, then all is well.
My drive swapping should have eliminated the possibility of some drive being
out of alignment, speed specs, etc... I'm now suspecting a issue involving
the sector interleave used by the MS-DOS DSKINI & RETRIEVE. I tried
changing the parameters on the CoCo setup (i.e. DSKINI 0,3 or 0,4, etc.) to
see if RETRIEVE would then read the disk...Some parameters did seem to help,
but none were perfect.
So is this related to the known issue with Jeff's utilities?
More information about the Coco