[Coco] Floppy drive/OS9 issue

[Stephen H. Fischer]

Hi,

The reverse works quite well as OS-9 was set up to do it.

If you have 80 Track 5 - 1/4" Double Sided drives and you have the Correct
Double Sided OS-9 device descriptor then OS-9 will look at the disk in the
drive and read Single or Double Sided OS-9 disks using either 40 or 80
tracks automatically. (Write only bulk erased disks at 40 tracks, and then
you must temporarily change the descriptor for formatting unless you are
using SDISK3's "sformat", standard CC3DISK's "format" does not have the same
option).

The DNS value on the disk must be correct!

I got a pair of  TEAC 80 track double sided drives when they were briefly
available.

They really made a CoCo Disk system usable.

Looking back at all the troubles I had with HD's and the time it took to
recover from problems, get set up and so on, I think that I did more with
just the floppy system.

When I replaced one of the 5 - 1/4" drives with a 3.5" drive I removed the
jumpers from both of the drives and using single pin connectors with the
wires connected to a front panel DPDT switch, I was able to interchange
"/D0" and "/D1" with just a switch throw. It is very nice but you must be
very aware what you are doing when you flip the switch.

As to the argument of what DNS value to use for 3.5 " disks, I use the same
value for both 5 - 1/4" and 3.5" disks so I can do a "BACKUP" from one to
another. (The 5 - 1/4" value is defined)

I also have identical copies of the OS-9 Boot / Run disk so if I need to
change to a different data disk size I can remove one  OS-9 Boot / Run disk,
flip the switch and put the other size OS-9 Boot / Run disk in. Again you
need to plan and be aware what you are doing.

As I was able to purchase a large number of 3.5" disks (One of the benefits
of living in Silicon Valley), I have copies of all my disks in both disk
sizes. I did that also for backup protection for bit rot. Now they are also
on CD's.

Floppies work quite well with OS-9 and two 80 Track Double Sided drives with
a ram disk (2 Meg Memory) make the C Compiler work quite well. It did for
me.

Stephen H. Fischer


----- Original Message ----- 
From: "Diego Barizo" <diegoba at adinet.com.uy>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Saturday, July 22, 2006 8:44 PM
Subject: Re: [Coco] Floppy drive/OS9 issue


> That's right. You need to load the correct device descriptor. If OS-9
> expects a single side drive, it won't read double sided disk, even if all
> the hardware is double sided.
>
> Diego