[Coco] Determining OS-9 Floppy Type

[Stephen H. Fischer]

Hi,

When they got to 80 Tracks on 5 1/4" floppies the double head capability was 
well known and as the mission was to put as much as possible on a single 
diskette, a single head would never been considered.

Having said that, I have many single sided 80 Track OS-9 disks.

This was done for many reasons:

a) Booting a double sided OS-9 system disk was not possible initially. (I 
got my two TEAC 80T 2S drives as soon as they were available, they did not 
become popular.)

b) I used SDISK3 which had the 80T 2S support first before the more standard 
drivers did. (D.P. Johnson)

c) A 80T 1S disk holds the same amount of data as a 40T 2S disk, it was 
useful in the early steps of creating disks for a friend who had only 40T 2S 
disks. I never had any problem creating 40T 2S disks for him in my 80T 2S 
drives as I always bulk erased the disk before SFORMATing a disk for him.

d) Jeff's emulator had an error with reading double sided disks but I could 
read single sided disks just fine. Now fixed in the 6309 version.

My current floppy configuratation is one 80T 2S 5 - 1/4" drive and one  80T 
2S 3.5" drive. They can be interchanged (/d0 to /d1, /d1 to /d0) just by 
flipping a switch.

My descriptors are set up for 80T 2S on both /d0 and /d1. OS-9 now can read 
any formatted disk just by reading LSN0.

ALL my disks have the correct LSN0 values so this is possible.

Stephen H. Fischer


----- Original Message ----- 
From: "George's Coco Address" <yahoo at dvdplayersonly.com>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Sunday, May 27, 2007 11:23 AM
Subject: Re: [Coco] Determining OS-9 Floppy Type



> Wow! Was there an 80 track single sided disk drive? I never heard of it. I 
> suppose there are other combinations that could be confusing also.
> Hadn't thought of that.
>
>
> George