[Coco] Help - CoCo emulator disk image formats...???

[Bert & Peggy Schneider]

Bob,

Thanks - I think I will contact the author.  I'm so close - it has to be
something simple.

Bert

-----Original Message-----
From: coco-bounces at maltedmedia.com [mailto:coco-bounces at maltedmedia.com]
On Behalf Of Robert Gault
Sent: Saturday, July 15, 2006 5:00 PM
To: CoCoList for Color Computer Enthusiasts
Subject: Re: [Coco] Help - CoCo emulator disk image formats...???

Bert & Peggy Schneider wrote:
> Bob,
> 
> Thanks for getting back.  Since your last note, I've tried a couple of
> things differently.
> 
> I installed the j version - which is the latest and greatest.
> 
> I've also tried the 96 tracks per inch.  It doesn't change anything.
> 
I have version i  which works with 96 TPI for 3.5" drives. I've no idea 
why that does not work for you and you should contact the author.

> By going to the j version, I have gone much further than before.  I
even
> formatted the floppy on the CoCo 3 first, before copying files to the
> floppy on the PC.
> 
> Which format should I use?

You should use the same format you intend for Write. It depends on the 
size of the image and whether the disk/image is Disk Basic or OS-9. On 
my system both the Format and the Write/Read should be 96TPI for 3.5" 
drives.

   Should I copy a .dsk or .img format?
> 
Does not make any difference to OmniFlop as it will Write a .dsk just 
fine. If you Read a disk with OmniFlop, whatever the image file has for 
an extension, change it to .dsk or .os9 as required by the emulator to 
be used.

> Bert

!!!!!!!!!*************!!!!!!!!!!!
One major caveat for all PC programs that format Coco disks. By in large

they all use a zero skip factor. Meaning each sector on the disk follows

in sequential order. This is not how a Coco disk is formatted and it can

significantly slow down disk I/O on a Coco.

The skip factor, to quote Tandy, works as follows.
"The computer reads or writes data to the disk one sector at a time. 
Between sector reads or writes, it does some processing.

The disk does not stop and wait for the computer to do this processing. 
It spins continuously.

...
To allow for this time differential, the computer sets a "skip factor" 
of 4 when it formats the disk."

OS-9 uses a smaller skip factor but there is one.

-- 
Coco mailing list
Coco at maltedmedia.com
http://five.pairlist.net/mailman/listinfo/coco