[Coco] Floppy Controller available.

[Stephen H. Fischer]

Hi,

When I put the RS ROM in the J&M controller, all the disks I had read the 
same.

J&M had some extra commands, and the ROM addresses were different.

It used a Synertek 5 Volt only floppy controller, I stopped by them on a 
trip and the same person who sold me the controller in Palo Alto said, I 
heard that noise before and replaced the floppy controller chip. They 
purchased ALL of the floppy controller chips remaining at the end of 
Synertek.

I got a copy of the document as to how to make it CoCo 3 compatible at that 
time. They may have shown me a running CoCo 3, the display was just so much 
sharper anyway.

SHF

----- Original Message ----- 
From: "Arthur Flexser" <flexser at fiu.edu>
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Sent: Tuesday, April 16, 2013 8:55 PM
Subject: Re: [Coco] Floppy Controller available.


> It doesn't matter which of the index holes was originally the "real"
> one when the disk was formatted.  The CoCo uses the index hole ONLY in
> formatting, not in reading or writing to the disk, so whoever inherits
> this stuff doesn't need to worry about this in trying to read whatever
> is on the disks.
>
> Also, if I'm remembering right, didn't J&M's JDOS have an alternate
> disk format that broke the storage down into smaller units than a
> granule?  Maybe the unreadable disks were written using that format
> and can only be read under JDOS?  Or perhaps they are normal RSDOS
> disks and, if JDOS is in the controller, they can't be read because
> JDOS expects its own format?
>
> Art