[Coco] [Color Computer] Re: 3.5" drives on coco 3

[Phill Harvey-Smith]

Carlos Bragatto wrote:
> Hey guys, completely unrelated, but I've sucessfully adapted modern 3.5"
> disk drives to run on Amstrad CPC, replacing the internal 3 (yeah, three,
> not three and a half) inches disk drive.

Yep, for some reason Amstrad had a fetish for 3" drives....used them on 
the CPC and PCW ranges as well as the (Sinclair) Spectrum +3

> Since it uses a standard FDC controller, the same one used on IBM XTs, I can
> use it like a 3" drive, 160k per side.

The gotya with the CPC/PCW/+3 machines (and the Amiga IIRC), is that 
they need a ready signal on pin 34 of the drive, which most moden drives 
do not supply, though often it seems you can get away with just 
grounding the line....

The CoCo/Dragon and most other retro machines that I have used do not 
seem to have this problem, though I do seem to remember something odd 
about Atari STs....

> The original 3" disk can be turned over so data can be r/w on both sides,
> and since this cannot be done on a 3.5" disk, you can add a "side select
> switch" and manually choose which side of the disk you want to write to. I
> followed this guide:

Yeah, and I believe there are programs for both the CPC and the +3 that 
allow you to format the entire 80 tracks, the +3's rom can also cope 
with double sided disks too, which I believe the CPC's cant.

Anyway....

Cheers.

Phill.

-- 
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !

"You can twist perceptions, but reality won't budge" -- Rush.