[Coco] Disk drive questions?

[Willard Goosey]

>X-Original-To: coco at lists5.maltedmedia.com
>From: <jimcox at miba51.com>
>Date: Tue, 02 Dec 2003 23:53:16 -0800

>I'd also like to ask again, how easy is it to drop a 3.5" 
>drive into a system.  I know I have the answer some where 
>in the thousands of emails I have saved, but I thought I'd 
>save time and ask here.  Any pointers?

Pretty trivial in my experience.  You need the obvious stuff, a floppy
cable with no twists, and an un-used connector, power adaptor cable,
and probably drive mount adaptors.  You probably want a drive with all
four addresses selectable, and you (apparenty) MUST have one with a
jumper selectable DC/SR setting, and it must be set to SR. 

Under OS-9, the d2 80 track, double sided descriptor is perfect for a
3.5" drive.  DECB requires help to know about anything but 160K disks.

In my experience, Tandy drive boxes are fine with two drives, but
three pushes the power supply to its limits.  Beware.

I've had a 720K 3.5" drive on my coco for years.  It recently died and
now there's a 1.44" 3.5" drive in its spot, but I'm suspicious of it.

>I know that someone has said that the maximum number of 
>drives in a system is 3, though in the manual, it says the 
>maximum drive number is 3, so if you start with 0, my 
>logic says you can have 4 drives total.  

Tandy wired things weirdly, such that drive 3 (starting from 0) can't
be addressed.  Hard-core CoCoists will point out that Tandy's weird
wiring means more than 4 single-sided drives can be used, IIRC.

>Is it possible to have two different drive controllers in an MPI and
>toggle between them?

Apparently the standard thing to do is modify one to use a different
address base.  Normally this is only done if you have one of the
original FD-500 controllers.  The FD-500 can be hacked to support HD
drives (1.2 and 1.44M).  

>Jim
>
>PS: Anyone heard from Carl Boll lately?

Yeah, he's around.  

Willard
-- 
Willard Goosey  goosey at sdc.org
Socorro, New Mexico, USA
"I've never been to Contempt!  Isn't that somewhere in New Mexico?"
   --- Yacko