[Coco] Disk drive questions?

Gene Heskett gene.heskett at verizon.net
Wed Dec 3 20:40:00 EST 2003


On Wednesday 03 December 2003 18:24, Ray Watts wrote:
>Gene Heskett wrote:
>>>>Does this easy setup work through BASIC as well as OS9,
>>>>or is your system
>>>>OS9 only.  If a person has a set of two double-sided
>>>>5.25" drives now, can
>>>>one set be replaced with 3.5" drives and still work in
>>>>BASIC?
>>>
>>>I should have clarified that I am running with Basic and
>>>not OS-9.   Is this an issue?
>>>
>>>Jim
>>
>>It can be, because the disk format is carved in the eprom data,
>>whereas with os9 the descriptor can be played with, gaining access
>> to the other side of the disk etc.
>
>Gene,   Either I didn't understand the question, or I don't
> understand your reply.  DS/DD 5.25" drives and DS/DD 3.5" drives
> look identical to the CoCo and can be mixed and matched.  Under the
> DECB ROM, they will all look exactly the same and, under OS9, they
> will become whatever descriptor you give each one - in a range of
> 160k to 720k.  Am I looking at something cross-eyed?

No,  only ignoreing the fact that most 3.5" drives today are built 
first and foremost for the HD diskette.  Taping over the hole to make 
a DD diskette out of an HD diskette leads to poor, undersaturated 
recordings on the HD diskette that are lucky to last a week or so 
before the read error rate goes thru the roof.

Couple that with the fact that the last 3 of them I bought, would not 
allow a 250kilobaud data rate unless the diskette was a DD diskette.

So one needs a good supply of DD diskettes.  Unforch, they are a 
little like hens teeth, very very scarce.

-- 
Cheers, Gene
AMD K6-III at 500mhz 320M
Athlon1600XP at 1400mhz  512M
99.27% setiathome rank, not too shabby for a WV hillbilly
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Copyright 2003 by Maurice Eugene Heskett, all rights reserved.




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