[Coco] Re: [Color Computer] Older Floppy Drives

[Gene Heskett]

On Monday 16 May 2005 18:33, Jan Vanden Bossche wrote:
>Hallo
>
>
>----- Original Message -----
>From: "Gene Heskett" <gene.heskett at verizon.net>
>
>> >TEAC Model FD-55GFR-541-U 5 1/4" Floppy Drive
>>
>> This last (TEAC) one is a 720k/1.2 drive, not really usable as a
>> primary drive on a coco/os9.  But when switched to 300 rpm, it
>> will make a great 720k drive, uses DSQD disks for best results.
>
>I've got 2 of those. How do I switch them to 300 rpm/720 KB
> operation ?
>
There's a jumper on the board, but I don't know the acronym for it at 
the moment.  Lemme see if I can find the manual again...

Mmm, did, but mine (all copies) are old enough that the 55F and 55G 
are treated as seperate models.  Apparently the next production run 
combined the pcb into a single board that could be used for either 
since the mechanics are identical.

Jumpers listed in my manuals are:
HS
DS0
DS1
HM
DS2
DS3
MX
in one row, and
UR
ML
IU
HL
SM
U0
U1
RE
in another row, and a final PM jumper that was off by itself.

So, if you have a jumper visible that isn't labeled as one of the 
above, it may well be the motor speed.  I believe that the later 
drives also had the ability to have this controlled from the 
interface, but I've not been exposed to the how is this actually 
done.

The last time I actually did this was not to a TEAC drive, but to a 
Mitsumi IIRC.  Its in my coc3's drive & psu tower, and a bear to 
remove and verify.  And no help for this instant problem.
Some of the later PC style controller chips has this as one of their 
options.
>> I've no experience with the others, sorry.
>
>Greetings from the TyRannoSaurus
>Jan-80
>
>
>Brought to you by the 6809, the 6803 and their cousins!
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>
>
>

-- 
Cheers, Gene
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