Replacing drives on classic systems was Wild-hair floppy drive question
cctalk at randy482.com
Mon Jun 13 21:01:09 CDT 2005
When replacing drives in classic systems there are some things to keep in
Newer drives are mainly compatible but not 100%.
Today we can go to the local store buy a drive (floppy to hard drive) plug
it in and expect it to just work. Things have changed.
To install a drive in a classic computer it is easiest with documentation.
With newer drives study the use of "modified" pins on 34 pin connector (2,
10, 12, 14, 16, and 34 especially).
I have some useful information on disks and disk drives on my website.
Pin 2 - 8" drives low to reduce write current for some tracks (but not
all) - PC drives high to reduce write current for the entire drive and
optionally change rotational speed.
Pin 10 - Classic 5.25" DS0 - PC motor on for drive A on controller side,
unused on drive side (part of cable twist).
Pin 12 - Classic 5.25" DS1 - PC DS for drive A (part of twist).
Pin 14 - Classic 5.25" DS2 - PC DS for drive B (part of twist).
Pin 16 - Classic 5.25" Motor on - PC motor on for drive B for controller
always motor on for drive (part of cable twist).
Pin 34 - Sometimes ready sometimes disk change, either verify or cut.
There are lots of other options to take into account all I can say is don't
expect to add a drive to a classic system and expect it to just work. Often
it takes a lot of head scratching and reading. Please note I did not
mention that there are lots of jumperable optoins on many systems.
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