I have managed to get 2 PC type drives working in a 9122C they are two
different versions of the YE Data YD-702D. The important thing is the
drive needs to provide a ready signal, diskette change and density.
Most drives provide the last two but do not have a ready signal. You
also need to leave pin 1 unconnected this is a signal from the
controller to reset the diskette changed signal. One of the drive the
YD-702D-6037 can also be altered by moving jumpers to get power from the
cable. The other a YD-702D-6537D does not and it unfortunately seems to
be the more common drive. I changed the drives so that ready is on Pin
34, diskette change on pin 2 and density on pin 4, the same as the Sony
drive in the 9122C. I did encounter one problem where if I tried to CAT
a diskette it would always report that the diskette was changed or
missing and I recall encountering this previously, it may be related to
how the diskette changed signal gets reset. On most "standard" 3.5"
drives the diskette changed signal gets reset as soon as the drive is
selected and receives a step pulse. On the Sony drives used in the 9122C
reset the diskette changed signal by a pulse on pin 1 from the
controller. What I think is happening is when media is changed, the
controller thinks it does not have to move the head so the diskette
changed never gets reset so the controller continues to think the
diskette has been changed, I will do more testing to verify. I thought
that booting with the drive empty provoked this but that is not the
case. I can post details of the modifications to the drives if anyone
is interested.
Paul.
On 2017-11-17 1:26 PM, Paul Berger wrote:
I just checked my 9122C I happen to have open and the interval between
index pulses is 199.66mS which would be 300 RPM, which is good news
for me I can now proceed with adapting a more common 1.44 drive to
replace my broken one.
Paul.
On 2017-11-17 1:04 PM, Eric Schlaepfer via cctalk wrote:
Check your email. How can you tell if it uses a 600 RPM mechanism or
not?
On Thu, Nov 16, 2017 at 3:17 AM, Eric Smith <space...@gmail.com> wrote:
Hi Eric,
It's not urgent, but when you have a chance, could you dump the 9122C
ROM(s) and take high resolution photos of the controller board?
Since it does HD, I suspect it probably does not use a 600 RPM
mechanism.
Thanks!
Best regards,
Eric
