At 04:50 PM 2/21/03 +1000, Dr. Ido wrote:
At 09:38 PM 2/20/03, you wrote:
I just bought this
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=25399&item=250711253
7> off of E-bay. Obviously it's some kind of disk drive tester. I opened
it up and the entire front panel is hand wired but I also found a
commercail circuit board in it. On the board it says "MFD Checker II"
"Sony" "Made in Japan". Does anyone know anything about a MFD checker?
It
looks as though the circuit board was once the major part of another
machine and that they took the switches, displays and indicator lights off
of it and rerouted them to the front panel. However there are a few things
that they didn't put on the front panel; a 80 vs 70 track select (yeah 70
track), a drive select, a 300 vs 600 RPM select and a good number of test
points such as the write gate. However on the front panel you can now
select 2MHz, 1 MHz, 500kHz, 250kHz, 125kHz or 67.5kHz. Anybody know what
that's about? I'm guessing that it controls the bit frequency that's
written to the disk and th!
at it's used to test the disk coercivity. On
the original board you could
only select 1F or 2F. I should add that a 2nd baord as
also been added
into the case. It's a handwrapped vector board with 20 SSI ICs. I'm sure
that it's used to generate and select the extra frequencies and other as
yet unknown functions.
Anybody care to speculate?
Some of Sony's early 3.5" drives have a 26 pin connector and spin at 600
RPM. 70 track may be for the ~270K single sided 3.5" disk format (going
from memory here, correct me if I'm wrong).
You're right! I just went and dug out a manual for the HP 9121 and 9122 3.5"
floppy disk drives. The 9121 only has 70 tracks and is single sided. The 9122 has 80
tracks and is double sided. (Both are 600 RPM drives.) I had always thought they they were
all 80 tracks but it seems that the SS ones do indeed have 70 tracks.
If they weren't dealing with
any of those drives they'd have no reason to put
those controls on the
front panel.
True. But I'll change that!
Joe