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
Received on Fri Feb 21 2003 - 06:50:01 GMT