Pinout/Replacement for Floppy Drive on HP 9133

[Tony Duell]

> 
> Hi,
> i have a HP 9133 floppy/hard drive unit where the floppy disk drive 
> doesn't operate anymore 
> (it returns read errors only) ...

If the heads are still good [1], these drives can often be repaired. I 
have unofficial schematics for the FC9 and FC16 logic boards in front of 
me...

> ... my first idea was to use a replacement drive from a 9122C/D unit, 
> but those, that i own,

Something is sort-of telling me that the 9122C/D is a high density unit. 
You might get the drive to work, you might not.

> have another pinout; the 9122 have only one 34 ? pin connector whereas 
> the 9133 floppy
> has two connectors, one standard power supply and another one having 
> 26 pins. Are those 
> somehow interchangeable ? 


I have pinouts for some of these connectors : 

The 26 pin one (FC9, FC16 PCB)

               1
   Motor On/ --o  o-- DS0/
Disk Chagne/ --o  o-- DS1/
Change Rst/  --o  o-- Step Direction/
         Gnd --o  o-- Step/
         Gnd --o  o-- Write Data/
         Gnd --o  o-- Write Gate/
         Gnd --o  o-- Head Load/
         Gnd --o  o-- Side Sel/
         Gnd --o  o-- Index/
         Gnd --o  o-- Track 00/
         Gnd --o  o-- Write Prot/
         Gnd --o  o-- Read Data/
         Gnd --o  o-- Ready/

Note that the DSn/ lines are binary encoded, not 1-of-n as on most other 
drives! This may not matter on a single-drive system.

  Power :
1  o-- +5V
   o-- Gnd 
   o-- Gnd 
   o-- +12V

I have a pinout for a version of the 34 pin connector, used on the 
MP=-F52W-50 drive (FC26 PCB). I don't know if this applies to your unit 
(this drive is a double-density unit), but here you are anyway.

                1
Change Reset/ --o  o-- Dosk Change/
          +5V --o  o-- LED/ 
          +5V --o  o-- DS3/
          +5V --o  o-- Index/
          +5V --o  o-- DS0/
          +5V --o  o-- DS1/
          Gnd --o  o-- DS2/
          Gnd --o  o-- Motor On/
          Gnd --o  o-- Step Dir/
          Gnd --o  o-- Step/
          Gnd --o  o-- Write Data/
          Gnd --o  o-- Write Gate/
          Gnd --o  o-- Track 00/
          Gnd --o  o-- Write Prot/
         +12V --o  o-- Read Data/
         +12V --o  o-- Side Sel/
         +12V --o  o-- Ready/

Note that there are _many_ soldered links on this PCB. You can swap round 
the functions of pins 2 and 34, you can make all the odd-numbered pins 
ground (and have a separate 4 pin power connector), add motorised eject 
(with the input on pin 1) etc, etc, etc. The pinout I've given 
corresponds to the drive used in the HP9114B.

Hope that is of some use to you

-tony