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MPI B92 is interesting. It's 4 or 5 revs beyond the B-51 logic board and almost all the IC's and many of the traces are different. There's definitely a 10 slot header for the data separator daughter board to which pins need to be soldered. Also, it's single-sided. The mechanicals are nearly identica...

Hi Grant,

Thanks for sharing these instructions. I think they apply to the MPI-52, not the MPI-92. Would you know if the logic boards for the two models are similar? The 92 is an 80 track. The 52 is a 40 track, I think. Tom

Has anyone found a copy of the service manual for the MPI (Micro Peripherals Inc) B-92 floppy drive? I'm going to see if I can use it with my 600/610 setup in place of the B-51 that originally came with my C1PMF. First, I need to see if there's an attachment point for the MPI data separator daughter...

Danny,

We must have crossed paths at some point, at user group meetings. I certainly remember Hal -- he modified my C1P so that I could interface it with a modem and some type of thermal electrostatic line printer. Thanks for bringing up good memories.

Tom

Hi Grant,

All the indications are a problem with the MPI logic board or sensors or maybe the ribbon cable. There are no breaks or frayed edges but there are some heavy duty bends at a few points along the cable. Tom

I've been careful not to switch cables while the power is on, nor to move the drive mechanism in any way. I don't think it's bad memory: have tested this on two sets of 600/610 boards with memory that checks out okay. And I've been loading the boot file through a serial connection at 300 baud. I kee...

In connection with an effort to bring a C1PMF fully back to life, I'm investigating options for replacing/repairing the mechanicals and sensors on a MPI B-51. I've determined that the Atari used the MPI B-51 mechanicals and sensors only for its 810 drive (1980's vintage). There is an outfit that sel...

bsudbrink, I lubricated the drive mechanism and positioned the r/w head as suggested. Sure enough, when I hit D, the r/w assembly moves to track zero. A sign of life but I'm left with two inter-related issues: * (1) The head moves only when I have the ribbon cable from the 610 to the drive logic boa...

I did try ini 25 with no luck. The stepper motor seems dead -- or nearly so. Once in a while, it will twitch when I try to boot to the drive. I swapped in my spare 610 board just to double check and nothing changed. I'll try to write a track directly without initializing the disk as you suggest. So ...

I think I've hit a dead-end getting my MPI B-51 to work. The voltages going to the PCB and drive motors are good. I can verify that the drive is receiving signals from the 610. All connections between the drive logic board and various motors and sensor are correct. The spindle is turning at 300RPM. ...