Can anyone tell me anything about the Epson BM5 floppy drive unit?
Perhaps a little description will help.
Physcially it's about the size of an Epson TF20 and has one
vertically-mounted half-height floppy drive on the front, along with a
power LED. On the back are the usual mains connector and switch and a
DB25 socket.
The unit splits into 3 main sections, PUS, controller and drive
The PSU consists of a mains transformer and a PCB cotnaining an STK7561
hybrid chip. It claims to give out 5V at 2A and 12V at 3A. I guess
there's nothing to add about that.
The controller claims to be a 'Rabbit Board'. The main chips are a Z80A,
24K of SRAM, 8K of EPROM, an 8237 DMA chip and a 7261, which seems to be
a _hard_ drive controller. And of course a lot of TTL glue. The DB25
socket is fixed to this board, it's clearly a TTL level parallel
intefave, possibly SCSI-like.
The drive links to the cotnroller by a pair of ribbon cables, 1 20 way
and 1 34 way. I'm seriously suspecting an ST506/ST412 interface -- yes,
on a floppy drive.
The drive is Hitachi FDD541. The mechancial side looks conventional, a
stepper motor postiioned (it desont _seem_ to be servo-trackedm, although
I guess it could micro-step). Spindle motor, etc seem normal to, there is
a head-load solenoid. The disks are clearly of the normal 5.25" form
factor, but I suspect of a much higher coercivity.
There's a logic board fixed to the drive, full of ICs I've never heard
off, including a 637B01X0P (Microcontroller?), and an ASIC in a PGA
opackage). The contorller interface really does look like ST506/412.
Anyone got any ideas? What was it used with, what is the host interface?
-tony
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