Need U.S. source for belt for Amstrad PCW8256 3" drive

From: Bill Dawson <whdawson_at_mlynk.com>
Date: Sun Jul 9 19:12:32 2000

-> > Hello all,
-> >
-> > Here's the dimensions of the needed belt:
-> >
-> > 72mm x 3mm x 0.5mm
-> >
-> > also acceptable:
-> >
-> > 71.0mm x 2.8mm x 0.6mm or 69-72mm x 3-4mm x 0.5-0.6mm
->
-> Have you tried a VCR spares company, or a TV/VCR repair shop? Most
such
-> places have an assortment of belts and might be able to provide
something
-> that's suitable. Buy a number of belts around (particularly smaller
than)
-> the size you think you want so as to get one that will fit.

This is what I'm going to try first. Thanks to all that suggested it.

-> > The rest of the story:
-> >
-> > I picked up an Amstrad PCW8256 today complete with
-> printer, original
->
-> Strange machine....

Yes, it is. But it runs rock solid.


-> Oddest thing is that there's no ROM/EPROM chip on the CPU board.

I noticed this.

-> There's a tiny bootstrap program (just enough to pull in the boot
-> sector of the floppy) in the gate array (the 80 pin surface mount
-> chip. IC101).

Yes, I had noticed this IC. Right in the center of the board.

-> I assume you know that the printer port will drive the original
printer
-> only, and that that printer only works with the PCW.

I figured there wasn't much in it, and the fact that all the options
could be set
from the main unit clued me in, especially the bail open sensor detect.

-> The printer
-> controller chip is an 8041/8042 on the main CPU board. The
electronics in
-> the printer is just the stepper motor drivers and head solenoid
drivers.
-> The signals on the ribbon cable from the computer to the printer are
-> basically the TTL-level drive signals for the motors and solenoids.

Thanks for the info. My unit doesn't have a ribbon cable, though. Just
a round
multi-conductor one.


-> You can increase the memory to 512K. Stick 8 256K*1 DRAMs (200ns or
-> better) in sockets IC112-IC119. Then move the like LK1 from position
A to
-> position B. This may be the first 2 positions of a DIP switch on
later
-> CPU boards -- turn off section 1 and turn on section 2.

Thanks for the tip. BTW,, this unit has a four position dip switch.
Right now, left
to right it is up-down-down-up.


-> When it came out in 1985(ish), it was already old-fashioned. A 4MHz
Z80A
-> and 256K of RAM, running CP/M.

Quite.

-> It sold very well though -- because it was
-> marketed as a word processor rather than a computer. Everything you
-> needed to do word processing was included (machine, printer,
software,
-> etc). So for people who didn't know what to buy, this was a machine
they
-> could take home, plug into the mains, and start typing on.

>From what I've read, it gave AMSTRAD quite a boost.


-> > After some poking around I decided to take the floppy drive out and
-> > check for head movement. This is when I discovered that the floppy
only
-> > spun when I pulled up on the pressure pad. At this time it started
-> > seeking, so seeing that the spindle is belt driven, I knew where
the
-> > problem was. I removed enough screws and connectors to get to the
old
->
-> This is a very common problem...
->
-> One word of warning. In one version of the drive (not the version
shown
-> in the service manual FWIW) there are mechanical sensor pins for disk
-> inserted and write protect. These love to fall out when you take the
-> PCB off the drive. And then you spend hours looking for them. So do
watch
-> out when you take it apart to put the real belt in.

I discovered the pin issue yesterday, when it fell out. It was no
problem figuring
out where it went. It just fits in a hole in the frame casting and
activates a
leaf switch on the PCB.

-> -tony


Thanks, Tony, for the info.

I understand a 3.5' drive can be put on this unit. Do you have any
information on this?

Anyone have an expansion interface or at least some info on the I/F
connector pins?

'til later,

Bill
Received on Sun Jul 09 2000 - 19:12:32 BST