[PX8, etc ROM carriers]
Interesting tidbit that they were used in those other
machines, I didn't know
that.
About 20 years ago, back when Maplin (UK Electronic shop) actually sold
enough components to design something with, and when ZX81s were still in
use, I designed an interface for the school's 81 (8 bit ADC, digital I/O
lines). I used some connectors that Maplin called 'Multicon', but which
were actually Molex 0.062" things.
Anyway, Maplin were out of stock, and didn't know when they'd get any
more. I actually called Molex to ask if there were any other distributors
for said connectors, and they gave me some names and sent me their
catalog. I am sure those carriers (and the sockets they fit into) were in
there. In fact I think I asked many of the distributors if they carried
them. None did from what I remember.
I wonder if they were almost a standard at one time.
2) Is the PX4 technical manual on the net
anywhere (I've found the PX8
one already).
Do you have a link handy?
It's on Bitsavers (
http://www.bitsavers.org/, but use one of the listed
mirror sites if you can). Go to the document archive, it's in the 'epson'
directory. Warning: It's big!
The thing I need most at the moment is the pinout
of the cartridge
connector. I have a 3rd party 512K (!) RAMdisk module there which doesn't
seem to work.
First I've heard of any third-party stuff for that machine as well.
I don't know the origins. It was in the machine when I bought it at a
radio rally (hamfest) about 15 years ago. From what I rmember, the seller
had a pile of them, I think all the same spec.
In my PX4 are 2 EPROMs. One is the standard utilities ROM (PIP, STAT,
CONFIG, etc). The other seems to be the drivers for this RAMdisk. It is
in one of the carriers, but it's a hand-labelled ROM and looks to have
been crimped into the carrier by hand, not with one of the press tools.
Maybe a prototype or a low-volume product.
-tony