24 Dec
2005
24 Dec
'05
12:55 a.m.
On Friday 23 December 2005 05:48 pm, Tony Duell wrote:
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!
Fetching the first chapter as I type this.
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.
The roms in mine seem to be hand-labeled too, I think there are three
altogether. There's a "wedge" on the machine, which I think has its own
battery besides the main one and I think there's also one other one inside
there someplace, it's been a *long* time since i peeked in there. I'd
collected a bit of info on those machines, but not nearly enough, and that
was before I had 'net access. I should probably do something with it one of
these days, get it going again. It was a fun little machine, and a nice
keyboard, that PX8...
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
[PX8, etc ROM carriers]
Hmm. Maybe some NOS exists someplace...
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? 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.