22 Mar
2002
22 Mar
'02
3:43 p.m.
I guess I'm having a "senior moment" but I don't remember the 4118 at
all,
though I definitely remember that there was such a thing. Mostek made a
couple of pseudo-static RAM parts that were on a ~2716-compatible pinout. Was
that one of them? I've got some 1K- and 2K- byte parts from those days but I
don't remember the numbers right offhand.
Perhaps someone could refresh my recollection.
Dick
----- Original Message -----
From: "Glen Goodwin" <acme_ent(a)bellsouth.net>
To: <classiccmp(a)classiccmp.org>
Sent: Friday, March 22, 2002 9:51 PM
Subject: ZX81 and 6116
check,
From: Pete
Turnbull <pete(a)dunnington.u-net.com>
Pete,
what modifications to the board are required in order to use a
6116?
I don't have either the service manual or my ZX81 handy, so I can't but as far as I remember, just remove the 4118
and replace with a 6116.
I'll check it out.
There might be a wire link to change (if so,
it's obvious) but I don't
remember having to do that.
There are no links on the board for different memory configurations.
It is good practice to fit a socket, though.
I always do when I replace an unsocketed IC on a ZX81.
A few ZX81's had a pair of 2114's
instead of the normal 4118, which were
in short supply at one time, but the same principle applies (the PCB is
the
same).
I read that using the 2114s saved Uncle Sir Clive 25p per unit. I've also
noticed that on the earlier boards all the ICs were socketed, but the later
ones were spotty, socket-wise. Typical Sinclair chintziness.
Glen
0/0