The only difference between the 2016 and the 6116, is tha the 6116 is CMOS,
while the 2016 is NMOS. That's not much difference.
Dick
----- Original Message -----
From: "Tony Duell" <ard_at_p850ug1.demon.co.uk>
To: <classiccmp_at_classiccmp.org>
Sent: Friday, March 29, 2002 2:12 PM
Subject: Re: ZX81 and 6116
> >
> > > So, fit L2 if you install a 6116 (A10 on pin 19). Fit L1 if you install
a
> >
> > > 4118 (I am not sure what pin 19 is, I can't find a 4118 data sheet, but
> > > at least one schematic I have calls it 'E', presumably an active high
> > > enable signal). Fit either or no links if you install 2 * 2114s. Never
> > > fit both links, or you'll short A10 to the +5V rail.
> >
> > Today I checked out about two dozen ZX81/TS1000s. They've been piling up
> > in a box and today I finally got to them. Here's what I found:
> >
> > All of the 1K boards had two 2114s and no jumper installed.
>
> As did my PCB. If you use 2114s, L1/L2 makes no difference (it's not
> connected to these chips at all). Might as well save 1cm of wire and a
> bit of solder :-)
>
> > All but one of the 2K boards had a single 2016 and L2 was installed.
> > One 2K board had a 6116 and L2 was installed. The board was operational
> > and appeared unmodified.
> > I replaced a socketed 2016 on a working board with the 6116 pulled from
the
> > above-mentioned board,
> > and the board still worked.
>
> The 2016 and 6116 are essentially the same chip, made by different
> manufacturers. There are other chips with other numbers that are
> essentially equivanet too. All are 2K * 8 static RAMs, pinout like a 2716
> EPROM with WE/ on pin 21. I am not suprised that they are interchangeable
> in the ZX81.
>
> >
> > So I think it's safe to say that L2 is required for a single-RAM-chip
> > board, and that a 6116 is a drop-in replacement for a 2016.
>
> The first part is a false conclusion. It's safe to say that L2 is needed
> for a single-chip _2K_ machine (using a 6116 or similar), which is what
> we've been saying all along. For a single-chip 1K machine (using a
> 4118), you use L1. You've not seen one of those boards, so you've not
> seen a machine with L1 fitted.
>
> -tony
>
>
Received on Fri Mar 29 2002 - 16:40:00 GMT