Thanks Adrian,
I am not sure if the eprom programmer I have will do what you suggest, I don’t
have an Arduino but I do have a Raspberry Pi that I could probably employ in
testing the RAM. I may look into that.
I will look again at the writes. I have seen that the test pattern (0xAA) is
Another possible approach is to trigger the logic analyser on a write
access to that ram address, preferably with the probes on the ram itself.
Look at the resulting captures .. does it seem consistent with the code
and other accesses ?
On Sun, Oct 8, 2023 at 12:35 PM Adrian Godwin wrote:
>
Do you have one of those eprom programmers which also do device checks ?
They might do a check of the supposed faulty ram out of circuit. If you
don't have one you could probably write one for any convenient device you
have to hand such as an arduino. Exercising the ram with port writes will
be
> -Original Message-
> From: wrco...@wrcooke.net
> Sent: 08 October 2023 04:15
> To: r...@jarratt.me.uk; Rob Jarratt via cctalk
> Subject: Re: [cctalk] VT100: Failing 2114 Chip Replaced With One With The
> Same Fault
>
>
>
> > On 10/07/2023 5:35 PM CDT Rob Jarratt via cctalk
>
Here's my list of spare boards
Omnibus
MM8-E
M8320
M8650
M849
M8310
M8300
M8330
Unibus
RX11
G7273
M9970
M9047
M9714
QBUS
M7941
M8029 RXV21
M7504 DEQNA-M
M7850
M7546
M8186 KDF-11
M9400-YC
M7555 RQDX3
Rod Smallwood
