11 Nov
2018
11 Nov
'18
2:52 p.m.
-----Original Message-----
From: Tony Duell [mailto:ard.p850ug1 at gmail.com]
Sent: 11 November 2018 18:41
To: rob at jarratt.me.uk; Jarratt RMA <robert.jarratt at ntlworld.com>; General
Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
Subject: Re: Another IC I Can't Identify
On Sun, Nov 11, 2018 at 6:32 PM Rob Jarratt via cctalk
<cctalk at classiccmp.org> wrote:
Thanks for all the replies. If that is indeed what it is, then I still have not been able
to find the source of one of the signals that seems to be causing the Reset, every pin I
have found so far is an input, I have not found it connected to the output of anything yet
:-(
Regards
Rob
I am still working on the causes of a Reset on my Pro 350. One 8-pin
DIP chip that I have traced to is marked as follows:
9643TC-B1
F 8313
KOREA
It is very close to the F-11 chips at the bottom left and marked E135
in this picture
https://rjarratt.files.wordpress.com/2018/10/system-board-labelled.jpg
How about a Fairchild 9643TC dual TTL-MOS level shifter?
I found a datasheet with Google. The pinout seems to be :
1 : Input A
2 : Enable Input
3 : Input B
4 : Ground
5 : Output B
6 : Vcc2 (Output stage Vcc)
7 : Output A
8 : Vcc1 (Input stage Vcc, normally +5V)
