Another IC I Can't Identify

[Rob Jarratt]

> -----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:
> >
> > 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)
> 


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