PinOut of DEC F11 Chips in a Professional 350

[Rob Jarratt]

Thanks Noel. According to the printset for the KDF11-A pin 23 is the RESET
signal, which would make it the 3rd pin from the right at the top right of
the CPU. The printset also showed a second chip with its RESET on pin 23 and
I have confirmed that E151 and E152 have pin 23 tied together. So I am
pretty confident that this is indeed the RESET.

I have been tracing the source of the RESET, because as I have said it is
oscillating, and it seems to go through a *lot* of logic, and I haven't
fully traced the source of the oscillation yet.

Regards

Rob

> -----Original Message-----
> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Noel
> Chiappa via cctalk
> Sent: 27 October 2018 02:56
> To: cctalk at classiccmp.org
> Cc: jnc at mercury.lcs.mit.edu
> Subject: Re: PinOut of DEC F11 Chips in a Professional 350
> 
>     > From: Rob Jarratt
> 
>     > The chips where I believe the RESET is oscillating on pin 23 have
been
>     > labelled E151 and E152 ... But I am not really sure if I have
>     > identified them and the pin correctly.
> 
> E151 is the main CPU chip:
> 
>   http://gunkies.org/wiki/F-11_chip_set
> 
> E152 is the KEF11-A floating point chip, and E150 is the KTF11-A memory
> management chip.
> 
> Pin 1 of E150 is definitely in the lower left corner (in the photo);
there's an
> indent on the left-hand side of the chip, for the usual DIP orientation.
> I'm pretty sure the other two have the same orientation.
> 
> 	Noel