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-boun...@classiccmp.org] On Behalf Of Noel > Chiappa via cctalk > Sent: 27 October 2018 02:56 > To: cctalk@classiccmp.org > Cc: j...@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
