UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Timbucus · 5th May 2020, 10:42 pm

Also I am also not sure now that IC11 is a 74C04 as you suggest as you can clearly see two patch wires from the marked W and R and I think they snake across the board to use pins 1 and 2 which would be the first Hex inverter on a 7404... Still you can do the same with shorting out the two inputs to a NAND gate so that is also a valid solution and means that IC2 and IC11 - stay in their own areas - the diagram I posted above began to reflect that element of doubt.

Edit - actually that is more likely that IC11 is a 74C00 and the W and R wires running from Pin 1 and 2 on the CPU are going to pin 1 and 2 on IC11 which are the inputs to a NAND gate in that chip... so ignore the above...

5th May 2020, 10:42 pm	#41
Timbucus Octode Join Date: Mar 2019 Location: Barry, Vale of Glamorgan, Wales, UK. Posts: 1,364	Re: Good review of SC/MP. Also I am also not sure now that IC11 is a 74C04 as you suggest as you can clearly see two patch wires from the marked W and R and I think they snake across the board to use pins 1 and 2 which would be the first Hex inverter on a 7404... Still you can do the same with shorting out the two inputs to a NAND gate so that is also a valid solution and means that IC2 and IC11 - stay in their own areas - the diagram I posted above began to reflect that element of doubt. Edit - actually that is more likely that IC11 is a 74C00 and the W and R wires running from Pin 1 and 2 on the CPU are going to pin 1 and 2 on IC11 which are the inputs to a NAND gate in that chip... so ignore the above... Last edited by Timbucus; 5th May 2020 at 11:06 pm.