ZX Spectrum IC26

The IC26 is a 74LS157 Logic IC and can be replaced with a modern 74HCT157 Logic IC

A modern replacement can be found here:


Using a multimeter check the traces for IC26, the the diagram below for chip pin position

PinTraces toVoltage
1IC26 Pin 1/ IC23 Pin 8
2IC2 Pin 38
3IC2 Pin 31 / IC4 Pin 3
4Upper Ram (IC15-22) Pin 6
5IC2 Pin 37
6IC4 Pin 6
7Upper Ram (IC15-22) Pin 5
8IC1 Pin 40 / IC3 Pin 8 / IC4 Pin 8
9Upper Ram (IC15-22) Pin 9
104 Right (jumpers at top of board)
11TI L H Left (jumpers at top of board)
12Upper Ram (IC15-22) Pin 7
13IC2 Pin 32
14IC2 Pin 39
15Voltage regulator middle leg
16Voltage regulator top leg