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:
| Shop | Link |
|---|---|
| RetroRevivalShop | http://retrorevivalshop.co.uk/index.php?main_page=product_info&cPath=5&products_id=31 |
| Retroleum | https://www.retroleum.co.uk/zx-spectrum-chips |
Using a multimeter check the traces for IC26, the the diagram below for chip pin position
| Pin | Traces to | Voltage |
|---|---|---|
| 1 | IC26 Pin 1/ IC23 Pin 8 | |
| 2 | IC2 Pin 38 | |
| 3 | IC2 Pin 31 / IC4 Pin 3 | |
| 4 | Upper Ram (IC15-22) Pin 6 | |
| 5 | IC2 Pin 37 | |
| 6 | IC4 Pin 6 | |
| 7 | Upper Ram (IC15-22) Pin 5 | |
| 8 | IC1 Pin 40 / IC3 Pin 8 / IC4 Pin 8 | |
| 9 | Upper Ram (IC15-22) Pin 9 | |
| 10 | 4 Right (jumpers at top of board) | |
| 11 | TI L H Left (jumpers at top of board) | |
| 12 | Upper Ram (IC15-22) Pin 7 | |
| 13 | IC2 Pin 32 | |
| 14 | IC2 Pin 39 | |
| 15 | Voltage regulator middle leg | |
| 16 | Voltage regulator top leg |