ZX Spectrum IC4
The IC4, like the IC3 – 74LS157N – is for the lower 16K of RAM, a bad chip or trace will usually manifest itself as corrupt graphics on the screen
A modern replacement can be found here:
Shop | Link |
---|---|
RetroRevivalShop | https://retrorevivalshop.co.uk/index.php?main_page=product_info&products_id=35 |
Retroleum | https://www.retroleum.co.uk/zx-spectrum-chips |
Using a multimeter check the traces for IC4, the the diagram below for chip pin position
Pin | Traces to | Voltage |
---|---|---|
1 | IC3 Pin 1 | |
2 | IC2 Pin 38 | |
3 | IC26 Pin 3 | |
4 | R18 Right | |
5 | IC26 Pin 5 | |
6 | IC26 Pin 6 | |
7 | R17 Right | |
8 | IC26 Pin 8 | |
9 | ||
10 | ||
11 | ||
12 | R19 Right | |
13 | IC26 Pin 13 | |
14 | IC26 Pin 14 | |
15 | IC26 Pin 15 | |
16 | IC26 Pin 16 |