No Longer Available Williams System 4 MPU

[BrianSoton]

I have 2, both taken from working machines.

£60 posted each

 

[stevebm1]

what's the difference between a system 4 and system 6 board,I though you could just swap roms?

 

[BrianSoton]

Me too but not an expert I’m afraid, you’d need to check Clay’s Guide

 

[BrianSoton]

Bump

 

[Jay Walker]

The difference between Level 4 and Level 6 boards? The main technical improvement between the two is that Lev. 6 games have a 'Memory Protect' switch operated by the coin door, with the Cpu board altered to accommodate it. There are a few crossover games (e.g. Gorgar, Laser Ball) that can use L4 boards with enough sockets as a replacement, accepting the lack of the Memory Protect facility. AIUI, it was brought in to prevent the settings being altered with the door closed, f'r instance in the event of battery failure.

 

[stevebm1]

thanks for clearing that up Jay