VIC-20 35k Memory expansion
PCB comes assembled with:
- Custom PCB (Colour will either be green or blue)
- IC1 – HY62256, 32Kb static RAM
- IC2 – HY6264, 8Kb static RAM
- IC3 – 74LS21
- RN1 – 8 way resistor network 10K
- SW1 – 8 way DIP switch
- IC Sockets
This is a custom PCB based on the schematic from Ruud Baltissen
http://www.baltissen.org/images/mem-exp.png
DIP Switch Settings:
- all off – Expansion Disabled
- 6 ON – 4607 free
- 6,7,8 ON – 6655 free
- 5 ON – 11775 free
- 4,5 ON – 19967 free
- 3,4,5 ON – 28159 free
- All ON – 35k
Warning: Do not plug/unplug any expansion card while the computer is on. You risk damaging the computer and the expansion card
The PCB connects to the expansion slot and by selecting various jumpers you can enable up to 35Kb of memory for your Commodore VIC-20.
At bootup the VIC-20 will only see 28k of memory. (So this is expected when booting up) The remainder of the memory is available and can be addressed via software.
