This is a Kernal Adapter/Switch for the Commodore C64, ASSY250469 (short board). Since the BASIC is stored in the same ROM, some circuit is required to allow a stable access to BASIC, while the Kernal can be selected. The kernal selection can be configured with jumpers, a switch or even with a micro controller. +5V are provided on the pin header for this purpose.
This development was inspired by Adrian Black's youtube video How-To: C64 Arduino based Restore Key/Four Kernal Switcher/Hard Reset
Rev. 2 provides an optional pin heaer with the address bit A5 and A8 for stereo SID applications
The component prices of BOM v0.0 were summed up. The total is 4.88€, which does not include any shipping fees.