X68000 4MB Memory Upgrade Gals Panic v1.2.

This expansion board will add 4MB of system ram to your X68000 computer bringing it to a total of 6MB. Tested on X68K Ace HD but will work on all X68000’s with an open expansion slot. You must have an initial 1MB upgrade installed to use this upgrade. Early X68k's shipped with 1MB so make sure you have 2MB installed if you want to use this upgrade.

This board has 2 x 2MB 45ns SRAM’s on board with the option to add 2 additional ram. The current configuration will give you a total of 6MB which is enough to play all games which have extended memory requirements.

This board has 6 buffers which provide 2000 volt static protection. These buffers will protect the SRAM’s from static due to physical handling as CMOS SRAM are quite sensitive to electrostatic charges.

The 10ns GAL controller is programmed to allow user configurable memory settings if you choose to add more ram to this board at a later time, simply close the selection jumper near that PAL to select the memory you’ve added. Otherwise it is already configured to work correctly with the ram installed.

The combination of 10ns GAL and 45ns SRAM allows for up to 66MHZ memory access however I don’t have a machine fast enough to test that .

All testing was done using Memtesf68k for 8hrs to ensure no defects prior to shipping.