Gottlieb U2U3 Adapter
Gottlieb MPU adapter for combining U2&U3 roms
This is a project back from 2016.
The adapter is very similar to the Gottlieb 80B 'Piggyback' and can be used as a direct replacement for the original adapter on system 80B MPUs.
On an 80 or 80A board it is also possible to combine old U2&U3 2332 roms into one more 'modern' 2764 EPROM.Just combine the original roms with a DOS copy command: "copy /b u1.bin + u2.bin u2u3.bin" and burn u2u3.bin to the 2764 EPROM.
In addition to the PCB you need the (programmed) 2764 Eprom for your game, two adapter strips, a 74LS04 TTL IC and an IC socket for the 2764 Eprom.
the adapter PCB
adapter strip Installation on a Gottlieb 80 or 80A MPU
Desolder the original U2 & U3 roms and place an IC socket to the postion of U3. The adapter will be placed into the socket at the original location of 'U3'.
No further board modification needed!
Prototype placed on a Gottlieb System80 MPU