ROMY is a small add-on PCB that enables Amiga 3000 / 4000 computers to use 1MB (or larger) Kickstart chips.
This project aims at iterating and improving the existing Romy designs.
In the hardware directory you will find the kicad schematics and PCB for the
latest versions of "my" ROMY:
This version was the first one I made. It fits snugly on top of a soldered-down Fat Gary. The GAL is a PLCC-28 ATF22V10C type. This design is the most similar to the original Romy.
This version is a revamp of the A3000 Romy. On the A3000 Fat Gary is socketed using a through-hole PLCC-84 socket. Previous designs have required to unsolder the socket, and solder a PCB between a socket and the mainboard, in some variants adding a capacitor on the bottom of the mainboard.
This new design uses a PLCC-28 ATF22V10C GAL instead of the DIP version on older Amiga 3000 designs. This is convenient because it lets you exchange GALs between the A3000 and A4000 version.
To prevent having to solder on the A3000 board, I am using PLCC plugs (such as the APW9328 from adapt-plus.com).
Now this gets exciting. PLCC parts are annoying to solder and fairly big. So I skipped DIP and SOIC and went straight to the TSOP version of the ATF22V10C. The small footprint of this part allows to create a single board for Amiga 3000 and Amiga 4000 machines.
- If you want to build an A4000 Romy with this design, put a PLCC84 socket on the back of the PCB, and a capacitor and GAL on the front.
- To build the A3000 version, instead solder a PLCC-84 socket on the front of the PCB, and solder the cap and GAL on the bottom. Then solder the PLCC plug over the components.
This design is barely wider than Fat Gary itself and adds the same functionality as the other ROMYs with minimal impact.
The logic directory contains the contents for the GAL.
Look in the software directory for a bunch of scripts to create a nice 1MB ROM
image for you.
There's also a small program to create parametrized PLCC plug footprints for KiCAD.
Romy has been developed in the past by speedgeek and Cosmos. Anton Gale kept the designs alive on OSHPark. Thanks to John Floren for an amazing Amiga 3000, and to Acill for patiently teaching soldering skills to firmware engineers like me and for building an awesome community.