https://github.com/stas2k/galspanic
X68000 RAM Expansion
https://github.com/stas2k/galspanic
gal galasm kicad ram retro sram x68000
Last synced: 5 months ago
JSON representation
X68000 RAM Expansion
- Host: GitHub
- URL: https://github.com/stas2k/galspanic
- Owner: stas2k
- License: mit
- Created: 2020-09-10T20:24:41.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2022-03-18T08:50:21.000Z (over 4 years ago)
- Last Synced: 2023-03-10T06:41:27.602Z (over 3 years ago)
- Topics: gal, galasm, kicad, ram, retro, sram, x68000
- Homepage:
- Size: 1.44 MB
- Stars: 24
- Watchers: 7
- Forks: 8
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# GALSPanic - X68000 SRAM Expansion
This repo contains Kicad sources for a Static RAM expansion board for Sharp X68000 personal computer.
Please use latest git version of kicad to open the project, or version >6.0 once it gets released.
## Design
The expansion is implemented using 2MB static RAM chips to make the design simpler.
Address decoder is implemented using a ATF22V10 GAL chip. Source code for it is available in `gal/` directory.
Board dimensions are taken from the [midiori](https://github.com/tdaede/midiori) project.
The board can support up to 10MB of memory and assumes you already have 2MB built in.
A fourth address line is routed and the board can support 1MB systems by masking half of the first memory chip. However, the GAL equations are not written for this case. Let me know if you have such a system.
## Compatibility
Following systems have been reported to work:
- Super
- Expert
- ACE
- XVI
- Pro
- 68030
## GAL Equations
You can compile `.pld` GAL equations using [GALasm](https://github.com/daveho/GALasm).
## Board production
I use JLCPCB with the following options:
* PCB Thickness: 1.6
* Surface Finish: ENIG-RoHS
* Gold Fingers: Yes
* 45°finger chamfered: Yes