From 62b98d1cdc8f1596fbc3dcca9476245097b62f6d Mon Sep 17 00:00:00 2001 From: Stas Date: Thu, 10 Sep 2020 22:26:04 +0200 Subject: [PATCH] add info on gal --- README.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/README.md b/README.md index 972c9ac..1422b27 100644 --- a/README.md +++ b/README.md @@ -4,6 +4,7 @@ This repo contains Kicad sources for a Static RAM expansion board for Sharp X68000 personal computer. +## 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. @@ -12,3 +13,7 @@ Board dimensions are taken from the [midori](https://github.com/tdaede/midiori) The board can support up to 8MB of memory and assumes you already have 2MB built in. If a fourth address line is routed, the board can support 1MB systems by masking half of the first memory chip. I have tested it on a X68000 Expert system. + +## GAL Equations + +You can compile `.pld` GAL equations using [GALasm](https://github.com/daveho/GALasm).