the stream

reverse engineering the Newton MessagePad ROM card

Alexander Bochmann Tuesday 07 of March, 2017
Here, with Eagle schematics.

Matthias Melcher wrote:
Anyway, wouldn't it be fantastic to create a souped-up ROM board? 8MB Flash and 8MB NewtonOS, also in Flash, being able to patch it, fix it, extend it, have fun. Maybe have even more that 16MB if that is possible. Is it possible? How can we find out?

An early draft of the licensee information for this ROM card exists, but it is not detailed enough to build such a card. Before starting a patch wire solution, I wanted to know how the original board worked, and then fill in the missing information in that draft.

Well, I went all the way and reverse engineered the entire ROM board. Here are my findings.

The article also reminded me of this old post by Landon Dyer, which explains how they came up with the ROM-patching idea...

(Via tedu's inks.)