[NTLK] A new ROM board

Matthias Melcher m.melcher at robowerk.de
Wed Mar 16 13:17:00 PDT 2022

Hi Newts,

tl;dr : the ROM replacement board works and offers an additional 24MB of ROM-like storage for apps. Currently, the ROMs must be programmed externally, but I am working on a solution to make the boards reprogrammable by anyone.

It would be helpful to know if anyone is interested in buying any of these boards. Target cost is roughly 20 Euros plus shipping.

 - Matthias


Time for some geek stuff. I'll try to make it understandable for everyone. Sorry for any repeats.

The replacement ROM Cards that I built for the MP2x00 work better than expected. I am super thrilled that I will be able to offer backup boards, ROM fixes, and Extensions on boards that can be reprogrammed over and over.

The original MP has 8MB of ROM on a removable card. I replaced old-school ROM chips with modern Flash memory. The Newton Operating System can officially manage an additional 8MB block and another 16MB block.

By now, I fully tested adding 8MB of additional packages in that first block. With a dedicated programmer, that can be done now. I am writing software that will enable this feature for everyone.

8MB on a Newton are a lot of apps. But we have an additional 16MB that can hold even more packages. This is mostly tested, works with the programmer, and will eventually also be programmable by the user.

Both blocks extend your machine's ROM. They can be written with an app, but they do not extend the Flash RAM of your machine.

So we know how to address 8+8+16MB=32MB of the card. The hardware interface of the card has an additional address pin, which appears very much like an afterthought. It's not used by the OS, but it is very much addressable by the CPU, so we actually have an additional 32MB of memory available. I am not sure if that can be used easily for anything, but it's there nevertheless.

 - Matthias

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