[NTLK] A new ROM board

[DXH]

Congratulations Matthias!

This opens up many possibilities- not least of which is being able to fix all the nagging bugs from the original OS and, perhaps, stripping out the proprietary code to make a truly open source OS.

Removing the chip ID check would enable a wider range of Flash chips to be used now that the Intel chips are obsolete.

As far as the hardware is concerned, I see that 128Mb chips are still available (at least here in US). Mouser has them for $6.65 each. However, I think the 512Mb parts you used give you the option to bank switch alternate ROMs.

Good choice of NOR Flash. Faster reads and slower writes but ROM will infrequently be changed.

NAND Flash is great for program memory.

I like the idea of a software firmware update but I would also include a program header too. That way you have another option to program the board using a commercial programmer. Sure, the required signals are on the edge connector but, a handy header would be, well - handy.

If you have a spare board that you could send me I would appreciate it. I don’t need a programmer.

Again, great job!

Best,

PCBman


Sent from my iPad

> On Feb 22, 2022, at 7:20 PM, Jeff Sheldon <jeffsheldon at gmail.com> wrote:
> 
> Matthias,
> 
> Congratulations on a huge accomplishment.  As you mentioned, this opens the door for original hardware to have different personalities with board swaps.  (Would be neat if there was some way to use empty memory regions for multiple ROM images and control what’s loaded.)
> 
> I had attempted to reverse the ROM board about 15 years ago and abandoned the idea, partly due to the programmer needs.  Very proud of your achievement.  
> 
> 
> -Jeff
> 
>> On Feb 22, 2022, at 18:08, Matthias Melcher <m.melcher at robowerk.de> wrote:
>> 
>> 
>>>> On 22. Feb 2022, at 13:30, Jake Bordens <jake at allaboutjake.com> wrote:
>>> 
>>> Nicely Done.  Can’t wait to get my hands on a couple of these!
>> 
>> So I did manage to boot my MessagePad after all. I took out the old board and put in the new board that I flashed with the US NewtonOS ROM, pulled the power switch, and waited. 
>> 
>> And waited.
>> 
>> Nothing.
>> 
>> Sigh. I put the Newton to the side in frustration, and as I was about to leave the room, I heard a very familiar chime! And then I remembered: when changing the ROM, NewtonOS clears the entire system before booting which takes 15 or so seconds. I was just not patient enough:
>> 
>> https://youtu.be/Ou_3aya1ujI
>> 
>> At the moment, these cards need an external programmer hardware to write the operating system, but I plan to write some app that can update the ROM board while it is in the Newton without hardware.
>> 
>> If anyone has ideas and can help, maybe even write some code, I'll be happy to send a card and a programmer to you.
>> 
>> - Matthias
>> 
>> 
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>> 
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