[NTLK] Reading ROMs the other way

[Matthias Melcher]

On 08.09.2013, at 18:53, Andrei Chichak <newton at chichak.ca> wrote:

> 
> On 2013-September-08, at 7:32 AM, Matthias Melcher <mm at matthiasm.com> wrote:
> 
>> 
>> Hi Newton fans,
>> 
>> In my everlasting quest to solve the 2-million-squares Sudoku that is the Newton ROM, I played a bit with hardware as well. I removed the ROM board from a dead MP2000 and the ROM slot from an eMate - also dead - and made a board that fits onto an Arduino. I can now read any ROM or Flash board out there without the need of a working MessagePad.
> 
> 
> It's time like this that I wish that the Arduino had an ARM processor or the Raspberry Pi had a bit more of a bus. 
> 
> I wonder about the Arduino Due, are the address and data busses adequately exposed to allow code execution?

Yeah, the Pi is quite low on pins. Also, thanks to the complex OS, timing is not that easy. Controlling stepper motors from the Pi is a pain thanks to unpredictable timing.

I don't think that the address and data bus are available at the CPU at all. It's more a system-on-a-chip with 96k of RAM and 512k of flash.

http://arduino.cc/de/uploads/Main/arduino-Due-schematic.pdf

Depending on the job, it might make sense to have an Arduino do the grunt work (control the steppers and ink cartridge in a printer, for example) and have a Pi manage the ethernet acces and higher level stuff. Then connect them via SPI.

 - Matthias