Date   : Thu, 23 Oct 2008 19:42:25 -0500
From   : jules.richardson99@... (Jules Richardson)
Subject: A500 development ROMs

Pete Turnbull wrote:
> On 23/10/2008 19:56, Jules Richardson wrote:
>> Pete Turnbull wrote:
>>  (I think ARX and Panos are both heavily m2-based, too)
> 
> Panos possibly,

It's definitely Modula-something, I just don't recall if it was -2 or -3.

> ARX I'd be less sure about but I never saw it. 

I do have some ARX stuff somewhere - although it's been a while, so I really 
don't remember if there were binaries or sources or what. I'll have to do some 
poking around, although I won't get a chance tonight.

Actually, amazingly, there is a wikipedia entry for ARX - it says it was m2, 
but I'm never 100% trusting of wikipedia :-)

>>>  Arthur was not the OS on the A500 development systesm, either.
>> I still suspect it was just Brazil in ROM, and from there you could load 
>> whatever you wanted from disk - be it Arthur or something else entirely.
> 
> That would make complete sense.

My brain just stuck a 'non' in front of 'sense'...

>  The A500 was purely a development 
> system for the Archimedes range, and as such was used to test and 
> develop the modules that made up Arthur, one by one.  In the early 
> stages of development it was hooked up to a BBC as a second processor, 
> so the Beeb would provide all or part of the I/O -- and I still have one 
> of the Tube podules that was used for that purpose.  Later, when they 
> could be used as machines in their own right, many of the A500s were 
> loaned to software developers.

Remember that there was also an 'A500 second processor' (as opposed to 'A500 
machine with a TUBE podule') - very little seems to be known about that 
particular beast.

I'm wondering now, though. According to data that I have, the A500 had 512KB 
of ROM - that's way more than any Brazil I've seen (16KB on the ARM eval kit, 
64KB on the Springboard and M4). Perhaps that was just theoretical maximum 
though, I suppose (and was based on observing the majority of A500s in the 
wild that have had RISC OS upgrades). I've got the darned A500 TRM, which 
might say, but it's in storage back in England...

All this talk's making me regret not picking up an A500 that I was offered a 
couple of years ago - I'm not really into the ARM systems, but firing up 
something like Arthur would be interesting. I wonder how feasible an A500 
emulator is... (hooking up something against the TRM schematics would be 
possible, I suppose, but given the lack of software, validating that it worked 
as it should might be tricky - and I'm not sure that the TRM covered the 
A500's keyboard wiring)

cheers

Jules