[Coco] [Color Computer] Re: Coco flash cartridge

[Phill Harvey-Smith]

Mark McDougall wrote:
> James Diffendaffer wrote:
> 
>> Based on CoCo3 high
>> speed timing you should be able to use a 24 bit register for the
>> counter and handle at least 5 seconds.
> 
> There's only a handful of flip-flops left in the EPM3032... perfectly 
> do-able in the 3064 of course for an extra USD or 2...
> 
> Was wondering about the SCS# decoding for the flash cart register space. 
> I'd imagine a lot (most?) of the commercial carts would actually have 
> ROM data mapped to that space, so running that code on this cart would 
> be a problem!?!

The way I handled the bank select was to have the menu running from the 
rom in bank 0, and available on reset. When the user had selected the 
prog to run from the menu I copied a little bootstrap routine into RAM, 
which would then select roms and do copies to ram as apropreate.

Cheers.

Phill.

-- 
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !

"You can twist perceptions, but reality won't budge" -- Rush.