[Coco] Superboard discussion: Serial EEPROM

[Boisy G. Pitre]

On May 3, 2004, at 9:40 AM, Bob wrote:
> Agreed.
>
> So, next question, and possibly one for a new sub-topic... how does a 
> 3rd party
> program detect the Superboard? and the installed options? Perhaps 
> another byte
> in the EEPROM with a bit for each option (would the unused 2 bits be
> enough?)... just thinking out loud.
>

Probably the easiest and most sure-fired way to detect the presence of 
the SuperBoard would be to reserve an address in the $FF1X or $FF3X 
region which when POKEd, would return data about the board.  For 
instance:

POKE &HFF3F,0
?PEEK(&HFF3F)

Would return 'S'.  Then...

POKE &HFF3F,1
?PEEK(&HFF3F)

Would return 'u'....

And so on and so forth.  The value POKEd into $FF3F would correspond to 
the position in the string where the character would be returned on the 
next read.  We could also embed serial number information this way.  So 
a maximum of 256 characters could be stored this way.  Such a string 
could be:

SuperBoard Rev 1.0 (Serial #0001)

Of course, when POKING and PEEKING on a non SuperBoard CoCo 3, you 
would likely NOT get an S, u, etc...  so you could immediately detect 
the presence of a SuperBoard.