Programming 2708's

[Tony Duell]

> 
> I have a DataI/O model 19 and I think I have a 2708 plug-in for it.  The
> reason that most programmers don't support the 2708 is because it requires
> three voltages to operate. Come to think of it, I have a couple of old

Not just that, the programming algorithm is different to most other 
EPROMs. IIRC you have to program all locations in sequence, giving each 
one a 1ms (IIRC) programming pulse, and repeat that 50 times. You can't 
program odd locations like you can in later EPROMs.

FWIW, I thiok the 3rd party progammer I have for the Nascom does 2708s. 
And I haev at least one plug-in card for the Apple ][ that claims to 
program them. And a stnad-alone programmer controlled by an SC/MP that 
does just about everything from 2704s to 2732s.

-tony