Re: Apple 1 replica is almost finished

[Michael J. Schülke <news0308@mjschuelke.de>]

Vince Briel wrote:
> 
> Let me know what you think.
> 

Congratulations -- that's a very nice project! If you are thinking of 
having a batch of boards made, I'd be very interested in buying one. 

I've got a few questions, though:

- Why are you using a an AT90S8515 rather than a ATmega8515? The latter 
are pin compatible replacements, but can run at twice the speed while 
costing 25% less [1]. Besides, Atmel is phasing out the AT90 line in 
favour of the ATmega and ATtiny lines -- already, the 90S8515 is no 
longer recommended for new designs. 

- Why are you using NTSC composite (or PAL? you don't say) rather than 
VGA video? The ATmega should be fast enough for the latter, the image 
quality of a VGA monitor is much better than that of a television or 
composite monitor, and you'd be avoiding problems with different 
television standards. 

(BTW -- this could probably be solved simply by reprogramming the 
controller, with little changes to the hardware other than a different 
connector.) 

- Can the µCs be reprogrammed on the board, or do you have to remove 
them? 

Finally, note that the link "The Circuit" on the web page is broken. 

Regards,
Michael 


[1] at least where I'm buying my components -- www.reichelt.de