pokey wrote:
I'm pondering on a design of something like the essentials of 6502-based home computer that could have been made in a400/a800 era.
Cool. So a retro vision, but implemented in FPGA?
pokey wrote:
Given that I'm totally clueless when it comes to electronics I'm almost certain that I'll never get it done but still can't stop - it's too much fun.
Hmm. Reading that, I'm reminded of an entertaining remark from one of the other forum members:
Arlet wrote:
Most progress is made by people underestimating the problem
pokey wrote:
If I remember correctly Atari (before Sally) had to go for clock stretching and I don't remember why (my guess is that RDY is leaving the bus in a state they where not happy with, but I really need to look it up)
I'm also unsure, but it could well be because of the "slight exception" I mentioned -- ie, that, with NMOS CPU's, the RDY input won't halt a write cycle. That could be a show-stopper if -- as with video -- timing irregularities can't be tolerated. So, not exactly slight, in those circumstances.
-- Jeff
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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html