Hi

I am trying to implement some changes in an Arduino based IC tester to test SRAM (2114) and 6522. Eventually extending it to 6502 and alikes.

But its not working very well. The only thing with the Arduino implementation is that it is very slow. So I was thinking of speeding it up, but that gives me the question: how slow can it be to test some of the 6522, 6502 and alike?

The modern 65C02 are static and can use a push button for a clock, letting it run as fast (or slow, or not at all) as you can push the button.

I can't speak to the NMOS versions.

Minimum speed for the NMOS processors is around 100KHz, if memory serves me. Below that the registers will start "fading out." As whartung noted, the static core 65C02 can be clocked down to zero Hz, which is also the case for the 65C816.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

I see BDD posted while I was typing. I'll post anyway. [Edit: Now I'm having trouble with the hotel's internet connection.]

Like whartung said, the CMOS version can have the clock stopped. However, Western Design Center's (WDC's) W65C02S is the only one that can have the clock stopped in either phase. Others like Rockwell's or Synertek's only allowed the clock to be stopped with phase 2 high. It couldn't be left low for more than about 5µs IIRC. The NMOS version (6502, with no C in it) has a minimum clock speed of about 100kHz. If you go much below that, it will begin to forget where it was and what it was supposed to hold in various registers.

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Ok. Thank you for the responses. The current Arduino code is way too slow then, which kind of explains why it wasn't working.

I will try to implement a faster test-logic for specific chips. If I remember correctly I can get it to above 100kHz with some assembly.