Philippe I’m surprised you are getting away with only one wait state, I seem to remember I have 2 or3 for 10 MHz. If people have problems at these speeds may want to play around with wait states, particular for I/O. John From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Philippe Elie Hi folks, a quick update in case this can be of interest to others : even after the above modifications, I ran a infinite test loop (a turbo pascal program incrementing an integer and displaying the result) and discovered the display was hanging after around one hour. I ran a RAM test with no IOs that worked perfectly well. I started to suspect the console IO timing, and indeed that was the issue : i swapped the 244, 32, 04 and 00's for F versions, and the turbo pascal loop is not running since more than 3 hours. note than i use one one wait state for IO, RAM and ROM with a 10 MHz oscillator. -- |