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Amiga Hardware Issues and discussion / Re: I made a modified accelerator, it works, but has a problem
« Last post by r00tb33r on April 19, 2024, 05:06:23 AM »I re-read Dennis's project notes and found that this statement may have been a clue.
I put a variable 0-60ns delay line on /AS output of the U5 JK flip flop and found no value that made a difference with respect to the interrupt counts. No success here, at least the way I did it.
Earlier I also came across the following resource:
https://sites.google.com/one-n.co.uk/amiga-guides/amiga-interrupt-signals
And noted that the pullups on the interrupt lines became stronger on newer revision Amigas, from 10Kohm on earlier models to 1Kohm on newer. I did try adding 1Kohm resistors from 5V VCC to /INT2, /INT3, and /INT6 lines, but that made no difference in my case.
Ideas?
Quote
AS is now delayed before being fed to the motherboard fixing issues when the CPU does a chipset cycle after a CIA cycle.
I put a variable 0-60ns delay line on /AS output of the U5 JK flip flop and found no value that made a difference with respect to the interrupt counts. No success here, at least the way I did it.
Earlier I also came across the following resource:
https://sites.google.com/one-n.co.uk/amiga-guides/amiga-interrupt-signals
And noted that the pullups on the interrupt lines became stronger on newer revision Amigas, from 10Kohm on earlier models to 1Kohm on newer. I did try adding 1Kohm resistors from 5V VCC to /INT2, /INT3, and /INT6 lines, but that made no difference in my case.
Ideas?