Ok, my AGA overclocking was done with a programmable PLL clock.
(Never had a stability issue related to the acceleration itself.)
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-Bad Effects-
Bad system clock
Floppy drive access useless.
Genlocks disabled it.
Need a multisync monitor, &, 'MonED' to make all the new possible monitor modes.
Audio was also off.
Serial port was also off, however, I made a little utility to fix the baud rate.
requires the change of the chipram module.
MUST HAVE fanned heatsinks on all of the Amiga's chipset chips.
-Great Effects-
60Hz 640x400 was possible in the non-DLB scan aga mode not only freeing up double time CPU to chipram access for those 35ns/pixel modes, now you use the 70ns/pixel, the chipram controler was also almost double speed. This made the software only version of lightwave layout editor in a 60hz progressive mode run at 4x speed, it scroll smooth like silk with complex scenes.
48Khz audio.
After the serial port patch software, far better 38400 performance.
Parallel port operated at extreme speeds.
PLL design allowed real-time system clock speed changes.
Additional hardware clock line tied to the floppy drive also made it read at almost 2x speed, however, writes were not guaranteed to be good.
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Though I can easily make a replacement 'Turbo-AGA' pcb today, there is absolutely no financial incentive to do so, +, if I sell my A4000, I will no longer have a test fixture.