Welcome to Mr. Latch-up's C64 DTV Advice Column

Featured Dilemma:

Can I Overclock the DTV R1, 2 & 3?

Dear Mr Latch, I see that the crystal used on the DTV is about 32mhz.  What would happen if I installed a 64mhz crystal?  Would I need a heat sink? Sincerly, Mama Caliente Tijuana, Mexico

Dear Mrs Caliente,     Rev2 & 3 ASIC's uses a thick oxide process and probably won't reliably oscillate at 64mhz, but you could drive the xtal in pin with a 3.3v external canned oscillator.   The internal logic should also function at 64mhz or higher.  You'll probably start running into problems with the poor layout on the memory bus before the internal logic fails.   The speeds of the flash memory and SDRAM should be faster(excluding poor layout) than the maximum speed of the ASIC.   At higher speeds the video timing will not work with composite monitors and you'll need to convert to digital out and VGA monitors.   Rev1 is also a thick oxide, but does not have digital pixel outputs bonded, so the best you'll get is 5 bits (4 luma, 1 chroma) for digital video.