On Fri, 23 Feb 2001, Professor Dredd wrote: > My brother just sent my documents detailing a hack to > run the C64 at 2 Mhz. It looks really simple, but my > electronics skills are far to rusty to implement it. Then I guess it can't be the same hack that was published in the 64'er Magazin 2/94 or 3/94. That hack used lots of logic glue to implement the I/O port at locations 0 and 1, and to construct a clock signal that generated two clock pulses for the CPU during the CPU bus cycle halves. In other words, it ran the 6502 at 4 MHz for 2 cycles and at 0 MHz while the video chip was doing its transparent DMA. In this way, the computer ran at 2 MHz with the screen turned on. Another possibility is to use a C128 video chip to produce the exact equivalent of the C128 "2 MHz mode" on a C64. Marko - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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