On Fri, 9 Mar 2001 ncoplin@orbeng.com wrote: > Any other suggestions for chips which could be off-lined or swapped to save > a few mA? The $dd00 CIA can be removed from the board altogether if you don't need the user port or the serial bus. Many programs don't switch the 16k video bank from its default location (0-$3fff), so you don't need the chip for that either. For mass storage (or even for replacing the KERNAL/BASIC ROM), you could use a Flash ROM. AMD Am29LV160D looks quite promising. Its only disadvantage for this project is that its operating voltage power supply must be between 2.7 and 3.6 volts. You'd require some address and data bus buffers, e.g. the Texas Instruments SN74LVC244A. The VIC-20 all-in-one cartridge I and a couple friends of mine are developing will probably use this chip. It doesn't require a special voltage for programming or erasing; you just have to write a "magic cookie" to certain addresses to enable the programming mode. An even wilder thought would be to use 3.3-volt programmable logic, such as the Lattice 2032 (or bigger), for replacing the 6510 and the PLA. By using static RAM (like two 62256's), you wouldn't require any memory refresh, or any VIC-II. But these improvements would probably require a completely redesigned circuit board. 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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