My6502 Progress

At 01:39 PM 2/10/00 -0500, John Wilson wrote: ... [nice description of the Super Elf deleted] ... The original "Elf" was a design that was done in a two part article in Popular Electronics (IIRC) that was titled "Build this Elf Microcomputer for $99". Needless to say the idea that I could build one of these new fangled Microcomputers for $99 was a real thrill. So I bought the pre-etched circuit board that they offered in the back with the "basic chip set" and built it. With only 256 bytes of RAM it was sorely limited in what it could do, but not long after that article Quest started advertising "The Super Elf" which I scrounged up the cash for and bought as well. (since sold to another list member :-)) I even got the Super Elf enclosure and didn't extend it past the original expansion board. Then Neutronics(sp?) came out with their Elf kit and it had three or four S-100 type slots on the main board. My room mate got one of those (always had to have a computer _slightly_ nicer than mine :-) The really innovative thing about the Elf was that it was a CMOS part (in a land dominated by NMOS and PMOS chips) and the timing on the externally driven DMA cycle was such that you could build a front panel for it that would use the chip's DMA capability to DMA data into memory. This made the front panel trivial to build (and hence the $99 price tag). The worst thing about the Super Elf was that it used three of four diodes in series with the transformer in an attempt to drop the voltage enough that the 7805 wouldn't overheat trying to drop 12V and drive 500mA. --Chuck