[sebhc] New CPU card

Carroll Waddell CarrollWaddell at sc.rr.com
Sun Jun 13 14:38:44 CDT 2004

That's an interesting idea, but finding some of the parts would be 
difficult. The front keypad switches might could be replaced with 
something a little more modern. I've never found those key switches 
anywhere else. By the way, if you have an old H9 terminal to salvage, 
I'm pretty sure the H9 keyboard used the same switches as the H8 front 
panel. I'm sure your idea could be built, but I feel like the board 
would be too crowded to put together as a kit. Of course, it might still 
be possible. I've always believed that almost anything is possible.

Lee Hart wrote:

>Carroll Waddell wrote:
>>As soon as I get my H8 up and everything working correctly, I thought
>>about building a new CPU card. Based on Pat Swayne's Z80 upgrade
>>article, how about a new board with a Z80 processor, 64K RAM, and the
>>extended configuration (the little board in P10) all on one card?
>>Anyone interested?
>Yes! In fact, I was thinking of something similar. My thought was to put
>the Z80 and 64k of memory on the front panel board! Thus, *no* bus slots
>would be taken up for CPU or memory.
>We could also eliminate the discrete wiring between front panel and
>motherboard. The thought is that such a board could be the basis of a
>kit to get *new* people interested in the H8. They could build just the
>front panel+Z80+memory and have a working single-board computer. Add the
>motherboard and accessory boards to expand it into a "real" system.
>The other advantage to this (for present H8 owners) is that the bus can
>stay at 2 MHz, while all Z80-memory accesses can run at a much higher
>speed (8 MHz Z80s are essentially the same price as 2.5 MHz parts). For
>legacy support, we could even have a way to select CPUs, so you could
>even leave the old 8080 and memory cards in the system and run them.

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