FPGA VAX update, now DIY TTL computers
ajp166 at bellatlantic.net
Fri Nov 11 18:33:12 CST 2005
>Subject: Re: FPGA VAX update, now DIY TTL computers
> From: woodelf <bfranchuk at jetnet.ab.ca>
> Date: Fri, 11 Nov 2005 16:14:58 -0700
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>Chuck Guzis wrote:
>>Consider the very old Packard Bell PB250--22 bit words, fewer than 400
>>transistors and 2500 diodes, 63 instructions. Power consumption about 40
>>watts, exclusive of I/O:
>>The trick, of course, is to use bit-serial methods. It seems to me that
>>one could greatly simplify construction of a homebrew machine that way.
>>We're not doing this for speed, right?
>Not really that much, it is registers that hog all the logic gates.
>I guess you would save only about 1/3 of your logic gates.
>I got playing around with 74xx logic and the best I can do for my CPU design
>is about 36 chips for a two bit slice. Now who sells 3-input NAND's
>J/K F/F's cheap like they did in the 70's? And lots and lots of 14
74LS10 dip .25 at ea .17 at Q25 |74F10 dip .19 at ea .14 at Q25 |74HCT10 dip .25 at ea .18 at Q25
Even at a buck a chip if your only using 36 of them thats not painful.
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