FPGA VAX update, now DIY TTL computers

Allison 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 
>and Gated
>J/K  F/F's  cheap like they did  in the 70's?  And lots and lots of 14 
>pin Sockets!

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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