Am 28.10.2015 um 08:56 schrieb Stephen:

>> As an aside, Hackaday.io seems to be full of people building computers
>> "from scratch", using only individual logic gates. One guy claimed to be
>> building a computer from nothing but 7400s...
>>
>> ....until you realise that he means the members of the 7400 family that
>> implement entire counters, encoders, decoders, latches, etc.

Fair enough, as far as I'm concerned.

> I hope he has a big power supply and lots of fans.
> In the mid 70's I built a digital clock out of TTL. It needed 25 amps at
> 5 volts to drive the logic. A couple of years later I built one out of
> CMOS and that would run for an hour on a PP3 battery. (It was mains
> powered the battery was for backup.)

I suspect the guy in question wouldn't be using classic TTL (where on
Earth would you get those nowadays, anyway), but rather LS-TTL, cutting
power consumption to 20%.

I for one wouldn't use 7400-family chips anyway, and instead go for a
CPLD (or, more likely, a collection thereof). Makes it much easier to
make minor design changes even after the circuitry has been wired.


> Funnily enough. His project reminded me of you. Did you not once write
> programs in PostScript or Printer Command Language?

PostScript is fun! Especially since it comes with high-resolution
graphics output fully integrated ;)

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