4004/8008 (was Re: Forgotten PC History)
pete at dunnington.plus.com
Mon Aug 11 07:36:45 CDT 2008
On 11/08/2008 09:56, Ethan Dicks wrote:
> On Mon, Aug 11, 2008 at 08:29:28AM +0100, Pete Turnbull wrote:
>> 4004 8008
>> __ __ __ __
>> D0 | U | CMRAM0 (-9V) Vss | U | INT
>> D1 | | CMRAM1 D0 | | READY
>> D2 | | CMRAM2 D1 | | phi1
>> D3 | | CMRAM3 D2 | | phi2
>> (+5V) Vss | | Vdd (-10V) D3 | | SYNC
>> phi1 | | CMROM D4 | | S0
>> phi2 | | TEST D5 | | S1
>> SYNC |_____| RESET D6 | | S2
>> D7 |_____| Vcc (+5V)
> I don't happen to have the 4004 datasheet handy (and can't get to it
> for a number of hours), but the -10V Vdd requirement makes me wonder
> if it's possible/feasible to use a pair of ganged ICL7660s (still made
> by Dallas/Maxim) to generate it.
It takes about 30mA to run a 4004.
> I don't see a GND pin on the 4004, so I'm at a loss to estimate
> what it would require for Vdd. Anyone know or can check easily?
Some data sheets list Vdd = -15V and Vss = 0V, so the -10/+5 is just a
convenience. Logic levels are relative to Vss.
> Also, does anyone know about any sort of 4004 emulator or simulator?
> I wouldn't mind trying my hand at some code *before* trying to build
> out the hardware.
The whole manual is available at
I came across this while looking for something else:
Never tried it, but it might be a place to start.
Pete Peter Turnbull
University of York
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