11 Aug
2008
11 Aug
'08
3:09 a.m.
And then the 1974 8080 seems to be even more different.
It doesn't even look like the same design philosophies on
any of the chips.
bs
On Mon, 11 Aug 2008, Pete Turnbull wrote:
On 11/08/2008 07:37, schwepes at moog.netaxs.com
wrote:
The 8008 was only introduced a year after the
4004 which was
introduced in 1971. I can't find a pin out for either of them
but I suspect that they might be pin compatable so that the
upper four bits would be simply not used if the 8008 was put
in a system designed for a 4004.
Not even close, I'm afraid. The 4004 is a 16-pin device with Vdd (-10V)
and Vss (+5V) on the centre pins of the two sides, the 4 data bits on
pins 1-4, and the two clock phases and SYNC on pins 6-8. The 8008 is an
18-pin device with Vcc (+5V) and Vss (-9V) on diagonally opposite
corners (pins 1 and 10), D0-D7 on pins 2-9, and the clock phases and
SYNC on the other side (pins 14-16):
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)
--
Pete Peter Turnbull
Network Manager
University of York