Forgotten PC History

[Göran Axelsson]

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)

<nitpick>

This doesn't look correct. My 8008 8 bit parallel CPU manual gives the 
following order on the data bits. (Also at bitsavers at 
http://bitsavers.org/pdf/intel/MCS8/8008usersManualRev4_Nov73.pdf )
              8008
             __ __
  (-9V) Vss |  U  | INT
         D7 |     | READY
         D6 |     | phi1
         D5 |     | phi2
         D4 |     | SYNC
         D3 |     | S0
         D2 |     | S1
         D1 |     | S2
         D0 |_____| Vcc (+5V)

</nitpick>

And to answer another question about the screen on the Datapoint 2200, 
it was 12 rows of 80 characters.

Btw, anyone have an Intellec 8 computer they don't need? It's one of my 
"wish list" machines. :-)

/Göran