Free (old!) micro-processor

[Karl W4KRL]

My first "computer" was a COSMAC ELF built from the Popular Electronics
Magazine articles. It used the CDP1802.

http://en.wikipedia.org/wiki/COSMAC_ELF

73 Karl W4KRL

-----Original Message-----
From: Gerald Wolczanski [mailto:jerrywlinux at comcast.net] 
Sent: Friday, March 29, 2013 3:17 PM
To: tacos at amrad.org
Subject: Free (old!) micro-processor

Sorting out some of my parts and I find a "CDP1802", a 40-pin device.
Researching I find:

The RCA 1802 has a static CMOS design with no minimum clock frequency, so
that it can be run at very low speeds and low power. It has an 8-bit
parallel bus with a bidirectional data bus and a multiplexed address bus
(i.e., the high order byte of the 16-bit address and the low order byte of
the address take turns in using the 8-bit physical address bus lines, by
accessing the bus lines in different clock cycles).

The RCA 1802 has a single bit, programmable output port, and four input pins
which are directly tested by branch instructions.

Its I/O mode is flexible and programmable, and it has a single-phase clock
with an on-chip oscillator. Its register set consists of sixteen 16-bit
registers. The program counter (PC) can reside in any of these, providing a
simple way to implement multiple PCs, pointers, or registers.

MORE IMPORTANTLY:
The Galileo spacecraft used multiple 1802 microprocessors

ANYBODY WANT THIS?  

Jerry
KI4IO
Warrenton

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