Intel 4040 - was Intel 4004 simulator and tools

Sam Ismail <dastar(a)ncal.verio.com> wrote: Hi Sam From the outside, the 4040 was quite similar to the 4004. The 4040 was in a different 24 pin package but used the same multiplexed 4 bit bus and could use the 4001/4002 parts. There may have been many differences internally. Code wise, the 4040 will run all of the 4004's machine instructions and there were about 10 or so instructions added. There was a slight difference about what was on the bus during the execution cycles. As I recall the 4040 had the ALU available on the bus during the last cycle. I have a data manual describing all of the 4004 and 4040 instructions. As was mentioned, the 8008 was quite a bit different. When I worked at Intel in the late 70's, I worked on the UPP ( Universal Prom Programmer ). I was involved in system test. There were few tools made to deal with debugging these early uP's. I built what I called a "Slow Time Ice". One could remove the 4040 and plug this unit in. I ran a continous clock on the 4040's buss and would take input from a MDS800 or Series II. It allowed one to read/write any of the ROM, RAM or I/O on the UPP. Only one of these was ever built. As for the questions of where I got the 4004, I found it at a local electronic surplus store. I bought the entire setup for $25, as I recall, about 10 years ago. I knew it was a valuable item to save. For those that don't have a 4004 to play with yet, they can use my Assembler/Simulator to play with the instruction set. It isn't quite real hardware but almost runs as fast. Dwight