Intel 4004 simulator and tools

Doug <doug(a)blinkenlights.com> wrote: Hi Doug The SIM4-01 was made to take 4 1702's for program ROMs and had 4 4002 RAM chips. The board had simulated I/O to act like the I/O that came on the 4001 mask ROM chips. There was also a SIM4-02 board that could take up to sixteen PROMs and had sixteen 4002 RAM chips. The MCS-4 chip set originally included 4004 ( uP ), 4001 ( Mask ROM and 4 I/O pins ) and the 4002 ( RAM and 4 Outputs ). Later additions were the 4003 ( Serial/Parallel I/O ) and 4008/4009 ( TTL level converters ). The Intellec-4 was made later. The Intellec-4 was soon replaced with the Intellec-4/40 that used the newer 4040 version of the 4004. They were bus compatible. When I was at Intel, I think we were the last to use the 4040's in our UPP ( Universal Prom Programmer ). The 4004 used a Harvard architecture and had some what of a restricted instruction set. It didn't even include such things as bitwise AND and OR. These had to be generated by using the add instruction and built a bit at a time. The adder at a bit location is the XOR of the bits and the carry generated is the AND of the bits. The SIM4-01 usually came with a back plane board called the MCB-4 and a PROM programmer card called MP7-0x. Depending on revision, it was designed to program 1702, 1602, 1701, 1601 and later versions did 1702A's. It should also be noted that, as I recall, Intel also made the first EPROMs. The SIM4-01 board came with 3 PROM's with code to program the PROMs. The board, using the I/O space of the ROM's and RAM's, had a 20ma current loop serial. Luckily they were using ASCII instead of Baudit in those days. I made a simple RS232 interface to convert to my PC at 110 Baud. I'll try to get a picture up on my web page for show and tell. Intel originally made the 4004 for a company call Busicom. It was to be used in one of their calculators. It was dropped in favor of a dedicated calculator chip but as we know, many applications were just waiting for the uP to happen. I'm not sure of all the dates but the 4004 was introduced in 1971. My SIM4-01 board has all the date codes in 1972. Many think that the 8008 was the first 8 bit uP but Fairchild was first with a two chip F8 by a small margin. Wow, I feel old. I remember reading about the 8008 when it first came out. Dwight