Computer First Microcomputer in USA - 4 bit MCS-4 Intellec 4 Microcomputer - Vintage Intel

We are fortunate to have  an MCS-4 Intellec 4 Intel Microcomputer  

MCS-4 Intellec 4

development system in our historical collection.  The Intellec 4 computers are possibly the first commercial microcomputers manufactured (1972) in the USA. The 4004  microprocessor (a 4 bit processor) chip used  in the MCS-4 was introduced in November of 1971 and was the first Intel microprocessor chip.  Only a few of the MCS-4's still exist. The Intel museum does not have one or at least it did not in 1992 when an Intel representative  contacted me to borrow our MCS-4.  They kept the microcomputer for 18 months and used it in some litigation process.  Intel did introduce an additional development computer in 1977 - the MCB8-10 and it looked like a home built system. The MCS -4 was followed by the MCS-8 which used the 8008 8 bit microprocessor. The Bugbook Historical Museum also has one of the MCS-8 computers.

Inside the MCS-4

Serial number 136

The MCS-4 uses a 100 pin bus and has a dozen or so card slots for expansion. It is an operational computer for developing and testing software and hardware.  This was the very beginning of commercial development tools for the microcomputer revolution. Engineers were slow to realize the potential of the microprocessor. The first time user found the MCS-4 a rather complicated   system to use - not much educational information or training was available.  It did not take long before it was clear the microprocessor and the microcomputer were a really big and important new electronic design device.  Now you could write a program to preform any digital or math function and change it with a new program.  For example the early digital calculators used a none programmable Large Scale Integrated Circuit (LSI) and every new calculator required a new design for the LSI chip.

Indeed it was the Japanese company Busicom that sparked the design of the Intel 4004 for their next calculator. Busicom Story here.(from nigel.tout@vintagecalculators.com ) It seems so obvious now but it was about 3 years before the microcomputer was more than a toy for hobby folks to use.

4k RAM memory

4004 microprocessor chip

CPU Card

The CPU card also contains 4 EPROM chips and each chip is 250 bytes or 1kbyte for the 4 white 1702A chips on the board.

     Change in technology 43 years after the 4004 microprocessor
 The MCS -4 memory card is only 4 kilobyte - that is the whole card. This is a good time to try and make a comparison of the 1972 technology with today.   In 1964 Gordon Moore (Moore's Law) predicted integrated circuit technology would double the circuit density on a chip every 2 years. Today a memory card for a laptop computer may contain 4 Gbyte of  RAM memory.  It would take 1,000,000 - yes one million of the 4kilobyte RAM cards like the one in the in the Intellec 4 to have the same amount of memory as the 4 Gbyte card.
Now if you laid the 1,000,000 Intellec cards out end to end it be a string of cards 2300 miles long.
One more calculation - a common 64Gbyte USB memory stick would require a string of these Intellec cards 36,000 miles - that is circling the earth 1.5 times.  The USB Memory stick cost about $35 -- these comparisons are just amazing and just give it 5 more years WOW.

The first Intel Microprocessor was the 4004 chip and a little later they came out with the 4040 microprocessor. The 4040 was still a 4 bit microprocessor but much faster in operation.  The same hardware as the Intellec 4 shown in this blog was upgraded to use the 4040 - it was called the Intellec 40 Mod. Here are some photos of the 40 Mod that give you a good look at the computer hardware. The 40 Mod is basically the same except for the CPU card as the Intellec 4.


 Here is a video of the Intellec 4 in our Bugbook Historical Microcomputer Museum"CLICK"


Here is a video story about the 4004 and Intellec 4 by Intel - interesting about the first commercial microprocessor "CLICK"

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This weekend my wife Gaynell and I are flying out to Missouri to visit my 91 year old brother.
He is doing well but we like to visit at least once per year. The Birthday party we went to in NC last weekend for our 1 year old Great grandson Tucker Helms was fun. The weather was nice most of the time but at the end of the day it did rain on our outdoor party. Weekend before we were in MD for the16th Birthday of our twin Grand daughters Natalie and Emily.  Lots of travel but worth every minute. Looks like we will be home for a few weeks after this trip and looking forward to being home.
"by David Larsen" KK4WW Computer Collector/Historian