Intel Releases 4004 Schematics – Great for Students
11/15/2006Intel today released the schematics of the 4004, the world’s first microprocessor on a chip. The 4004 was released 35 years ago today, on November 15, 1971. This revolutionary chip had only 2,300 transistors (compare that with the millions of transistors found on microprocessors today). It supported a maximum clock speed of 740kHz and used 4-bit data words. Today’s chips are 5-6 orders of magnitude faster and use 32- or 64-bit words.
No human alive is capable of analyzing today’s processors at the transistor level. Digital design these days happens largely at the block level. Simply put, a group of engineers design the individual blocks (arithmetic unit, floating-point unit, registers, data control, bus, etc.) and then another group combines the blocks to create the processor. Specialized software programs, called CAD or Computer Aided Design tools, exist to make this process simpler. They determine how the millions of transistors will be laid out and how they will be wired together.
The 4004, on the other hand, was designed during an era where computers were mostly glorified calculators. Every one of the 2,300 transistors used in the chip was lovingly drawn into the schematic by an engineer. This makes it possible for anyone who has taken at least a semester of logic design to grasp the majority of what’s going on in this chip. These schematics are invaluable for undergraduates who are seeking comprehensive examples beyond those provided by the textbook of complete but simple digital systems. I would have loved to be able to look at these last year and see how my classroom knowledge lined up with a real, commercial product.
