Turing Complete - The What, Why, And How of the Intel 8008

In this video I talk about my mockup of the Intel 8008 microprocessor inside Turing Complete. I discuss some history of the 8008 itself, how that history led to some particular design decisions and interesting parts of the chip, and how the features translated (or didn't translate!) into Turing Complete. I also demonstrate the chip running in some of Turing Complete's puzzles.

My guess that the division program did not work because of messing something up while expanding the components on the new patch was correct. I tied the m1 and m3 control lines of the ALU together for bit-slices 0 and 2 (only those two). The division program broke because this turns an XOR operation into an ADD operation on those bits, which gave the wrong answer.

More user-facing information about the 8008 can be found [in the 8008 User Manual](http://8008.classiccmp.org/8008UM.pdf) which was shown in the video. Detailed information about the ISA, and some programming tips and tricks, can be found in the [Programmer's Manual](https://www.8008chron.com/MCS_8_Assem.... Note that Turing Complete's assembler doesn't (currently) make it possible to use the true assembly syntax.

As can be seen on the bottom wire, a huge thanks for this project goes to Ken Shirriff, whose excellent analysis of the 8008's [die](http://www.righto.com/2016/12/die-pho..., [counters](http://www.righto.com/2017/03/analyzi..., and [parallel ALU](http://www.righto.com/2017/02/reverse...) got me started on this project. Without his existing analysis to let me focus on my TC building and layout skills while starting this project, I do not think I would've completed it. Ken also very kindly sent me an extra die photo which was very helpful to understanding the instruction decoder and some of the fringe areas on the chip.