So it turns out my 1 bit ALU--which has both circuitry for our accumulator and a tristate circuit to write to our bus, works correctly! Over the next week my plan is to assemble 8 of them and hook them up to my ALU.
My accumulator boards just showed up!
They're nowhere near as complicated as the 1 bit ALU boards, but they do contain the accumulator circuit as discussed in our "Introduction to Digital Computers Part 4 video, along with a single tristate circuit for allowing the contents to be written to our bus, as discussed elsewhere in the same video. These accumulator circuits... Continue Reading →
Announcing a new Quick Video: Building an ALU.
So this one is a little different; in this video I show the steps to go from the design of an arithmetic logic unit to actually demonstrating a working 8-bit ALU, made entirely out of 2N3904 transistors. The show notes include links to circuit diagrams and files in case you may want to build your... Continue Reading →
I am unreasonably happy that my 1 bit ALU board works.
One thing about my "Introduction to Digital Computers" series I wanted to verify was that all the circuits designed in the series in fact works correctly. And one aspect of that--which we introduced in the first part of the fourth video--was the complete ALU. While I've taken the liberty to do some minor redesigns (so... Continue Reading →