ALU Construction: Completed Logic Card Full Test

The ALU logic card is now finally complete! … well, it is now I’ve popped the last few relays into their sockets. The final card looks like this:

ALU Logic Card ALU Logic Card (close up)

As the old saying goes: a picture paints a thousand words … I’m not sure therefore how many words a video paints but it definitely seems the best way to demonstrate the card in operation. So, with that in mind, I’ve (painstakingly) put the following YouTube video together which gives a walkthrough of the ALU logic card in operation. This one also breaks tradition with my previous videos, where the only sound is the relays clicking, and has a narrative track added courtesy of my very own ‘dulcet’ tones.

As you can well imagine I’m pretty pleased that everything is working as intended but this is just the beginning … there’s still two other cards needed (the Arithmetic and Control cards) to form the full ALU and then there’s all those registers let alone all the control and timing circuitry coming up … but, for now, I can sit back for a short while and bask in the contented feeling of making something that works.

Regular readers of my blog may know that I’ve been playing catch up and construction has been quite a way ahead of my posts. Well, I’ve now caught up so from now on the posts will be pretty much following the pace of construction. In real terms this means I’ll be posting less often (the construction of this computer is very much a part time hobby) but on the plus side it’ll probably means I’ll be more consistent in my writing in terms of past, current and post tense.

This’ll be my last post now for 2013 … I really, really should get around to wrapping some Christmas presents rather than spending all my time soldering things followed by writing about soldering things. Happy holidays / new year / etc ;)

Published Dec 18, 2013