Soldering of the Octal D-Latch

A project log for AYTABTU - Discrete Computer

After the apocalypse we have to build computers from stuff we can make at home, I.E Transistors, diodes and resistors.

matsengmatseng 07/13/2015 at 02:440 Comments

This is the result of 2.5 hours of bending, cutting and soldering. Not too shabby I must say...

Since I'm not sure of what voltage I'll run this on I used 1K as collector resistors and 10K as pullups. When the entire board is powered up and outputting low on all NAND gates I measured 420mA power consumption at 12V. That's enough to get the board slightly lukewarm. On 12 volts maybe 3K3 would be a better choice, but currently I really don't care about power consumption

The parts that went onto the board

96 pcs of 1N4148 diodes, 32 pcs each of 1K and 10K resistors and 32 pcs of 2N3909 NPN transistors.

Top and bottom side of PCB

This is the PCB when wired up as 32 individual 2-input NAND gates. Each "column" in the board will have its inputs and outputs interconnected to make them into D-latches, so there will be some flywires.

I also need to hook up the common D- (data) line as well as the 8 clocks and the 8 outputs to pin header connectors.