Building an 8-bit breadboard computer (SAP-1)

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Earlier this year (2020) I got the courage to start building Ben Eater's 8-bit breadboard computer which follows the SAP-1 architecture, from the book Digital Computer Electronics by Albert Malvino.

While this is not an easy task when you don't have much experience in electronics, fortunately I took courses in my uni that involved digital logic, electronics and boolean algebra so it came in as a good foundation from which I can start building up.

You can buy the 8-bit breadboard computer kit directly from Ben, but it only has exact number of components from which you can build the computer. Which is logical, since it's a kit.

However, I went the other way around, and since I wanted to build my own electronics lab at home, I realized this was the chance to start gearing it up. So in early February, I made a list and ordered most of the components online (Amazon, Ebay, Mouser, and mostly AliExpress).

This page will be updated depending on my progress.

Requirement list

Item Qty. Ordered Have
BusBoard Prototype Systems BB830 Breadboards 14 YES YES
22 AWG Solid Tinned-Copper Hook-Up Wire 1 YES YES
1kΩ resistor 10 YES YES
10kΩ resistor 9 YES YES
100kΩ resistor 1 YES YES
470Ω resistor 24 YES YES
1MΩ resistor 1 YES YES
1MΩ potentiometer 1 YES YES
0.01µF capacitor 6 YES YES
0.1µF capacitor 16 YES YES
1µF capacitor 1 YES YES
555 timer IC 4 YES YES
74LS00 (Quad NAND gate) 2 YES YES
74LS02 (Quad NOR gate) 1 YES YES
74LS04 (Hex inverter) 5 YES YES
74LS08 (Quad AND gate) 3 YES YES
74LS32 (Quad OR gate) 1 YES YES
74LS107 (Dual JK flip-flop) 1 YES YES
74LS86 (Quad XOR gate) 2 YES YES
74LS138 (3-to-8 line decoder) 1 YES YES
74LS139 (Dual 2-line to 4-line decoder) 1 YES YES
74LS157 (Quad 2-to-1 line data selector) 4 YES YES
74LS161 (4-bit synchronous binary counter) 2 YES YES
74LS173 (4-bit D-type register) 8 YES YES
74189 (64-bit random access memory) 2 YES YES
74LS245 (Octal bus transceiver) 6 YES YES
74LS273 (Octal D flip-flop) 1 YES YES
74LS283 (4-bit binary full adder) 2 YES YES
Double-throw toggle switch 3 YES YES
Momentary 6mm tact switch 3 YES YES
8-position DIP switch 1 YES YES
4-position DIP switch 1 YES YES
Yellow LED 8 YES YES
Green LED 12 YES YES
Common cathode 7-segment display 4 YES YES


Item Qty. Have
Oscilloscope 1 YES
Probe 1 YES
Wire Strippers 1 YES
Digital Caliper 1 YES