Bill of Materials

Here is what I think is my bill of materials for the CPU. I actually bought a whole heap of other components and things to build the thing, but this is what I can work out you actually need. It would be good to have a few other things, e.g. a multimeter, a soldering iron, a logic probe, a digital oscilloscope.

Part

Purpose

Quantity

Comments

A623308A-70SF

RAM

1

Overkill, only need 256 x 4 bit SRAM

AT28C64B-15PU

ALU ROM

1


AT28C64B-15PU

Control ROM

2


74LS157

4-bit 2-to-1 Multiplexer

1


74LS161

4-bit register

2

A and B registers

74LS161

4-bit register

1

Flags register

74LS161

4-bit register

2

Program Counter

NE556

Timer chip

1

One-shot and astable clock signal

5mm LEDs

Debug output

Many

Buy many, you will break some!

Pin headers

To mount the LEDs

100 pins

Buys lots, they are cheap

1M resistor

Clock circuit

1


1M variable resistor

Clock circuit

1

Get one that fits on a breadboard

1K resistor

Clock circuit

3


1uF ceramic capacitor

Clock circuit

1


0.1uF ceramic capacitor

Clock circuit

3


Pushbutton

Clock circuit

1

Get one that that fits on a breadboard

22 AWG Solid Tinned-Copper Hook-Up Wire


Six colours

I bought several 25ft rolls

UM245R

UART interface

1

Allows serial output from CPU

74LS32 OR gate

UART interface

1

Decodes Aload and Bload

0.1uF ceramic capacitor

Noise suppression

Many

Sprinkle them between Vcc and ground next to all chip’s ground lines

47uF electrolytic capacitor

Noise suppression

1

Put it between Vcc and ground where you supply 5V power to the system

Breadboard


3

I bought BusBoard BB830 boards

Heatshrink tubing



Enough to protect bare wiring, e.g the LED arrays

Jumper cables


40 pcs

Male to male, so I could quickly make connections when testing things

Wire stripper


1


TL866CS Pro ROM Programmer


1

Expensive yes, but runs on Linux and makes writing to and reading from ROMs easy