Parts List
Listed below are the complete parts list used in building the 8-bit computer project. It cost us roughly ₹5000 including 12 breadboards, excluding the tools and power supply. There is no hard and fast rule that the mentioned ICs or commponents must be used. Alternatives and subtitute ICs can be used as long as the parameters are adjusted.
Links to Datasheets for each ICs is also listed below in the table. Motorola Datasheets are prefered as they are much more detailed, with correct circuit diagrams and pin-outs.
The below listed ICs may be subjected to availability. Alternatives/Substitutes may be used.
ICs
| IC Name | Part Number | Quantity | Datasheet |
|---|---|---|---|
| Timer IC | LM555 | 4 | Texas Instruments |
| Quad NAND gate | 74LS00 | 2 | Motorola |
| Quad NOR gate | 74LS02 | 4 | Motorola |
| Quad NOT gate | 74LS04 | 4 | Motorola |
| Quad AND gate | 74LS08 | 4 | Motorola |
| Quad OR gate | 74LS32 | 4 | Motorola |
| BCD to 7-segment | 74LS47 | 2 | Motorola |
| Dual JK flip-flop | 74LS76 | 1 | Motorola |
| Quad XOR Gate | 74LS86 | 2 | Motorola |
| 3 to 8 decoder | 74LS138 | 1 | Motorola |
| Dual 2 to 4 decoder | 74LS139 | 4 | Motorola |
| Quad 2 to 1 multiplexer | 74LS157 | 4 | Motorola |
| 4-bit BCD counter | 74LS161 | 4 | Motorola |
| 64 bit RAM | 74LS189 | 4 | Generic |
| Octal transceiver | 74LS245 | 4 | Motorola |
| Octal D flip-flop | 74LS273 | 4 | Motorola |
| 4 bit binary adder | 74LS283 | 4 | Motorola |
| EEPROM | AT28C16 | 4 | ATMEL |
Components
Certain breadboards have the power rails broken on the middle on both the sides. Connecting those rails with jumpers is another hassle. Good quality standard sized breadboards with common power rails are preferred.
| Component | Specifications | Quantity |
|---|---|---|
| Breadboard | MB120 | 12 |
| Connecting Wire | Single Core | - |
| Resistor | 220Ω | 2 |
| 330Ω | 2 | |
| 470 Ω | 2 | |
| 1K Ω | 2 | |
| 10KΩ | 2 | |
| 100KΩ | 2 | |
| 1MΩ | 2 | |
| Potentiometer | 1MΩ | 2 |
| Capacitor | 0.01uF | 4 |
| 0.1uF | 2 | |
| 1uF | 2 | |
| Switch | SPDT | 4 |
| Button | Push | 4 |
| DIP Switch | 4 bit | 4 |
| 8 bit | 4 | |
| LED | Red | 4 |
| Green | 4 | |
| Yellow | 4 | |
| Blue | 4 |
Power Supply
The power connections are a sensitive part, an unstable power connection may cause inconvinience. A Dual Power Suppy is suggested although normal adapters will also work, provided it satisfies the current requirement. Alternatively, 5 volts from SMPS can also be used.
| Item | Specification | Quantity |
|---|---|---|
| Battery/Adapter | - | - |
| Buck/Boost Converter | 5V 3A | 1 |
| SMPS | - | - |
**A constant voltage power source is required, else the program counter will malfunction.
On this setup, 5V from a 350W SMPS is used to provied power to different modules of the system.
Tools
Not mandatory to have, although it will make the work much easier. Multimeter is necessary for testing the connections/resistance/voltage.
| Tool | Specifications | Quantity |
|---|---|---|
| Wire Stripper | - | 1 |
| Cutter | - | 1 |
| Digital Multimeter | - | 1 |
| Nose Pliers | - | 1 |
| Tweezers | - | 1 |