HOL-1 TTL CPU - Clock board
About the HOL-1 TTL CPU - Clock board
HOL-1 TTL CPU - Clock board is an open source PCB design by agben, published on GitHub. It is a 2-layer board measuring 109.2 × 78.7 mm, with 30 components from 16 distinct parts.
Other key parts include the NE555, 74LS00 and 74LS04. By type, the board carries 7 capacitors, 7 resistors, 6 connectors, 5 ICs, 2 switches and 2 diodes.
From the project
Homebrew 8-bit TTL CPU
HOL-1 a homebrew 8-bit TTL CPU --- HOL-1 is a TTL based 8-bit CPU based on the 'simple as possible' breadboard design by Ben Eater https://eater.net/8bit/
As well as adding my own modifications to each module of this CPU. i.e. - more memory - more registers - more ALU functions - more commands (assembler code to follow)
The main change is that HOL-1 is designed for permanent construction using common 8cm x 12cm double-sided perfboards.
Main components on the HOL-1 TTL CPU - Clock board
HOL-1 TTL CPU - Clock board bill of materials (BOM)
30 components, 16 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 3 | NE555 | DIP-8__300 | U1, U2, U3 |
| 1 | 74LS00 | DIP-14 | U4 |
| 1 | 74LS04 | DIP-14 | U5 |
| 4 | CONN_2 | PIN_ARRAY_2X1 | P1, P4, P5, P6 |
| 2 | CONN_1 | PIN_ARRAY_1 | P2, P3 |
| 1 | 1MΩ | RV2X4 | RV1 |
| 1 | SW_PUSH | SW_PUSH_SMALL | SW1 |
| 1 | SPDT | MICROSWITCH_SPST | SW2 |
| 2 | LED | LED-5MM | D1, D2 |
| 1 | 1uF | EC2v | C1 |
| 3 | 100nF | C1 | C2, C6, C7 |
| 2 | 10nF | C2 | C3, C4 |
| 1 | 100nF | C2 | C5 |
| 5 | 1kΩ | R4 | R1, R2, R4, R6, R7 |
| 1 | 220Ω | R4 | R3 |
| 1 | 1MΩ | R4 | R5 |
HOL-1 TTL CPU - Clock board design files
The KiCad project lives in the agben/Hol-1 repository on GitHub; these links point at the commit this page was built from.
- LayoutClock/Hol-1-Clock.kicad_pcb
- SchematicClock/Hol-1-Clock.kicad_sch
HOL-1 TTL CPU - Clock board: common questions
How big is the HOL-1 TTL CPU - Clock board?
The HOL-1 TTL CPU - Clock board measures 109.2 × 78.7 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the HOL-1 TTL CPU - Clock board?
30 components, from 16 distinct parts. The full bill of materials is listed on this page.
Where can I download the HOL-1 TTL CPU - Clock board design files?
From the agben/Hol-1 repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the HOL-1 TTL CPU - Clock board design in my own project?
The repository has no license, so all rights stay with agben. Use it as a reference, and ask the author before reusing the design.
