Hol-1 8-bit CPU - RAM board
About the Hol-1 8-bit CPU - RAM board
Hol-1 8-bit CPU - RAM 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 22 components from 10 distinct parts.
Other key parts include the 74LS139, 74LS189, 74LS04 and 74LS245. By type, the board carries 12 ICs, 5 capacitors, 4 connectors and 1 jumper.
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 8-bit CPU - RAM board
Hol-1 8-bit CPU - RAM board bill of materials (BOM)
22 components, 10 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 74LS139 | DIP-16 | U1 |
| 8 | 74LS189 | DIP-16 | U2, U3, U4, U5, U6, U7, U8, U9 |
| 2 | 74LS04 | DIP-14 | U10, U11 |
| 1 | 74LS245 | DIP-20 | U12 |
| 1 | ADDRESS PORT | pin_array_4x2 | P1 |
| 1 | DATA PORT | pin_array_4x2 | P2 |
| 1 | DATA BUS | pin_array_8x2 | P3 |
| 1 | Power | PIN_ARRAY_2X1 | P4 |
| 1 | Blinkenlights | SIL-9 | JP1 |
| 5 | 100nF | C1 | C1, C2, C3, C4, C5 |
Hol-1 8-bit CPU - RAM 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.
- LayoutRAM/Hol-1-RAM.kicad_pcb
- SchematicRAM/Hol-1-RAM.kicad_sch
Hol-1 8-bit CPU - RAM board: common questions
How big is the Hol-1 8-bit CPU - RAM board?
The Hol-1 8-bit CPU - RAM 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 8-bit CPU - RAM board?
22 components, from 10 distinct parts. The full bill of materials is listed on this page.
Where can I download the Hol-1 8-bit CPU - RAM 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 8-bit CPU - RAM 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.
