Alu back
About the Alu back PCB
Alu back is an open source PCB design by Velko, published on GitHub under the MIT license. It is a 2-layer board measuring 132.1 × 114.3 mm, with 26 components from 22 distinct parts.
Other key parts include the Register A, Register B, Register C, Register D and Add/Sub. By type, the board carries 13 ICs, 8 connectors and 5 capacitors.
It belongs with the retro computing designs in this gallery.
From the project
Homebrew 8-bit CPU
After watching [series of videos][eater-net-8bit] by Ben Eater building an 8-bit computer from scratch, I was hooked. Various thoughts for improvements and experiments was running through my mind. But first I have to build one. Improvements will come later. Whom am I kidding? I'll never be able to build an exact replica, I'll incorporate improvements as I go.
Main components on the Alu back
Alu back bill of materials (BOM)
26 components, 22 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | Register A | Register_board | U1 |
| 1 | Register B | Register_board | U2 |
| 1 | Register C | Register_board | U3 |
| 1 | Register D | Register_board | U4 |
| 1 | Add/Sub | Register_board | U5 |
| 1 | And/Or | Register_board | U6 |
| 1 | Xor/Not | Register_board | U7 |
| 1 | Shift/Swap | Register_board | U8 |
| 1 | Flags | Flags_board | U9 |
| 1 | 74HC125 | SOIC-14_3.9x8.7mm_P1.27mm | U10 |
| 1 | 74HC245 | SO-20_12.8x7.5mm_P1.27mm | U11 |
| 2 | 74HC138 | SOIC-16_3.9x9.9mm_P1.27mm | U12, U13 |
| 1 | SYNC | PinSocket_1x04_P2.54mm_Vertical | J1 |
| 1 | BUS | PinSocket_1x08_P2.54mm_Vertical | J2 |
| 1 | FLAGS | PinSocket_1x04_P2.54mm_Vertical | J3 |
| 1 | OUT | PinSocket_1x08_P2.54mm_Vertical | J4 |
| 1 | FCTL | PinSocket_1x04_P2.54mm_Vertical | J5 |
| 1 | LOAD | PinSocket_1x04_P2.54mm_Vertical | J6 |
| 1 | ARGS | PinSocket_1x08_P2.54mm_Vertical | J7 |
| 1 | POWER | PinSocket_2x02_P2.54mm_Vertical | J8 |
Show 2 more
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 1 | 10uF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C1 |
| 4 | 100nF | C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C2, C3, C4, C5 |
Alu back design files
The KiCad project lives in the Velko/8-bit-CPU repository on GitHub; these links point at the commit this page was built from.
Alu back: common questions
How big is the Alu back PCB?
The Alu back measures 132.1 × 114.3 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Alu back?
26 components, from 22 distinct parts. The full bill of materials is listed on this page.
Where can I download the Alu back design files?
From the Velko/8-bit-CPU repository on GitHub, which has the KiCad layout; the links under Design files point to each one.
Can I use the Alu back design in my own project?
Yes, under the terms of its MIT license, which Velko chose for the repository.
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