Instruction
About the Instruction PCB
Instruction is an open source PCB design by jes, published on GitHub under the Unlicense license. It is a 2-layer board measuring 237.5 × 102.9 mm, with 110 components from 16 distinct parts.
Other key parts include the 28C16, 74LS04, 74LS08, 74LS00 and 74LS32. By type, the board carries 55 resistors, 22 ICs, 22 capacitors, 6 jumpers and 5 connectors.
From the project
A homebrew 16-bit CPU with a homebrew Unix-like-ish operating system.
SCAMP is my homebrew 16-bit CPU. It stands for something like "Simple Computing and Arithmetic Microcoded Processor".
The CPU is very primitive. It doesn't support interrupts, and has no MMU, and no concept of privilege levels. It currently runs at 1 MHz, above that the CompactFlash interface falls over. It runs a homebrew operating system, with a homebrew programming language and compiler, and can self-host the kernel and all of the system utilities. The environment tastes a bit like an early Unix, but works like CP/M. I used the computer to complete almost all of Advent of Code 2021.
Main components on the Instruction
Instruction bill of materials (BOM)
110 components, 16 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 2 | 28C16 | DIP-24_W15.24mm_Socket | U1, U2 |
| 1 | 74LS04 | DIP-14_W7.62mm_Socket | U3 |
| 2 | 74LS08 | DIP-14_W7.62mm_Socket | U4, U6 |
| 2 | 74LS00 | DIP-14_W7.62mm_Socket | U5, U17 |
| 1 | 74LS32 | DIP-14_W7.62mm_Socket | U7 |
| 2 | 74LS138 | DIP-16_W7.62mm_Socket | U8, U9 |
| 5 | 74LS161 | DIP-16_W7.62mm_Socket | U10, U13, U14, U15, U16 |
| 5 | 74LS244 | DIP-20_W7.62mm_Socket | U11, U12, U18, U19, U20 |
| 2 | 74LS377 | DIP-20_W7.62mm_Socket | U21, U22 |
| 1 | Conn_02x30_Counter_Clockwise | PinSocket_2x30_P2.54mm_Horizontal | J1 |
| 2 | Conn_01x17_Male | PinHeader_1x17_P2.54mm_Vertical | J2, J3 |
| 1 | Conn_01x10_Male | PinHeader_1x10_P2.54mm_Vertical | J4 |
| 1 | Conn_01x15_Male | PinHeader_1x15_P2.54mm_Vertical | J5 |
| 6 | Jumper_NO_Small | PinHeader_1x02_P2.54mm_Vertical | JP1, JP2, JP3, JP4, JP5, JP6 |
| 22 | C | C_Disc_D5.0mm_W2.5mm_P2.50mm | C1, C2, C3, C4, C5, C6, C7, C8 +14 |
| 55 | R | R_Axial_DIN0207_L6.3mm_D2.5mm_P7.62mm_Horizontal | R1, R2, R3, R4, R5, R6, R7, R8 +47 |
Instruction design files
The KiCad project lives in the jes/scamp-cpu repository on GitHub; these links point at the commit this page was built from.
Instruction: common questions
How big is the Instruction PCB?
The Instruction measures 237.5 × 102.9 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Instruction?
110 components, from 16 distinct parts. The full bill of materials is listed on this page.
Where can I download the Instruction design files?
From the jes/scamp-cpu repository on GitHub, which has the KiCad layout; the links under Design files point to each one.
Can I use the Instruction design in my own project?
Yes, under the terms of its Unlicense license, which jes chose for the repository.
