Instruction Decoder ROM Board
About the Instruction Decoder ROM Board
Instruction Decoder ROM Board is an open source PCB design by DragonMinded, published on GitHub. It is a 2-layer board measuring 111.1 × 99.1 mm, with 173 components from 15 distinct parts.
By type, the board carries 143 transistors, 16 resistors, 12 connectors and 2 capacitors.
From the project
Hardware and software files for the MiniDragon CPU.
Schematics, hardware simulator and software files for the MiniDragon CPU. This is a from-scratch CPU that I designed and am implementing using transistors, capacitors, resistors and diodes. The goal is to make an 8-bit CPU that could be used for general-purpose computing. There are a lot of toy instruction sets floating around on the web. I chose instead to design my own, loosely based off of the PDP and 6502. It is a single accumulator design with a pair of 16-bit stack pointers and a pair of temporary 8-bit registers. Instructions are 8 bits, operands are 8 bits from memory, temporary…
Instruction Decoder ROM Board bill of materials (BOM)
173 components, 15 distinct parts.
| Qty | Part | Footprint | Refs |
|---|---|---|---|
| 143 | 2N2222 | TO-92_Inline | Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8 +135 |
| 1 | EN | PinHeader_1x01_P2.54mm_Vertical | J1 |
| 1 | D0 | PinHeader_1x01_P2.54mm_Vertical | J2 |
| 3 | Power | PinHeader_1x02_P2.54mm_Vertical | J3, J4, J5 |
| 1 | D1 | PinHeader_1x01_P2.54mm_Vertical | J6 |
| 1 | BIT_4_CONFIG | PinHeader_2x32_P2.54mm_Vertical | J7 |
| 1 | MICROCODE_OUTPUT | PinHeader_1x32_P2.54mm_Vertical | J8 |
| 1 | BIT_3_CONFIG | PinHeader_2x32_P2.54mm_Vertical | J9 |
| 1 | BIT_2_CONFIG | PinHeader_2x32_P2.54mm_Vertical | J10 |
| 1 | BIT_1_CONFIG | PinHeader_2x32_P2.54mm_Vertical | J11 |
| 1 | MICROCODE_PASSTHROUGH | PinHeader_1x32_P2.54mm_Vertical | J12 |
| 2 | 0.1uF | C_Disc_D4.3mm_W1.9mm_P5.00mm | C1, C2 |
| 9 | 10K | R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R1, R2, R3, R4, R5, R9, R10, R11 +1 |
| 3 | 1K | R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R6, R7, R8 |
| 4 | 0 | R_Axial_DIN0309_L9.0mm_D3.2mm_P12.70mm_Horizontal | R13, R14, R15, R16 |
Instruction Decoder ROM Board design files
The KiCad project lives in the DragonMinded/minidragon repository on GitHub; these links point at the commit this page was built from.
Instruction Decoder ROM Board: common questions
How big is the Instruction Decoder ROM Board?
The Instruction Decoder ROM Board measures 111.1 × 99.1 mm, has 2 copper layers and is 1.6 mm thick.
How many components are on the Instruction Decoder ROM Board?
173 components, from 15 distinct parts. The full bill of materials is listed on this page.
Where can I download the Instruction Decoder ROM Board design files?
From the DragonMinded/minidragon repository on GitHub, which has the KiCad layout and the schematic; the links under Design files point to each one.
Can I use the Instruction Decoder ROM Board design in my own project?
The repository has no license, so all rights stay with DragonMinded. Use it as a reference, and ask the author before reusing the design.
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