4 layers90 × 88 mm
Control
AJain9199/AOS16
Table of Contents About The Project Pictures Technical Details Directory Structure To-Do Acknowledgments
129 parts1
4 layers88 × 86 mm
Memory Controller
AJain9199/AOS161Table of Contents About The Project Pictures Technical Details Directory Structure To-Do Acknowledgments
- Size
- 88 × 86 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 70
- Nets
- 77
- Pads
- 373
- Tracks, vias
- 934, 116
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 15 Feb 2025
- Updated
- 7 Nov 2026
Overview
Memory Controller is an open-source printed circuit board by AJain9199, from the AJain9199/AOS16 repository on GitHub. It is a 4-layer board of 88 × 86 mm with 70 parts on 77 nets, routed with 934 tracks and 116 vias.
It is built around the 74AHC1G32GW, 74AHC1G04SE and 71016S12PHG8, with the 74AHC1G08GW among its other parts. Its parts include 20 capacitors, 15 ICs, 6 connectors, 4 resistors and 4 diodes.
Main components
4
74AHC1G32GW
SOT-353-40℃~+125℃ 1 1.5V~3.85V 1.9V、2.9V、3.94V、4.4V 100mV、100mV、100mV、550mV 1uA 2 2V~5.5V 500mV~1.65V 7.5ns@5V,50pF 74AHC Series 8mA 8mA OR Gate Overvoltage-tolerant input SOT-353 Logic Gates ROHSNexperiaLogic Gates74AHC1G04SE
SOT-353-40℃~+125℃ 1 1 1.5V~3.85V 1.9V、2.9V、4.4V 1uA 2V~5.5V 500mV~1.65V 7.5ns@5V,50pF 74AHC 8mA 8mA Noise suppression function Schmitt trigger SOT-353 Inverters ROHSDiodes IncorporatedInverters
71016S12PHG8
TSOPII-44-10.2mmTSOPII-44-10.2mm SRAM ROHSRenesas ElectronicsSRAM74AHC1G08GW
SOT-353-40℃~+125℃ 1 1.5V~3.85V 1.9V~2V、2.9V~3V、3.7V~3.94V、4.4V~4.5V 100mV、360mV~550mV 10nA 2 2V~5.5V 500mV~1.65V 74AHC Series 9.5ns@3.3V,15pF AND Gate Overvoltage-tolerant input StandardCMOS SOT-353 Logic Gates ROHSMDDLogic Gates
README
README.md[blocked]
AOS16
A self-made 16-bit computer.
Table of Contents
About The Project
AOS16 is a self-made 16-bit Reduced Instruction Set Computer (RISC) on PCBs, complete with a homebrew GPU for screen output. It is fully planned, designed and fabricated from scratch. A Turing-complete, Harvard-style computer with a completely custom architecture, at a blistering fast 10MHz.
The project is divided into smaller subsytems on PCBs, designed to interconnect via a central bus.
Features
- 16-bit address and data buses
- Hardware double buffering with parallel CPU and GPU operation
- 10 MHz clock
- 6 general-purpose registers, a stack pointer and a flags register
- 65 Kb of general purpose RAM
- 131 Kb of framebuffer (double buffered, so 65Kb usable)
- 131 Kb of program memory
Why?
This project was a learning effort for me. I started this project wanting to learn more about computer architectures and gain hands-on experience with electrical engineering. Also, building a computer, from scratch, is the coolest project I've seen around. Some inspiration from amazing engineers including Ben Eater and jdh were more than enough to convince me to try my hand at this project.
How's it different?
Most homebrew computers on the internet are 8-bit computers built on breadboards. AOS16 is novel in its capabilities, being a 16-bit computer built on PCBs with a much higher clock speed, with display support directly integrated.
Pictures
A simulation of the computer in Digital displaying the color palette on the screen
GPU displaying the pillars of creation
The Arithmetic Logic Unit in KiCAD
The logic simulation in Digital.
The Reg4x16 PCB
.jpeg)
The Double Buffer PCB
Technical Details
Details about the design decisions, design of the instruction word, etc. can be found in the Design Doc.
Directory Structure
- assembler: Contains the source code for the AOS16 assembler
- sim: Logic simulation files written for Digital
- microcode: Microcode implementations written in MiLa
- tests: some basic tests for ICs and the simulation
- common: basic KiCAD schematics (registers, transceivers) which are shared across subsystems
Each of the remaining folders represents a subsystem, built on a separate PCB. Each folder will contain a KiCAD schematic and PCB file.
To-do
Main Phases of the project:
- Finalize project parameters and design goals
- Hardware:
- Logic Simulation and Design
- PCB Design
- PCB Fabrication & integration
- Software:
- Microcode (with MiLa)
- Assembly language design
- Assembler
- ROM programming software
| Component / Phase | Logic Simulation | PCB Design | Fabrication and Integration |
|---|---|---|---|
| Double Buffer | ✅ | ✅ | ✅ |
| Memory Controller | ✅ | ✅ | ✅ |
| ALU | ✅ | ✅ | ✅ |
| Registers | ✅ | ✅ | ✅ |
| Control Unit | ✅ | ✅ | ✅ |
| Program Counter | ✅ | ✅ | ☐ |
| GPU | ✅ | ✅ | ☐ |
| Main Data Bus | ✅ | ✅ | ☐ |
| Phase Completed | ✅ | ✅ | ☐ |
Acknowledgments
- Ben Eater for his excellent series on the breadboard computer
- jdh for the inspiration
- The Elements of Computing Systems and the accompanying Nand2Tetris course by Shimon Schocken and Noam Nisan
- r/homebrewcomputer and r/PrintedCircuitBoard commmunities for PCB reviews and design checks
- Digital, the logic simulator
Parts
70| Qty | Value | Footprint | References |
|---|---|---|---|
| 16 | TestPoint_Small | TestPoint:TestPoint_Pad_1.0x1.0mm | TP2, TP3, TP4, TP5, TP6, TP7, TP8, TP9, TP10, TP11, TP12, TP13, TP14, TP15, TP16, TP17 |
| 12 | C | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3, C4, C5, C6, C7, C8, C9, C15, C16, C19 |
| 7 | 74AHC1G32 | Package_TO_SOT_SMD:SOT-23-5 | U1, U3, U4, U5, U7, U8, U9 |
| 4 | 0.01uF | Capacitor_SMD:C_0603_1608Metric | C10, C11, C12, C13 |
| 4 | LED | LED_SMD:LED_0603_1608Metric | D1, D2, D3, D4 |
| 4 | MountingHole | MountingHole:MountingHole_4mm | H1, H2, H3, H4 |
| 4 | R | Resistor_SMD:R_0603_1608Metric | R1, R2, R3, R4 |
| 3 | 0.1uF | Capacitor_SMD:C_0603_1608Metric | C14, C17, C18 |
| 3 | 74AHC1G04 | Package_TO_SOT_SMD:SOT-23-5 | U2, U6, U15 |
| 2 | Conn_01x02 | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J2, J6 |
| 2 | Conn_02x15_Odd_Even | Connector_IDC:IDC-Header_2x15_P2.54mm_Vertical | J3, J5 |
| 2 | SST39SF010 | Package_DIP:DIP-32_W15.24mm_Socket | U12, U13 |
| 1 | 71016S12PHG8 | Package_SO:TSOP-II-44_10.16x18.41mm_P0.8mm | U14 |
| 1 | 74AHC1G08 | Package_TO_SOT_SMD:SOT-23-5 | U11 |
| 1 | C | Capacitor_SMD:CP_Elec_5x5.3 | C20 |
| 1 | Conn_01x05 | Connector_PinHeader_2.54mm:PinHeader_1x05_P2.54mm_Vertical | J1 |
| 1 | Conn_02x08_Top_Bottom | Connector_PinHeader_2.54mm:PinHeader_2x08_P2.54mm_Vertical | J4 |
| 1 | SN74AHCT16374DGGR | Package_SO:TSSOP-48_6.1x12.5mm_P0.5mm | U10 |
| 1 | TestPoint | TestPoint:TestPoint_Pad_D1.0mm | TP1 |
Questions
How big is the Memory Controller PCB?
It measures 88 × 86 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Memory Controller use?
70 parts, built around the 74AHC1G32GW, 74AHC1G04SE, 71016S12PHG8 and 74AHC1G08GW. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Memory Controller KiCad files?
From the AJain9199/AOS16 repository on GitHub, at the commit this page was made from: the board is Memory Controller/Memory Controller.kicad_pcb and its schematic ALU/ALU.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Memory Controller design in my own project?
Its repository states no licence, so its author keeps all rights: ask AJain9199 before reusing the design.
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