

Psg riser
Scalable OS for 6502/65816
- Size
- 48.3 × 53.3 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 11
- Nets
- 48
- Pads
- 144
- Tracks, vias
- 445, 61
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 5 (file 20171130)
- Created
- 22 Dec 2015
- Updated
- 26 May 2025
Overview
Psg riser is an open-source printed circuit board by zuiko21, from the zuiko21/minimOS repository on GitHub, published under the MIT licence. It is a 2-layer board of 48.3 × 53.3 mm with 11 parts on 48 nets, routed with 445 tracks and 61 vias.
It is built around the 74HC08D, 74HC138 and 74HC574D. Its parts include 4 ICs, 3 resistors, 2 connectors and 1 capacitor.
Main components
374HC08D
SOP-14-40℃~+125℃ 1.5V~4.2V 1.9V、3.7V、5.2V 100mV、400mV 2 27ns@4.5V,50pF 2V~6V 2uA 4 5.2mA 5.2mA 500mV~1.8V 74HC Series AND Gate SOIC-14 Logic Gates ROHSNexperiaLogic Gates74HC138
SOP-160℃~+70℃ 24ns@5.0V,16pF 2V~6V 3/8 5.2mA 5.2mA 5uA 74HC Decoder Reverse function Single Supply SOP-16 Signal Switches, Multiplexers, Decoders ROHSGRSignal Switches, Multiplexers, Decoders74HC574D
SOP-20L-40℃~+125℃ 1 13ns 15ns@6V,50pF 2.7V~6V 20uA 28MHz 5ns 6.5pF 7.8mA 7.8mA 74HC Series 8 D-Type Enable Rising Edge Tri-State SOP-20L Flip Flops ROHSMDDFlip Flops
README
README.mdThis project is under the MIT License, see LICENSE for details.
minimOS
Please note that this doc is OBSOLETE. Read about updated details in the new architecture.md file.
Minimalistic, portable, scalable Operating System for everything from embedded devices to (quasi) full-featured desktop computers!
Purpose
Currently in a VERY early development stage, hopefully will become a common reference platform for deployment of computer-related appliances -- think about embedded systems, like the original intent: an Actual Exposure Time Meter for classic photographic cameras. But by virtue of its modularity and scalability would equally serve to a whole breed of home-made, retro-inspided computers.
Future ports
Initial target is the venerable 65(C)02 and its big brother, the 16-bit enabled 65816 (port known as minimos·16) which will keep compatibility with existing '02 code. But other ports to many CPU architectures are in mind, like the Motorola 68xx / Hitachi 63xx series (minimOS·63, with the interesting 6809/6309 branch as minimOS·69), 680x0 (minimOS·68), 8080/8085/Z80 (minimOS·80), even (God forbid! :-) the commonly used x86 (minimOS·86). I really have little-to-no knowledge about this CPU family, nor about the usual IBM-based PC architecture; hopefully someone will be able to port minimOS without too much of a chore, that would give a very interesting 'breath' to (otherwise useless) older PCs.
Supported architectures
This section has been moved to the hardware section
Parts
11| Qty | Value | Footprint | References |
|---|---|---|---|
| 2 | 3K3 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P2.54mm_Vertical | R1, R3 |
| 1 | 10µ | Capacitor_THT:CP_Radial_D4.0mm_P1.50mm | C1 |
| 1 | 4K7 | Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P2.54mm_Vertical | R2 |
| 1 | 74HC08 | Package_DIP:DIP-14_W7.62mm_Socket | U4 |
| 1 | 74HC138 | Package_DIP:DIP-16_W7.62mm_Socket | U3 |
| 1 | 74HC574 | Package_DIP:DIP-20_W7.62mm_Socket | U2 |
| 1 | CARTRIDGE | Connector_PinSocket_2.54mm:PinSocket_2x18_EDGE | J2 |
| 1 | Durango_ROM | edge_conn:Durango_ROM | J1 |
| 1 | Logo_Open_Hardware_Small | durango:j300 | LOGO1 |
| 1 | SN76489A | Package_DIP:DIP-16_W7.62mm_Socket | U1 |
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Questions
How big is the Psg riser PCB?
It measures 48.3 × 53.3 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Psg riser use?
11 parts, built around the 74HC08D, 74HC138 and 74HC574D. 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 Psg riser KiCad files?
From the zuiko21/minimOS repository on GitHub, at the commit this page was made from: the board is hard/kicad/durango/cartridges/psg-riser/psg-riser.kicad_pcb. PCBKit opens the board in the browser, with nothing to install.
Can I use the Psg riser design in my own project?
Its repository publishes it under the MIT licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).