Basicengine

BASIC Engine PCB

The BASIC Engine is a very low-cost single-board home computer with advanced 2D color graphics and sound capabilities, roughly comparable to late-1980s or early-1990s computers and video game consoles. It can be built at home without special skills or tools and using readily available components for under 10 Euros in parts, or mass-produced for even less.

This repository contains KiCAD schematics and the PCB layout. Gerber files for ordering PCBs can be found in the release section.

Software can be found in the BASIC Engine firmware repository.

Hardware features

• ESP12-E/F module with ESP8266 SoC and 4 MB flash memory
• VS23S010 video controller with 128k RAM and composite video output in PAL or NTSC
• 5-bit PCM sound from I2S controller
• MicroSD card slot
• PS/2 and PS/2-compatible USB keyboard interface
• PlayStation controller port
• PCF8575 I/O extender with 16 GPIO pins
• I2C and SPI busses on I/O expansion connector
• power supplied via Micro-USB socket or pin header
• RCA connectors for video and audio

Components

The BASIC Engine does not use any obsolete components that may be difficult to obtain. Nevertheless, you will have to put in at least three orders to get all required parts.

I would recommend to get the circuit board from JLCPCB or Smart Prototyping, the VS23S010D-L chip from TME, and all other parts from AliExpress. AE usually has the lowest price, and this project is all about the cheap.

You will usually have to order more components than you actually intend to use, because

• they are only offered in larger quantities,
• you may want to save on shipping in case you decide to build more BASIC Engines,
• you are likely to break or lose a few parts while building the device, or
• all of the above.

Note: Unless noted otherwise, all links lead to suppliers and components I have bought myself in the past and that have received the "Good Enough for BASIC Engine" seal of approval. Nevertheless you order at your own risk, and I cannot be held responsible for the quality of the services or products provided to you. I am not affiliated with any of the linked suppliers.

Required components

Not strictly required, but strongly recommended components

Optional components

Programming tools

Used to flash the firmware into the microcontroller module. You only need one set of these.

Ordering the PCB

If you have never had a custom circuit board made, you may find the multitude of options you are presented with on the board house's ordering page confusing. The good news is that you do not have to worry about most of them, because they have been set to reasonable defaults already. If you order with JLCPCB or Smart Prototyping using the links above, all you have to do is upload the ZIP file containing the Gerber files that you can find in the release section and specify the dimensions of the board (85x56 mm). All other options can be left as is.

(Just to be on safe side: At the time of writing these options were: 2 layers, 1.6 mm thickness, HASL with lead, 1oz copper weight, material FR4.)

Assembling the BASIC Engine

Even though it uses some small-pitch components, the BASIC Engine has been designed to be easy to assemble.

Click on the thumbnail below to watch a one-hour silent video showing how to build it using a soldering iron, a heat gun, tweezers, solder wire and side cutters, without fancy tools, mad soldering skills and with only a minimal amount of patience:

PCB Errata

Revision 2 of the PCB contains one error:

• R6 value is given as "22R", should be "75R".

Revision 1 of the PCB contains two errors:

• R6 value is given as "22R", should be "75R".
• C3 and C4 values are given as "10p", should be "56p".