PicoPOST

From The Retro Web Wiki
PicoPOST logo

What is PicoPOST?

The PicoPOST is an open-source hardware project focused on making it easy to diagnose issues on retro PCs equipped with an ISA slot.

It's our attempt to re-invent the classic PC “POST card”, and bring with it many new features including:

  • POST code readouts at many different ports (not just 80h)
    • 80h - standard
    • 90h - IBM PS/2
    • 84h - Compaq
    • 300h - EISA
    • 378h - Olivetti
    • more?
  • Voltage readouts for 12V, -12V and 5V rails
  • Full bus activity trace
  • Bus clock readout

PicoPOST is still under active development, with some features not yet implemented

Hardware Info

PicoPOST was designed with three goals in mind:

  • Affordable
  • Easy to build
  • Versatile

This means a simple BOM (Bill of Materials), with no exotic parts, and no parts that can't be hand soldered.

Pixel art of the Raspberry Pi Pico

The core of the platform (and its namesake) is the Raspberry Pi Pico, a small and affordable microcontroller board using the RPiF's own RP2040 silicon, which provides two Cortex-M0+ cores at 133Mhz (easily overclockable to 266Mhz or above) and PIO engines that can read or write data at a very rapid rate.

Build guide

A quick build guide can be downloaded here.

More info Soon!

Remote control configuration

The remote control PCB features a 6-pad jumper block (J5), which is used to specify your current hardware configuration at runtime.

Current firmware (v0.4.1, at the time of writing) supports I2C monochrome OLED displays, based either on the SSD1306 or SH1106 controllers. The two are not 100% compatible and require a slightly different command set. You should set J5-1 according to the display type you're using.

Graphical elements have been tuned to adapt dynamically to the set display height, but no extensive testing has been performed using the 128x64 variants. While technically it should work, we recommend using a 128x32 display instead. This setting can be changed using J5-2. 128px tall or 96px wide displays are not supported.

Depending on the specific display assembly, home coordinates (0,0) might be in the "wrong spot". If your PicoPOST remote shows its interface upside down, you can use J5-3 to flip the drawing routine 180°.

Jumper settings for J5
Pads Open Closed
1 - Display type SSD1306 SH1106
2 - Display size 128x32 128x64
3 - Flip display Normal 180°

User's guide

Coming Soon!

Low-level firmware structure

More detailed, developer-oriented firmware documentation can be found in the dedicated firmware development page.

External links