PICO9918 v0.3

A drop-in replacement for a classic TMS9918A VDP using a Raspberry Pi Pico.

The TMS9918A emulation is handled by my vrEmuTms9918 library which is included as a submodule here

Supported devices

This is a list of devices the PICO9918 has been tested and confirmed to work on.

• Texas Instruments TI-99/4A (NTSC and PAL)
• Texas Instruments TI-99/4QI
• Dan Werner TI-99/22
• ColecoVision (NTSC and PAL)
• Coleco ADAM (NTSC)
• AtariBits CV-NUC+
• Memotech MTX500
• MSX
• Casio MX-10
• Casio PV-7
• Casio PV-16
• Gradiente Expert XP-800
• National CF-2700
• Sharp HB-8000
• Sony HB-75
• Toshiba HX-21
• Yamaha YIS-503
• NABU Personal Computer
• Powertran Cortex
• Sega SG-1000 / SC-3000
• Sord M5
• Tomy Pyūta / Tomy Tutor
• Tomy Pyūta Jr

If you have tested the PICO9918 on any other device, please let me know and I'll happily update this list. :)

Hardware

There are two main variants of the hardware.

v1.2 (formerly v1.1, v1.0 and v0.4)

PICO9918 v1.2 is the single board version which doesn't require a piggy-backed Pi Pico. This is the version you can currently buy pre-assembled from Tindie.

v0.3

v0.3 is relatively cheap and easy to build, schematic and gerbers are available. This version makes use of an external Pi Pico module piggy-backed onto the PICO9918 PCB.

Firmware

If you're not interested in building the firmware yourself, you'll find the latest firmware in the Releases.

To install, just hold the 'BOOTSEL' (or 'BOOT') button while plugging the Pico into a PC, then drag the pico9918.uf2 file on to the new USB drive which should have the volume label RPI-RP2. The Pico will restart (and disconnect) automatically.

Development environment

To set up your development environment for the Raspberry Pi Pico, follow the Raspberry Pi C/C++ SDK Setup instructions. The latest PICO9918 source can be configured and built using the official Raspberry Pi Pico VSCode plugin.

Windows

The build system expects python3 to be available. If you have installed Python 3 outside of the Microsoft Store, you may need to alias your Python executable.

You can do this from an elevated (Administator) command prompt in your python directory e.g. C:\Program Files\Python310\ by creating a symlink with the command: mklink python3.exe python.exe.

The custom python build tools are used to convert binary data (images) into code. These also require the pillow library - (Installation instructions for pillow)

Discussion

For all the latest news and discussion on the PICO9918, you can follow this AtariAge thread

Purchasing options

Fully assembled and tested PICO9918 v1.2s are available on my Tindie store:

Videos

Initial "raw" videos recorded in the moments following the first boot on my TI-99/4A.

These videos are showing the v0.2 hardware with an external Pi Pico providing the required GROMCLK signal to the TI-99. This signal has been added to v0.3. I'm still waiting on v0.3 boards to arrive.

It freaking works!

Don't mess with Texas!

80 column mode

And now v0.4 - the single board version:

v0.4 prototype working!

F18A mode development preview

Licensing

Hardware

The hardware design files in this repository are licensed under the CERN-OHL-S. See LICENSE_HARDWARE.md for details.

Firmware

The firmware code in this repository is licensed under the MIT License. See LICENSE_FIRMWARE.md for details.