ZX80 / ZX81 Emulator for the Raspberry Pi Pico

[Exile]

What a great project!!!!
I think I ll look for an old case. And build up one just to use de Chroma 81 emulation while it's not avaliable since a lot of time...

Thank you. It's great to hear of people using the software. Please post pictures if you build one

I saw a minor detail in the git page. The Space Invaders picture is from the WRX version by Splinter GU https://splintergu.itch.io/space-invaders-for-zx81-wrx not from the Pseudo HRG it makes reference to. As a Space Invaders fan I couldn't let this alone .

A good spot, you are correct! I'll update the Readme in the next few days.

[Paul]

Any intentions to use Pico2?

[Exile]

Any intentions to use Pico2?

I have ordered some pico2 for evaluation. They offer a signifacnt increase in performance over the original pico. The question is how that extra performance can be used to improve the current emulator.

The RP2350B offers extra GPIO which may allow better simultaneous support for embedded keyboards and joysticks, but that is dependent on new hardware boards.

I've just completed an exercise to improve perfromance, so all of the current picozx81 functionality fits well within the constraints of the pico1. The code is on main, I'll create another release in due course.

What extra functionality would people like to see in picozx81?

[Paul]

Full chroma Support for ZX80 (and 81) would be great. I will have to check out the current version and see if everything ZX80 and chroma is already working

And there is much more RAM and FLASH in the Pico2.

You can contact me if you want a Pico2 board with joystick and original keyboard or whatever comes to your mind like realtime clock etc.
I'm happy to make and offer them.
At the moment I am playing with a 2350StampXL which has all 48 iO pins exposed .

[Exile]

Full chroma Support for ZX80 (and 81) would be great. I will have to check out the current version and see if everything ZX80 and chroma is already working

Hopefully the support for Chroma is complete. There were some performance tweaks recently, so please download the uf2 you need from https://github.com/ikjordan/picozx81/tree/main/uf2

As mentioned in the Readme at https://github.com/ikjordan/picozx81?ta ... icomitevga, there will be some colour issues with the PicoMiteVGA board, as this board only has 1 bit for blue and red. Other boards should display all the colours correctly.

Please also explore the new ZX80 emulation. All the programs I have tested have worked, but there is always the possibility of a corner case. As described at https://github.com/ikjordan/picozx81?ta ... -artefacts there is a procedure that has to be followed to run the ZX80 Kong and Pacman Chroma editions.

And there is much more RAM and FLASH in the Pico2

I guess that will allow full emulation of ZXpand+

You can contact me if you want a Pico2 board with joystick and original keyboard

Thank you for the offer of Pico2 hardware. My wishlist for the ultimate 2350 board using 48 GPIO
1. GPIO connects for original keyboard and serial joystick
2. HDMI output, with the output set to pins that support hstx (12 to 19). I've not looked in detail to see if audio can be added to hstx, if not then we would need either PWM line out, or drive the HDMI using PIO, as in the current 2040 boards.
3. An audio in would also be interesting. There are circuits for that discussed at https://github.com/fruit-bat/pico-zxspe ... updates.md Keeping hardware compatibility with fruit-bat's spectrum emulator is nice - and allows people to run ZX80, ZX81 and Spectrum emulation on the same hardware.

[Exile]

There is a new release of picozx81 at https://github.com/ikjordan/picozx81

1. This improves CPU performance in some corner cases
2. More importantly it also supports the Pico2 (i.e. the RP2350).

• The RP2350 has been tested with the Pimoroni and Olimex carrier boards.

• When running on the Pico2 there is a great deal of spare CPU and memory!

3. @bola_dor I've also updated the Readme to credit the right space invaders game

This release requires at least version 2.0 of the Raspberry Pi Pico SDK to build. If you intend to build from source please do consult the Readme, as the build instructions have changed due to the support for both chips.

If you do not wish to build the code yourself, then pre-built uf2 files are available at https://github.com/ikjordan/picozx81/re ... tag/v2.0.0 for all supported boards. The original Pico and Pico2 require different uf2 files. The uf2 names now include the name of the chip they have been built for (either rp2040 or rp2350).