ZX Spectrum emulator using Ras Pi pico with 5cm screen
MIT License
It's been 40 years... I still remember the computery smell when I unboxed mine at Xmas (I think 1983)
So for old times' sake here's a ZX Spectrum emulator for the Raspberry Pi pico, using:
Requires pico-sdk (and its dependencies e.g. tinyUSB...), plus the pimoroni-pico libraries. In the repo root:
Ensure tinyUSB sources are present in the lib
subdir of the SDK (extract or symlink to a release here, or use git submodules), e.g.
cd pico-sdk-1.5.1/lib
rmdir tinyusb # will be empty initially
ln -s ../../tinyusb-0.14.0 tinyusb
Using tinyusb 0.15 or above results in a linker error that I don't know how to fix:
[100%] Linking CXX executable picozxspectrum.elf
/usr/lib/gcc/arm-none-eabi/10.3.1/../../../arm-none-eabi/bin/ld: picozxspectrum.elf section `.bss' will not fit in region `RAM'
/usr/lib/gcc/arm-none-eabi/10.3.1/../../../arm-none-eabi/bin/ld: region RAM overflowed
/usr/lib/gcc/arm-none-eabi/10.3.1/../../../arm-none-eabi/bin/ld: section .stack1_dummy VMA [0000000020040000,00000000200407ff] overlaps section .bss VMA [0000000020001828,000000002004005f]
/usr/lib/gcc/arm-none-eabi/10.3.1/../../../arm-none-eabi/bin/ld: region `RAM' overflowed by 96 bytes
collect2: error: ld returned 1 exit status
make[2]: *** [CMakeFiles/picozxspectrum.dir/build.make:1447: picozxspectrum.elf] Error 1
make[1]: *** [CMakeFiles/Makefile2:1541: CMakeFiles/picozxspectrum.dir/all] Error 2
make: *** [Makefile:91: all] Error 2
Symlink Pico SDK and Pimoroni Pico:
ln -s ../pico-sdk-1.5.1 pico-sdk # adjust version and location as necessary
ln -s pico-sdk/external/pico_sdk_import.cmake
ln -s ../pimoroni-pico # adjust to wherever you cloned it to
mkdir -p build && cd build
cmake -DPICO_SDK=../pico_sdk ..
make -j
Still in the build directory:
cp picozxspectrum.uf2 /media/$USER/RPI-RP2/
You should see at this point a blank screen with the LED bright white.
Interaction requires a (rudimentary) keyboard driver written in python and depends on pyserial and pynput. It can also load an image (Z80 or SNA) on startup:
python zx.py [image]
Keys map closely to the ZX Spectrum keyboard (below), with LShift
as caps shift, RCtrl
is symbol shift. LShift+RCtrl
enters extended mode. Various unmapped keys also work, such as Backspace
and the arrow keys which emulate caps-shifted 0,5,6,7,8 respectively.
PrtScr
Home
triggers a screenshot save (png format)
Ins
triggers an image save (registers and RAM in Z80 format)
Del
or the screen's X
button resets the device to the last image loaded/saved, or ZX basic.
Esc
followed by Ctrl+C
exits the keyboard listener.
Much of the C and C++ source code originates from: https://github.com/Jean-MarcHarvengt/MCUME. Copyright notices, where present, have been preserved.
These were also very useful: http://www.breakintoprogram.co.uk/computers/zx-spectrum. https://github.com/fruit-bat/pico-zxspectrum
Keyboard layout from https://dotneteer.github.io/spectnetide/getting-started/use-keyboard-tool