Improved ZX80 Support

Release with improved ZX80 support

Full emulation of ZX81 and ZX80 with 1kB to 56kB RAM
Sound, pseudo HiRes, WRX, UDG, CHAR$128, M1NOT
50Hz and 50.6Hz 576p; 60Hz 480p
No O/S, sub second boot time, full screen
HDMI and VGA
Sound over HDMI or audio socket
Configure for European or US emulated TV
Frame and interlace synchronisation
Optional ZX81 Big Bang ROM
Tested against large set of software (see Readme)
Joystick and ZX80/81 USB keyboard support
Full screen configuration menus using ZX81 and ZX80 fonts
Pre-built uf2 for 4 commercial boards
Example configuration to copy to micro SD Card

Additions over previous release

Optionally configure ZX80 Save file name using REM statement
Optionally enter ZX80 Save file name using menu
Use ZX80 font in menus when emulating a ZX80
Bug fixes, including:

• Issue with ACB stereo when channel C not used
• Display of long file names in menus
• Centring text in menus

Updated Readme