Hardware summary

• Z80 @ 3.57 Mhz
• 1k RAM
• MC6847 with 3k VRAM
• AY-3-8910
• Cartridge size limited to 4k

Classic library support

• Native console output
• Native console input
• ANSI vt100 engine
• Generic console
  • Redefinable font
  • UDG support
• Lores graphics (32x16)
• Hires graphics (256x96)
• PSG sound
  • ETracker (SAA tracker)
  • PSG Lib (SN76489)
  • Arkos2 Player (AY)
  • WYZ Player (AY)
  • Vortex tracker (AY)
• One bit sound
• Inkey driver
• Hardware joystick
• File I/O
• Interrupts
• RS232

Compilation

zcc +sv8000 program.c -create-app

Will create a 4k ROM suitable for loading into Mame. Large cartridges can be created using -subtype=32k however loading them isn't support by the Mame emulator

Screenmodes and graphics

The target supports two screen modes:

• Mode 0 text based, 32x16, graphics 32x16, only character codes 32 - 95 are available
• Mode 1 graphical, 32x12, graphics 256x96, supports redefining fonts and UDGs

The screen mode can be changed with the following code:

#include <sys/ioctl.h>

int mode = 1;
console_ioctl(IOCTL_GENCON_SET_MODE, &mode);

Of course, supported multiple screen modes does have an overhead, especially on a machine with restricted memory such as this. If you don't use a mode, it can be excluded from the final binary using the following pragmas: -pragma-define:CLIB_DISABLE_MODE0=1 and -pragma-define:CLIB_DISABLE_MODE1=1

Screenshots

The terminal version of DStar running:

zcc +sv8000 dstar_gencon.c -DUSE_JOYSTICK -DUSE_UDGS -DSWITCH_MODE=1 -pragma-redirect:CRT_FONT=_font_8x8_bbc_system -create-app

Limitations

• 4k isn't much space
• The joystick supports the directions and # as the fire button

Links

• Mame emulator