I got to the bottom of the “PRINT ERROR”; it thought that it had a serial port attached and tried to talk to it. I’ve currently set that so that it looks like the chip is missing, which has got rid of the error. I *might* do something with it later on.

I’ve re-designed a lot of the architecture, it now uses a table to define the hardware:

device_configuration_t system_devices[] =
{
{ keyboard_initialise, NULL, slot_microtan, 0xbff0, 0x0000, "keyboard" },
{ display_initialise, NULL, slot_microtan, 0x0200, 0xbff0, "main display" },
{ display_initialise, NULL, slot_0, 0x8000, 0x0000, "red" },
{ display_initialise, NULL, slot_1, 0x8000, 0x0000, "green" },
{ display_initialise, NULL, slot_2, 0x8000, 0x0000, "blue" },
{ display_initialise, NULL, slot_3, 0x8000, 0x0000, "intensity" },
{ via_6522_initialise, via_6522_reset, slot_tanex, 0xbfc0, 0x0000, NULL },
{ via_6522_initialise, via_6522_reset, slot_tanex, 0xbfe0, 0x0000, NULL },
{ serial_initialise, serial_reset, slot_tanex, 0xbfd0, 0xbfd3, NULL },
{ eprom_initialise, NULL, slot_microtan, 0xc000, 0x0000, "microtan.rom" },
{ cpu_6502_initialise, cpu_6502_reset, slot_microtan, 0x0000, 0x0000, NULL },
{ NULL, NULL, 0, 0, 0, NULL }
};

I’ve mapped the cursor keys, left shift, left ctrl and space keys to bits on the first 6522’s A port, which is where I used to plug in a joystick to play most games, and that works. I’ve done similar with the hex-keypad (Berzerk uses that). So in hex keypad mode, it just maps those keys to buttons on the keypad in a similar arrangement.

I’ve got to do the AY8910 next, but I got a bit sidetracked by working on a “GPU”. The hi-res graphics are very slow to use on the Microtan, so I’m working on fixing that with a extended hi-res graphics “card”.

This shows the Computing Today/ Everday Electronics International Space Invaders game, and some basic help.