Geneve CRU definitions
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/signal means negative logic
| TMS 9901 | |
| 0002 | INTA |
| 0004 | VDP Interrupt |
| 0006 | Joystick (button?) |
| 0008 | Joystick left |
| 000a | Joystick right |
| 000c | Joystick down |
| 000e | Joystick up |
| 0010 | Keyboard Interrupt |
| 0018 | INTB |
| 001a | Real-Time clock interrupt |
| 0024 | Joystick select |
| 002c | Keyboard reset |
| 002e | /VDP wait states |
| 0030 | P-Box reset |
| 0032 | System clock speed |
| 0034 | P-Box pin 18 sense (declared as not used) |
| 0036 | External memory cycle select |
| 0038 | Mouse button 3 |
| 003a | VDP reset |
| Special | |
| 13c0-13fe | Single step |
| TMS9995 | |
| 1ee0 | Decrementer in event counter mode (0=in timer mode) |
| 1ee2 | Enable decrementer |
| 1ee4 | Interrupt level 1 latch |
| 1ee6 | Interrupt level 2 latch |
| 1ee8 | Interrupt level 4 latch |
| 1eea-1eee | not used |
| 1ef0 | Keyboard clock enable |
| 1ef2 | Clear keyboard input register |
| 1ef4 | Geneve mode (/TI mode) |
| 1ef6 | Direct mode (/Mapper mode) |
| 1ef8 | Cartridge rom size (1=8 KiB, 0=16 Kib) |
| 1efa | /Protect 6000 |
| 1efc | /Protect 7000 |
| 1efe | /Add wait state per memory cycle |
| 1fda | Macro Instruction Detect |
The MID flag is set whenever the CPU encounters an unknown opcode. This (together with the interrupt) may be used to implement new "commands" on the application level.