MMPC Model 10/20  (250-1640/41)     Interrupts         Faxback Doc. # 2541

Interrupt Assignments
┌──────────────────────────────────────┬─────────┬────────────┐
│Device/Circuit                        │Interrupt│Status      │
├──────────────────────────────────────┼─────────┼────────────┤
│8254 counter timer                    │IRQ0     │Unavailable │
│PS/2 keyboard                         │IRQ1     │Unavailable │
│Secondary interrupt controller cascade│IRQ2     │Unavailable │
│Serial port (COM2)                    │IRQ3     │Reserved    │
│Serial port (COM1)                    │IRQ4     │Reserved    │
│Alternate parallel port               │IRQ5     │Available   │
│Diskette drive interface              │IRQ6     │Reserved    │
│Parallel port and audio adapter       │IRQ7     │Reserved    │
│Real-time clock                       │IRQ8     │Reserved    │
│Video vertical retrace (optional)     │IRQ9     │Available   │
│Alternate serial port (COM4)          │IRQ10    │Available   │
│CD-ROM drive interrupt                │IRQ11    │Unavailable │
│PS/2 mouse interrupt                  │IRQ12    │Reserved    │
│Coprocessor                           │IRQ13    │Unavailable │
│IDE hard drive interface              │IRQ14    │Reserved    │
│Unused                                │IRQ15    │Available   │
└──────────────────────────────────────┴─────────┴────────────┘
Status key:
Unavailable = used internally; cannot be freed.
Available = unused in system with default configuration.
Reserved = used in system with default configuration; can 
be freed by changing jumper or software settings.



(smc-02/02/94)