INTERUP.TXT

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 ******** 68000 AND 68901 INTERRUPT VECTOR TABLE *******
 
 Note: on the ST, interrupt levels 1, 3, and 5 are not wired 
 (a pin of the 68000 is not connected).
 
 The vectors associated with the MFP 68901 are placed in the user interrupt vector area.
 All MFP interrupts are handled by the 68000 as being at level 6.
 
 The internal priority order of the MFP ranges from 15 (max priority) to 0
 (min priority). This order is also reflected in the bits in all
 MFP registers, thus providing a simple correspondence to remember
 between the bit position used to set an interrupt and its priority level.
 
 +------------------------------------------------------------------------+
 *   Level          Address       Description                             *
 +------------------------------------------------------------------------+
 *      7             $7C           NMI (Reset)                           *
 *      6             $78           MFP 68901                             *
 *      5             $74                                                 *
 *      4             $70           VBL, frame return                     *
 *      3             $6C                                                 *
 *      2             $68           HBL, line return                      *
 *      1             $64                                                 *
 *------------------------------------------------------------------------+
 * Level 6: MFP 68901                                                     *
 *                                                                        *
 *     15            $13C      Monochrome monitor detection               *
 *     14            $138      RS232 ring indicator                       *
 *     13            $134      Timer A (available)                        *
 *     12            $130      RS232 receive buffer full                  *
 *     11            $12C      RS232 receive error                        *
 *     10            $128      RS232 transmit buffer empty                *
 *      9            $124      RS232 transmit error                       *
 *      8            $120      Timer B, Horizontal interrupt counter      *
 *      7            $11C      Disk and DMA controller                    *
 *      6            $118      ACIA 6850  ( MIDI and Keyboard )           *
 *      5            $114      Timer C ( 200 Hz system clock )            *
 *      4            $110      Timer D ( RS232 clock )                    *
 *      3            $10C      Video controller ( operation complete ).   *
 *      2            $108      Serial I/O CTS                             *
 *      1            $104      Serial I/O DCD                             *
 *      0            $100      Parallel interface BUSY line               *
 *                                                                        *
 +------------------------------------------------------------------------+

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