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hardware:interrupts [2016/06/11 21:56] ex_writer [Automatic Interrupts (ACTINT)] |
hardware:interrupts [2016/06/11 22:17] (current) ex_writer [Automatic Interrupts (ACTINT)] |
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| ===== Automatic Interrupts (ACTINT) ===== | ===== Automatic Interrupts (ACTINT) ===== | ||
| - | <WRAP todo>To be written...</WRAP> | + | <WRAP todo>Test and clarify</WRAP> |
| The Bally Arcade system ROM provides an "automatic" interrupt service via the [[system routines:interrupt scheduler#ACTINT]] system routine. | The Bally Arcade system ROM provides an "automatic" interrupt service via the [[system routines:interrupt scheduler#ACTINT]] system routine. | ||
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| <code z80> | <code z80> | ||
| + | MACTIN: | ||
| DI ; MAKE SURE INTERRUPT IS DISABLED | DI ; MAKE SURE INTERRUPT IS DISABLED | ||
| PUSH AF | PUSH AF | ||
| Line 144: | Line 145: | ||
| </code> | </code> | ||
| + | ACTIN does the following: | ||
| + | * Sets Z80 interrupt mode 2 (IM2) | ||
| + | * Sets I register and INFBK to vector to ITAB on interrupt (which calls MACTIN) | ||
| + | * Sets INLIN to $C8 (i.e., line 100) | ||
| + | * Calls TIMEZ (updates game timer, blackout timer, and music processor) | ||
| + | * Calls TIMEY (decrements counter-timers CT0–CT3) | ||
| ===== Screen Interrupt Examples ===== | ===== Screen Interrupt Examples ===== | ||
