Talk:RAMBO-1: Difference between revisions
From NESdev Wiki
Jump to navigationJump to search
(→IRQ related - Hard Drivin': new section) |
|||
| Line 2: | Line 2: | ||
== IRQ related - Hard Drivin' == | == IRQ related - Hard Drivin' == | ||
Suggested changes for the Mapper64 IRQ. It makes Hard Drivin' to work fine. No games are affected with this change. | |||
Next CPU clock: | Next CPU clock: | ||
Revision as of 00:29, 13 January 2014
As for the 2mb PRG, I'm not sure if the cart actually supports that much ROM, but the PRG registers apparently are 8 bits, and 8kb * $100 = 2048kb = 2mb. --Drag 03:05, 9 November 2011 (UTC)
Suggested changes for the Mapper64 IRQ. It makes Hard Drivin' to work fine. No games are affected with this change.
Next CPU clock:
- IF $C001 was written to after previous clock
- reload IRQ counter with IRQ Reload value PLUS ONE
- ELSE IF IRQ counter is 0
- reload IRQ counter with IRQ Reload value
When the IRQ is clocked:
- Decrement IRQ counter by 1
- IF IRQ counter is now 0 AND IRQs are enabled
- wait one M2 cycle, then trigger IRQ
Hard Drivin' works. --Zepper (talk) 21:14, 11 January 2014 (MST)
