Talk:RAMBO-1

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)

IRQ related - Hard Drivin'

Suggested changes for the Mapper64 IRQ. It makes Hard Drivin' to work fine. No other games are affected with this change. Every cycle on 6502 is either a read or a write cycle. So, you update the IRQ counter in the next CPU cycle:

• 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 by the mapper (in scanline or cycle mode):

• • 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) 17:57, 14 January 2014 (MST)