Talk:RAMBO-1: Difference between revisions
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m (Reverted edits by 37.59.173.129 (talk) to last revision by Drag) |
(→IRQ related - Hard Drivin': new section) |
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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. --[[User:Drag|Drag]] 03:05, 9 November 2011 (UTC) | 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. --[[User:Drag|Drag]] 03:05, 9 November 2011 (UTC) | ||
== IRQ related - Hard Drivin' == | |||
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. --[[User:Zepper|Zepper]] ([[User talk:Zepper|talk]]) 21:14, 11 January 2014 (MST) | |||
Revision as of 04:14, 12 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)
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)
