4 replies to this topic

[PacManPlus]

Hi!

I hope someone can help me - can anyone tell me how to read the difficulty switches on the 7800 in 7800 mode? (Example code would be great!) I'm working on something where I need to read both switches. Thanks in advance!

Bob

[Bruce Tomlin]

It works exactly the same as on the 2600.

[PacManPlus]

Thanks Bruce

For some reason I thought it was different...

I think I have a commented Adventure disassembly I can look through to see how they read them.

Thanks again

[Harry_Dodgson]

PacManPlus, on Wed May 11, 2005 7:18 AM, said:

Hi!

I hope someone can help me - can anyone tell me how to read the difficulty switches on the 7800 in 7800 mode?  (Example code would be great!)  I'm working on something where I need to read both switches.  Thanks in advance!

Bob

How about something like this? :-)

BIT Swchb
BVS p0expert
BVC p0amateur
BCS p1expert
BCC p1amateur

[vdub_bobby]

Harry_Dodgson, on Thu May 12, 2005 7:42 AM, said:

PacManPlus, on Wed May 11, 2005 7:18 AM, said:

Hi!

I hope someone can help me - can anyone tell me how to read the difficulty switches on the 7800 in 7800 mode?  (Example code would be great!)  I'm working on something where I need to read both switches.  Thanks in advance!

Bob

How about something like this? :-)

BIT Swchb
BVS p0expert
BVC p0amateur
BCS p1expert
BCC p1amateur

The 'bit' instruction puts bit 7 into the sign flag, not the carry flag!
And also, in that code the last two lines will never be reached.
Try this instead:

   bit SWCHB
   bmi P1Expert
  ;--else P1 novice
   bvs P0ExpertAndP1Novice
  ;--else P0 novice and P1 novice
  ;--code here
   jmp Done
P0ExpertAndP1Novice
  ;--code here
   jmp Done
P1Expert
   bvs P0ExpertAndP1Expert
  ;--else P0 novice and P1 expert
  ;--code here
   jmp Done
P0ExpertAndP1Expert
  ;--code here

Done