LZ: Interrupts

[Prev][Next][Index][Thread]

LZ: Interrupts

I have been trying to get some code to run under int 2, but without 
success.  I found out that I have to use IM 2, and I am trying to get 
the interrupts to jump to a spot in my program instead of having the 
interrupt jump to some spot in GRAPH_MEM.  I don't know why it 
doesn't work because my program is right after ZShell in mem, and I 
have loaded $92 to the IV and that's where my $88's start.  I wasn't 
sure if the problem was with the $88's so I changed them to 00's but 
it still didn't work.  I have not changed the interrupt routine at 
all, so it should work.  I think that the problem may be with the 
$88's or the $00's.  How does the CPU know what address to jump to in 
IM 2?  Does it take the IV as the MSB and then use the value on the 
data bus as the LSB (in my case it'd be $92xx, and I have 256 bytes 
of $88's or $00's there) or does it take the IV as the MSB and then 
take the value pointed to by the value on the data bus (in my case 
it's be $9288 or $9200).  I haven't tried the second case yet, but I 
figured that someone on the list should know.


Thanks


-Ed
Follow-Ups: