IIRC, RETI is used with Mode 2 interrupts to allow for interrupt daisy-chaining. Unless you've got hardware which uses them to vector interrupts to a table, you really don't want to use them.
I'm curious.. why are you using Mode 2 interrupts? It's slower than the regular ones, as it has to look up a vector table instead of just doing an RST &38. (Note: I'm incredibly rusty, so I might be completely off base here). -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of David Brant Sent: Thursday, October 30, 2008 10:55 AM To: [email protected] Subject: {Spam?} Re: interrupts ----- Original Message ----- From: "Simon Owen" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, October 30, 2008 5:31 PM Subject: Re: interrupts > David Brant wrote: >> I'm using mode 2 interrupts when I use sim coupe's debugger I get the >> normal frame interrupt and then a interrupt at line 0 point 52 (real >> line not SAM coupe line) anyone know whats producing it? > > It still sounds most likely to be a re-triggered interrupt, even if the > status port is &FF by the time you check it. Is your interrupt handler > fairly short? (close to the 128 cycles the interrupt is active for) > > If you can e-mail me a test disk image I'll be happy to take a look. > > Si > Yes its 76 cycles long, so that must be what's happening. While we are on the subject, is there any reason to use RETI over using just RET with interrupts.
