Login
Search for:


Previous | Next

From: Rachy (all posts)
Date: 2001-07-26
Subject: Re: Castle Master once again
Hello once again!

On 26 Jul 2001, at 10:32, Marko Mäkelä wrote:

> The snippet you posted didn't specify how the IRQ sources have been
> initialized. Even if interrupts are enabled on the processor, the
> interrupt sources (timer, raster line comparison, etc.) can be
> disabled on the TED. Could it be like this?

I don't exactly know how the interrupt set up in this program,
because it left as the intro did. I assume there is a timer IRQ set up, due to the digital sound, with a short interval. It was definitely not disabled in any way, because then the program actually would work on every emulator then.

> If the IRQ line is asserted while the Interrupt flag is set in the
> processor's status register and if it restores to inactive state
> before the Interrupt flag is cleared (probably by writing to a TED
> register; I don't remember the C16 so well), the processor won't
> execute the interrupt sequence.

That is right, by writing to $FF09 all IRQ cleared. But the IRQs were active, that is why Castle Master crashed on emulators. In some way completion of request delayed on the real hardware.
I am trying to write some kind of test code later, to explain what is the trouble, as long as I can get a real Plus/4. (A simulation of this situation.)

Thanks anyway!

Bye:

Almos Rajnai

+------------------------=%%&############&%%=-------------------------------+
| Rachy of Bi0Hazard | PowerAmiga owner | http://amigos.amiga.hu/rachy/ |
|e-mail: racs@fs2.bdtf.hu| No Risc No Fun! | ATO Hungarian member |
+---ICQ:-16342960--------=%%&############&%%=-----Phone:+36 20 9891489------+

Copyright © Plus/4 World Team, 2001-2024