Previous Thread
Next Thread
Print Thread
Page 4 of 4 1 2 3 4
#112971 - 03/28/18 12:57 AM Re: Fairlight CMI [Re: SynaMax]  
Joined: Mar 2001
Posts: 15,896
R. Belmont Offline
R. Belmont  Offline

Very Senior Member

Joined: Mar 2001
Posts: 15,896
USA
You sure it's not switching CPUs at that point?

#112973 - 03/28/18 01:37 AM Re: Fairlight CMI [Re: SynaMax]  
Joined: Nov 2017
Posts: 18
SynaMax Offline
Member
SynaMax  Offline
Member

Joined: Nov 2017
Posts: 18
I just double checked and made sure I wasn't focused on CPU 1. When I hit either F10 or F11 to go to the next instruction, it stays on CPU1.

The only reference to 4FE2 I can find is here:

Code
8DB1: LDX   #$4FE2
8DB4: STX   $FFDE


EDIT: It's triggering an interrupt, I think. According to this site, FFDE-FFDF is IRQ15 (low priority PICU). $5025 is an RTI opcode and jumps back to $4FE2.

Last edited by SynaMax; 03/28/18 01:53 AM.
#112977 - 03/28/18 12:48 PM Re: Fairlight CMI [Re: SynaMax]  
Joined: Mar 2001
Posts: 15,896
R. Belmont Offline
R. Belmont  Offline

Very Senior Member

Joined: Mar 2001
Posts: 15,896
USA
Ahh, yeah, IRQ is the other reason the PC will go flying.

Page 4 of 4 1 2 3 4

Who's Online Now
5 registered members (Stick, Pernod, gerbilsrcute, Praxis, 1 invisible), 21 guests, and 3 spiders.
Key: Admin, Global Mod, Mod
Shout Box
Forum Statistics
Forums9
Topics8,525
Posts111,250
Members4,792
Most Online225
May 26th, 2014
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.024s Queries: 16 (0.008s) Memory: 4.9497 MB (Peak: 5.1483 MB) Zlib enabled. Server Time: 2018-04-20 18:21:33 UTC