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Any programs to easily set the CACR registers on the 030 CPU ?
Posted: 23 Mar 2026 16:01
by exxos
Not sure such a thing exists ?
Mostly want to be able to change any bit in the register...
Really needs to be a ACC as well :roll:
EDIT:
I will try and get AI to write me one..
Re: Any programs to easily set the CACR registers on the 030 CPU ?
Posted: 23 Mar 2026 21:41
by alexh
There should be lots for TT030 and Falcon030 (plus CT6x).
https://atari.8bitchip.info/GamexUsage.html
https://atari.8bitchip.info/GamexLSrc2.html
(Look for cacr in the source)
http://leonard.oxg.free.fr/articles/mul ... atari.html
Code: Select all
moveq #0,d0 ; replace #0 with whatever you want
dc.l $4e7b0002 ; this is <movec d0,cacr> encoded for assemblers without movec
Re: Any programs to easily set the CACR registers on the 030 CPU ?
Posted: 23 Mar 2026 22:03
by exxos
AI wrote me some code to do it , but not tested it yet :)
Code: Select all
; NOIBURST.S - Disable 68030 instruction burst
; Assemble with Devpac 3: opt p=68030
; Run from desktop, then run ROM benchmark
opt p=68030
pea super_off(pc)
move.w #38,-(sp) ; Supexec
trap #14 ; XBIOS
addq.l #6,sp
pea msg_off(pc)
move.w #9,-(sp) ; Cconws
trap #1 ; GEMDOS
addq.l #6,sp
move.w #1,-(sp) ; Cconin - wait for key
trap #1
addq.l #2,sp
clr.w -(sp) ; Pterm0
trap #1
super_off:
movec cacr,d0
bclr #12,d0 ; clear instruction burst enable
movec d0,cacr
rts
msg_off:
dc.b "Instruction burst DISABLED",13,10
dc.b "Press any key...",13,10,0
even