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Stryyker
Registered: Dec 2001
Posts: 465 |
Richard's Interrupts
I thought this would be a better place to discuss your problem :)
Following the program makes no sense to me.
To end interrupts, you can JMP to a number of Kernal addresses, keyboard/withough keybaord scanning etc.
An alternative is RTI (ReTurn from Interrupt). This needs a little work if you use interrupt via $0314/$0315. You will need to PLA, TAX, PLA, TAY, PLA, RTI (maybe swap TAX with TAY as my memory fails me).
Most of the JMP $EA81 will not work as you branch before it is executed. You can do some embedding of interrupts within the current one but you will lose the purpose of what you want (double raster interrupt for stable rasters is a simple example).
I don't fully understand what you are trying to achieve and how but maybe somethink like:
INT1
lda #$00
sta $d020
sta $d021
lda #$7c
ldx #<INT2
ldy #>INT2
jmp FINint
INT2
lda #$06
sta $D020
sta $D021
jsr $1003
lda #$30
ldx #<INT1
ldy #>INT1
jmp FINint
FINint
sta $D012
stx $0314
sty $0315
lda #$01
sta $D019
jmp $EA81
It's only a guess but your bit in the question was a bit messy :) |
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T.M.R
Account closed
Registered: Dec 2001
Posts: 749 |
Quote: Why to keep the KERNAL enabled at all? If you take the kernal off the you can put the interrupt address straight the $fffe and $ffff
No hassling needed, only remember to store all the index registers beforehand (no need to use stack, simple sta/stx/sty is enough).
The main reason the KERNEL is enabled is because the interrupt comes from a *beginners* course in coding - i don't know about anyone else, but i think banking everything out is a little too advanced for that...? =-)
(That said, i personally leave the KERNEL banked in on my stuff, but i'm lazy. =-) |
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Stryyker
Registered: Dec 2001
Posts: 465 |
lda #$35
sta $01
switches out the BASIC and kernal ROMs but keeping the IO area switched in. Some precautions are needed or else you'll crash :) |
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T.M.R
Account closed
Registered: Dec 2001
Posts: 749 |
Quote: lda #$35
sta $01
switches out the BASIC and kernal ROMs but keeping the IO area switched in. Some precautions are needed or else you'll crash :)
Erm, where are the *interupts* then...? =-) |
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Stryyker
Registered: Dec 2001
Posts: 465 |
Someone earlier pointed out the interrupt (IRQ) addresses when the kernal is switched out. Richard asked for alisting to swtich out the ROM, so I did :) |
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T.M.R
Account closed
Registered: Dec 2001
Posts: 749 |
Quote: Someone earlier pointed out the interrupt (IRQ) addresses when the kernal is switched out. Richard asked for alisting to swtich out the ROM, so I did :)
Well, it's a little more complex than that, as we both (but Richard probably doesn't) know. Tell you what, you okay with Richard sending you his source when he tries to do it and it doesn't work...?
(He sent it to me already, it must be someone else's go surely? =-) |
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chatGPZ
Registered: Dec 2001
Posts: 11100 |
raster interupt w/o kernal.... from the top of my head (someone else fix the bugs ;=P)
sei
lda #$35
sta $01
lda #>irq
sta $ffff
lda #<irq
sta $fffe
lda #$01
sta $d01a
lda #$7f
sta $dc0d
lda #$30
sta $d012
lda #$1b
sta $d011
lda $dc0d
ror $d019
cli
jmp *
irq:
stx sx+1
sty sy+1
sta sa+1
; do stuff
sx: ldx #$00
sy: ldy #$00
sa: lda #$00
ror $d019
rti |
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Stryyker
Registered: Dec 2001
Posts: 465 |
I use lda #$01, sta $d019 but I work to make most of my stuff to work with SCPU. I think it changes the 2 writes for the read-modify-write commands. |
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Dosoo
Account closed
Registered: Apr 2002
Posts: 32 |
It just came to my mind, that a listing of a working raster interrupt with the kernal disabled was published with my Amebas graphic editor. The display.source works with raster interrupt. The code should be standard Turbo Assembler code. |
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Richard
Registered: Dec 2001
Posts: 619 |
T.M.R: Thanks, the routines helped me a lot, and I have learned these routines and I am able to use these without a problem :)
Muchly appreciated |
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Richard
Registered: Dec 2001
Posts: 619 |
.... I've just learned today how to save raster time for scrolling. All I need to try now is double-buffering :)
Regarding TMR's example. I tried to do those splits in my own accord, but unfortunately the splits would not work. I only realised what the problem was - I missed the $D011 routine before assembling.
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