DLI Help

[+Stephen]

I'm going crazy here - please help!! I have setup a custom DLI which is doing what I want as far as setting the mode lines and screen RAM, etc. I have a DLI set in 3 places. My DLI code is fairly simple, just a quick register change or two. Before exiting the DLI, I load $0200 with the address of the code for the next DLI. I set all the relevant address on the machine $0200=$0000, $0201=$00B2 when I initially enable the DLIs. I am running test code via TurboBASIC and when I enable the DLIs, the machine doesn't crash, but the DLIs are not working correctly.

 

I'll post the DLIST and DLI code below.

> dlist
B100: 8 BLANK
B101: 8 BLANK
B102: DLI 7 BLANK
B103: LMS a000 MODE F
B106: MODE F
B107: MODE F
B108: MODE F
B109: MODE F
B10A: MODE F
B10B: MODE F
B10C: MODE F
B10D: MODE F
B10E: DLI MODE F
B10F: 8 BLANK
B110: MODE 6
B111: MODE 6
B112: MODE 6
B113: MODE 6
B114: MODE 6
B115: MODE 6
B116: MODE 6
B117: MODE 6
B118: MODE 6
B119: MODE 6
B11A: MODE 6
B11B: MODE 6
B11C: MODE 6
B11D: DLI MODE 6
B11E: MODE 6
B11F: MODE 6
B120: MODE 6
B121: MODE 6
B122: JVB b100
>
> d b200
B200    PHA                   ; 3cyc ; 48
B201    LDA #$81              ; 2cyc ; A9 81
B203    STA $D40A ;WSYNC      ; 4cyc ; 8D 0A D4
B206    STA $D01B ;PRIOR      ; 4cyc ; 8D 1B D0
B209    LDA #$3E              ; 2cyc ; A9 3E
B20B    STA $D400 ;DMACTL     ; 4cyc ; 8D 00 D4
B20E    LDA #$15              ; 2cyc ; A9 15
B210    STA $0200 ;VDSLST     ; 4cyc ; 8D 00 02
B213    PLA                   ; 4cyc ; 68
B214    RTI                   ; 6cyc ; 40
B215    PHA                   ; 3cyc ; 48
B216    LDA #$01              ; 2cyc ; A9 01
B218    STA $D40A ;WSYNC      ; 4cyc ; 8D 0A D4
B21B    STA $D01B ;PRIOR      ; 4cyc ; 8D 1B D0
B21E    LDA #$25              ; 2cyc ; A9 25
B220    STA $D400 ;DMACTL     ; 4cyc ; 8D 00 D4
B223    LDA #$2A              ; 2cyc ; A9 2A
B225    STA $0200 ;VDSLST     ; 4cyc ; 8D 00 02
B228    PLA                   ; 4cyc ; 68
B229    RTI                   ; 6cyc ; 40
B22A    PHA                   ; 3cyc ; 48
B22B    LDA #$3D              ; 2cyc ; A9 3D
B22D    STA $D40A ;WSYNC      ; 4cyc ; 8D 0A D4
B230    STA $D400 ;DMACTL     ; 4cyc ; 8D 00 D4
B233    LDA #$00              ; 2cyc ; A9 00
B235    STA $0200 ;VDSLST     ; 4cyc ; 8D 00 02
B238    PLA                   ; 4cyc ; 68
B239    RTI                   ; 6cyc ; 40

 

What I want is simple - 10 lines of ANTIC E, some blanks, then 18 lines of ANTIC 6. I want the 10 lines of ANTIC E to have GTIA 10 in standard playfield width, and the rest of the screen to be narrow playfield non GTIA.

 

When I run the above code, I get narrow playfield the entire screen, and where the 3rd DLI should execute, no characters are displayed on the screen at all. When I replaced my STA PRIORs with STA COLBKs, there was only one color change, and it was just above the final 4 MODE 6 lines.

 

This shows the working display list, with interrupts turned off

 

This is what happens when the above DLI code is enabled

 

This is what it looks like when I replace the 2 STA PRIORs with STA COLBKs

 

Thanks for any help.

 

Stephen Anderson

[dwhyte]

EDIT: My post wasn't relevant...

Edited September 18, 2009 by dwhyte

[Rybags]

You can't just set up multiple DLIs and be guaranteed they'll run in the order you hope them to.

 

Either do something reading VCOUNT to detect which DLI section should be run (which adds processing overhead you probably could do without), or have a VBlank routine that sets the vector to the first DLI.

 

Alternatively, you could leave DLIs disabled then call a piece of code similar to...

 

 lda 20  ; Low byte of RTCLOCK
wait
 cmp 20
 beq wait
 lda #$C0
 sta nmien  ; Enable all DLIs

 

Of course, make sure the DLI vector points to the first DLI. You then have to be real careful that you don't disable DLIs and re-enable them again without doing that procedure, and be careful not to alter the Display List in a way which could cause the sequence of DLIs to be disturbed.

[MaPa]

I don't know if you modify OS VBI etc. but if you didn't disabled shadow register copying in OS VBI, then you shoud do fine without the first DLI and have just two of them and set the values from first DLI as global setting. So these values will be there on top of the screen, then you change them two times to the lower part and in OS VBI it will be back to the starting values.

[+Stephen]

I don't know if you modify OS VBI etc. but if you didn't disabled shadow register copying in OS VBI, then you shoud do fine without the first DLI and have just two of them and set the values from first DLI as global setting. So these values will be there on top of the screen, then you change them two times to the lower part and in OS VBI it will be back to the starting values.

Thanks - I will give that a try this evening. Doing it that way, will I still need code to synchronize the lower 2 DLIs though?

 

Stephen Anderson

[Rybags]

Personally, I wouldn't do it that way.

 

Disable Stage 2 VBlank, you lose a whole lot of functionality, and you'll probably find later that you'd have to write extra code to bring it back.

 

I also notice your DLIs all do practically the same thing. You could just use a single DLI and put the values for PRIOR and DMACTL into a table.

[Synthpopalooza]

Here's a routine I found online which sets up 2 DLI's in a table. You can easily modify it to to DLI's on GPRIOR and DMACTL.

 

5 RESTORE 170:FOR N=0 TO 99:READ X:POKE 1664+N,X:NEXT N 
10 COLTAB=1712:LUMTAB=COLTAB+24 
14 X=USR(1693) 
40 POKE 512,128 
50 POKE 513,6 
60 DSTART=DPEEK(560) 
70 FOR N=DSTART+6 TO DSTART+28 
80 POKE N,130 
90 NEXT N 
100 POKE DSTART+3,194
120 POKE 54286,192 
130 END 
170 DATA 72,138,72,174,156,6,189,176,6,141 
180 DATA 10,212,141,9,212,189,200,6,141,27 
190 DATA 208,238,156,6,104,170,104,64,14,104 
200 DATA 169,7,160,168,162,6,32,92,228,96 
210 DATA 169,1,141,156,6,76,98,228,162,170 
220 DATA 156,170,156,170,156,170,156,170,156,170 
230 DATA 156,170,156,170,156,170,156,162,204,204 
240 DATA 204,204,14,64,64,64,64,64,64,64 
250 DATA 64,64,64,0,0,0,0,0,0,64 
260 DATA 64,64,64,64,64,64,64,0,64,64 

Edited September 18, 2009 by Synthpopalooza

[MaPa]

Personally, I wouldn't do it that way.

 

Disable Stage 2 VBlank, you lose a whole lot of functionality, and you'll probably find later that you'd have to write extra code to bring it back.

 

I also notice your DLIs all do practically the same thing. You could just use a single DLI and put the values for PRIOR and DMACTL into a table.

 

Maybe I understand it wrong but it seems to me that you think I suggested to disable stage 2 of VBI? The opposite is true, I suggested to use OS VBI shadow registry copying to get rid of one of the DLI.

[MaPa]

I don't know if you modify OS VBI etc. but if you didn't disabled shadow register copying in OS VBI, then you shoud do fine without the first DLI and have just two of them and set the values from first DLI as global setting. So these values will be there on top of the screen, then you change them two times to the lower part and in OS VBI it will be back to the starting values.

Thanks - I will give that a try this evening. Doing it that way, will I still need code to synchronize the lower 2 DLIs though?

 

Stephen Anderson

 

Yes, you will need to do the sync. But if only two DLI's are running you can just check VCOUNT and branch accordingly. Something like:

 

DLI  pha
    lda VCOUNT
    cmp #some_adequate_constant
    bcs DLI2
    ...  and here starts your first DLI
    ...
    pla
    rti

DLI2
    ...  and here your second DLI for bottom part
    ...
    pla
    rti

Edited September 18, 2009 by MaPa

[+Stephen]

I also notice your DLIs all do practically the same thing. You could just use a single DLI and put the values for PRIOR and DMACTL into a table.

Ahh - I never thought of that. Makes perfect sense, I think I'll do it this way. I'm having a much harder time going back to 6502 coding than I imagined I would. Too many years of object oriented C on machines with practically unlimited resources has clouded my thought process

 

It's my goal to have this custom screen setup & running this weekend, even if I have to pull a 24 hour marathon session to finish it! Sad considering this should be a 5 minute task.

 

Thanks for all the help guys. There really needs to be a code repository started for things such as this. I have most of the good Atari books (in hardcopy) and none really do a great job explaining multiple DLIs on a screen and these types of problems (synchronizing with display, etc.)

 

Stephen Anderson

[Heaven/TQA]

I also notice your DLIs all do practically the same thing. You could just use a single DLI and put the values for PRIOR and DMACTL into a table.

Ahh - I never thought of that. Makes perfect sense, I think I'll do it this way. I'm having a much harder time going back to 6502 coding than I imagined I would. Too many years of object oriented C on machines with practically unlimited resources has clouded my thought process

 

It's my goal to have this custom screen setup & running this weekend, even if I have to pull a 24 hour marathon session to finish it! Sad considering this should be a 5 minute task.

 

Thanks for all the help guys. There really needs to be a code repository started for things such as this. I have most of the good Atari books (in hardcopy) and none really do a great job explaining multiple DLIs on a screen and these types of problems (synchronizing with display, etc.)

 

Stephen Anderson

 

re: setting up the OS VBL

 

you can use the so called SETVBL routine (check atari archives for some books maybe in De Re) but of course you can do this, too:

 

lda #<vbl

sta 546

lda #>vbl

sta 547

...

 

vbl:

lda #<first_dli

sta 512

lda #>first_dli

sta 513

jmp $e45f

 

or you do

 

lda #<vbl

sta 548

lda #>vbl

sta 549

...

vbl:

lda #<first_dli

sta 512

lda #>first_dli

sta 513

jmp $e462 ;deferred vbl called "XITVBL"

 

should work on XL and XE models but not on 400/800.

[atariksi]

I also notice your DLIs all do practically the same thing. You could just use a single DLI and put the values for PRIOR and DMACTL into a table.

Ahh - I never thought of that. Makes perfect sense, I think I'll do it this way. I'm having a much harder time going back to 6502 coding than I imagined I would. Too many years of object oriented C on machines with practically unlimited resources has clouded my thought process

 

It's my goal to have this custom screen setup & running this weekend, even if I have to pull a 24 hour marathon session to finish it! Sad considering this should be a 5 minute task.

 

Thanks for all the help guys. There really needs to be a code repository started for things such as this. I have most of the good Atari books (in hardcopy) and none really do a great job explaining multiple DLIs on a screen and these types of problems (synchronizing with display, etc.)

 

Stephen Anderson

 

re: setting up the OS VBL

 

you can use the so called SETVBL routine (check atari archives for some books maybe in De Re) but of course you can do this, too:

 

lda #<vbl

sta 546

lda #>vbl

sta 547

...

 

vbl:

lda #<first_dli

sta 512

lda #>first_dli

sta 513

jmp $e45f

 

or you do

 

lda #<vbl

sta 548

lda #>vbl

sta 549

...

vbl:

lda #<first_dli

sta 512

lda #>first_dli

sta 513

jmp $e462 ;deferred vbl called "XITVBL"

 

should work on XL and XE models but not on 400/800.

 

That should work on 400/800 as well since you are using the vectors and not directly the addresses they point to or where you talking about something else?

[Heaven/TQA]

well... I was not sure if XITVBL ($e462 and $e45f) are the same on 400/800...

[atariksi]

well... I was not sure if XITVBL ($e462 and $e45f) are the same on 400/800...

 

I have been using vectors as given in Mapping the Atari (400/800) and they work fine on 800XL/130XE/etc. but I haven't tried the 58481 (BLKBDV) to see what that does on 800XL.

 

58448 E450 DISKIV

58451 E453 DSKINV

58454 E456 CIOV

58457 E459 SIOV

58460 E45C SETVBV

58463 E45F SYSVBV

58466 E462 XITVBV

58469 E465 SIOINV

58472 E468 SENDEV

58475 E46B INTINV

58478 E46E CIOINV

58481 E471 BLKBDV

58484 E474 WARMSV

58487 E477 COLDSV

[Rybags]

"Blackboard vector" exits to Self-Test on XL/XE.

[+Stephen]

Thanks Heaven - I used your suggestion of some VBI code to sync the uppermost DLI to the top of the screen. Worked a charm. I used immediate mode VBI as the manuals I read said I have 200 cycles, and the code I was using took less than 20.

 

I now have a nice stable screen.

 

Stephen Anderson

[atariksi]

"Blackboard vector" exits to Self-Test on XL/XE.

 

Just tried it out. The difference is that Atari 400/800 you can go back to BASIC with program in-tact by hitting RESET whereas to get out of SELF-TEST, you end up doing a cold boot when you hit RESET.