Marc S. Ressl

Hello everyone,

This code was posted by emphasis at comp.sys.apple2.programmer:

10 A = 9200
20 B = 13136 + 32
30 C = 100
40 TEXT : HOME
50 DATA 173,87,192,173,83,192,173,84,192,173,80,192,208,25 1
55 DATA 173,86,192,160,22,136,208,253,234,173,87,192,76,9, 3
60 FOR I = 768 TO 796
70 READ N: POKE I,N
80 NEXT
100 HGR : POKE - 16302,0
110 HCOLOR= 4
120 HPLOT 0,0: CALL 62454
130 HCOLOR= 2
140 HPLOT 0,63 TO 279,63
150 HPLOT 0,62 TO 279,62
160 HCOLOR= 6
170 HPLOT 0,61 TO 279,61
180 HPLOT 0,60 TO 279,60
190 HCOLOR= 1
200 HPLOT 0,59 TO 279,59
210 HPLOT 0,58 TO 279,58
220 HCOLOR= 5
230 HPLOT 0,55 TO 279,55
240 HPLOT 0,54 TO 279,54
250 HCOLOR= 0
260 HPLOT 0,123 TO C,123
261 HPLOT 0,122 TO C,122
262 HPLOT 0,119 TO C,119
263 HPLOT 0,118 TO C,118
270 COLOR= 0
280 FOR I = 0 TO 39
290 VLIN 0,39 AT I
300 NEXT
310 COLOR= 13
320 HLIN 0,39 AT 14
330 FOR I = 0 TO 7
340 POKE A + I,0
345 POKE B + I,0
350 NEXT
360 COLOR= 1
370 HLIN 0,39 AT 13
380 VTAB 21
390 PRINT TAB( 16)"RAINBOW"
400 PRINT : PRINT "MIXED GRAPHICS (HI-RES/COLOR)"
500 CALL 768

I've re-factorized the timing code in OpenEmulator, and the rainbow is
showing. My problem is the "special" lines are flickering at the
beginning.

I have checked the code, and it seems it should be flickering (the
loop waits for a non-zero byte on the floating bus), but could
somebody with a real Apple II or II plus check?

Thanks a lot,

Marc.-

mmphosis

On Feb 5, 7:25*pm, "Marc S. Ressl" <mre...@gmail.com> wrote:
> Hello everyone,
>
> This code was posted by mmphosis at comp.sys.apple2.programmer:
>
> *10 A = 9200
> *20 B = 13136 + 32
> *30 C = 100
> *40 *TEXT : HOME
> *50 DATA 173,87,192,173,83,192,173,84,192,173,80,192,208,25 1
> *55 DATA 173,86,192,160,22,136,208,253,234,173,87,192,76,9, 3
> *60 *FOR I = 768 TO 796
> *70 *READ N: POKE I,N
> *80 *NEXT
> *100 *HGR : POKE *- 16302,0
> *110 *HCOLOR= 4
> *120 *HPLOT 0,0: CALL 62454
> *130 *HCOLOR= 2
> *140 *HPLOT 0,63 TO 279,63
> *150 *HPLOT 0,62 TO 279,62
> *160 *HCOLOR= 6
> *170 *HPLOT 0,61 TO 279,61
> *180 *HPLOT 0,60 TO 279,60
> *190 *HCOLOR= 1
> *200 *HPLOT 0,59 TO 279,59
> *210 *HPLOT 0,58 TO 279,58
> *220 *HCOLOR= 5
> *230 *HPLOT 0,55 TO 279,55
> *240 *HPLOT 0,54 TO 279,54
> *250 *HCOLOR= 0
> *260 *HPLOT 0,123 TO C,123
> *261 *HPLOT 0,122 TO C,122
> *262 *HPLOT 0,119 TO C,119
> *263 *HPLOT 0,118 TO C,118
> *270 *COLOR= 0
> *280 *FOR I = 0 TO 39
> *290 *VLIN 0,39 AT I
> *300 *NEXT
> *310 *COLOR= 13
> *320 *HLIN 0,39 AT 14
> *330 *FOR I = 0 TO 7
> *340 *POKE A + I,0
> *345 *POKE B + I,0
> *350 *NEXT
> *360 *COLOR= 1
> *370 *HLIN 0,39 AT 13
> *380 *VTAB 21
> *390 *PRINT *TAB( 16)"RAINBOW"
> *400 *PRINT : PRINT "MIXED GRAPHICS (HI-RES/COLOR)"
> *500 *CALL 768
>
> I've re-factorized the timing code in OpenEmulator, and the rainbow is
> showing. My problem is the "special" lines are flickering at the
> beginning.
>
> I have checked the code, and it seems it should be flickering (the
> loop waits for a non-zero byte on the floating bus), but could
> somebody with a real Apple II or II plus check?
>
> Thanks a lot,
>
> Marc.-

From memory, a long long time ago, when I ran this on a real Apple II
plus, it would *usually* (emphasis on usually) display the rainbow
without any flickering. But, I think that sometimes, if my memory
serves me, it would flicker. It could be a timing thing: The code
waits for a non-zero byte on the floating bus and it can only catch a
byte every amount of cycles that the loop takes to iterate. The
positioning of those zero bytes is critical. Maybe, sometimes it
misses depending on what byte it starts reading the floating bus at,
whereas *usually* (mmphosis on usually) it starts reading at a byte
where everything aligns and the rainbow appears without flickering.

mmphosis

Marc S. Ressl

On 6 feb, 20:57, mmphosis <mmpho...@yahoo.com> wrote:
> On Feb 5, 7:25*pm, "Marc S. Ressl" <mre...@gmail.com> wrote:
>
>
>
>
>
>
>
>
>
> > Hello everyone,
>
> > This code was posted by mmphosis at comp.sys.apple2.programmer:
>
> > *10 A = 9200
> > *20 B = 13136 + 32
> > *30 C = 100
> > *40 *TEXT : HOME
> > *50 DATA 173,87,192,173,83,192,173,84,192,173,80,192,208,25 1
> > *55 DATA 173,86,192,160,22,136,208,253,234,173,87,192,76,9, 3
> > *60 *FOR I = 768 TO 796
> > *70 *READ N: POKE I,N
> > *80 *NEXT
> > *100 *HGR : POKE *- 16302,0
> > *110 *HCOLOR= 4
> > *120 *HPLOT 0,0: CALL 62454
> > *130 *HCOLOR= 2
> > *140 *HPLOT 0,63 TO 279,63
> > *150 *HPLOT 0,62 TO 279,62
> > *160 *HCOLOR= 6
> > *170 *HPLOT 0,61 TO 279,61
> > *180 *HPLOT 0,60 TO 279,60
> > *190 *HCOLOR= 1
> > *200 *HPLOT 0,59 TO 279,59
> > *210 *HPLOT 0,58 TO 279,58
> > *220 *HCOLOR= 5
> > *230 *HPLOT 0,55 TO 279,55
> > *240 *HPLOT 0,54 TO 279,54
> > *250 *HCOLOR= 0
> > *260 *HPLOT 0,123 TO C,123
> > *261 *HPLOT 0,122 TO C,122
> > *262 *HPLOT 0,119 TO C,119
> > *263 *HPLOT 0,118 TO C,118
> > *270 *COLOR= 0
> > *280 *FOR I = 0 TO 39
> > *290 *VLIN 0,39 AT I
> > *300 *NEXT
> > *310 *COLOR= 13
> > *320 *HLIN 0,39 AT 14
> > *330 *FOR I = 0 TO 7
> > *340 *POKE A + I,0
> > *345 *POKE B + I,0
> > *350 *NEXT
> > *360 *COLOR= 1
> > *370 *HLIN 0,39 AT 13
> > *380 *VTAB 21
> > *390 *PRINT *TAB( 16)"RAINBOW"
> > *400 *PRINT : PRINT "MIXED GRAPHICS (HI-RES/COLOR)"
> > *500 *CALL 768
>
> > I've re-factorized the timing code in OpenEmulator, and the rainbow is
> > showing. My problem is the "special" lines are flickering at the
> > beginning.
>
> > I have checked the code, and it seems it should be flickering (the
> > loop waits for a non-zero byte on the floating bus), but could
> > somebody with a real Apple II or II plus check?
>
> > Thanks a lot,
>
> > Marc.-
>
> From memory, a long long time ago, when I ran this on a real Apple II
> plus, it would *usually* (emphasis on usually) display the rainbow
> without any flickering. *But, I think that sometimes, if my memory
> serves me, it would flicker. *It could be a timing thing: *The code
> waits for a non-zero byte on the floating bus and it can only catch a
> byte every amount of cycles that the loop takes to iterate. *The
> positioning of those zero bytes is critical. *Maybe, sometimes it
> misses depending on what byte it starts reading the floating bus at,
> whereas *usually* (mmphosis on usually) it starts reading at a byte
> where everything aligns and the rainbow appears without flickering.
>
> mmphosis

Hello mmphosis:

thanks a lot for your response! I am very intrigued by this test, as
it seems excellent for testing emulators. So I went through it...

As to the BASIC part:

* BASIC Lines 110-120 fill $2000-$3FFF with $80
* BASIC Lines 130-240 draw the HIRES color lines 54-55, 58-59, 60-61,
62-63
* BASIC Lines 250-263 fill lines 118, 119, 122 and 123 with color 0
for X = 0 to 100 (this hides the delayed extensions of lines 54-63)
* BASIC Lines 330-350 fill $23F0-$23F7 and $3370-$3377 with $00 (this
is the important stuff)

* BASIC Lines 270-300 clear the text screen to $00
* BASIC Lines 360-380 draw the LORES line at Y=13 (HIRES lines 52-55)
* BASIC Lines 310-320 draw the LORES line at Y=14 (HIRES lines 56-59)

As to the assembly part:

0300- AD 57 C0 LDA $C057 // set HIRES
0303- AD 53 C0 LDA $C053 // set MIXED
0306- AD 54 C0 LDA $C054 // clear PAGE2

0309- AD 50 C0 LDA $C050 // read /TEXT, 4 cycles
030C- D0 FB BNE $0309 // 3 cycles
030E- AD 56 C0 LDA $C056 // set LORES, 4 cycles
0311- A0 16 LDY #$16 // 2 cycles
0313- 88 DEY // 2 cycles
0314- D0 FD BNE $0313 // 3 cycles
0316- EA NOP // 2 cycles
0317- AD 57 C0 LDA $C057 // set HIRES, 4 cycles
031A- 4C 09 03 JMP $0309 // 3 cycles

The first loop searches for a zero value while scanning HIRES. This
happens on several occasions, but most importantly just before lines
51 and 55 (because of horizontal blanking).

When the first loop exits, LORES is switched on for 4+2+5*22+2 = 118
CPU cycles. This happens to be almost two scan lines (each scan line
has 65 CPU cycles).

I must confess this is pretty clever, and it also seems my emulator
has a bug :-).

With the best wishes,

Marc.-

Marc S. Ressl

On 8 feb, 00:32, "Marc S. Ressl" <mre...@gmail.com> wrote:
> On 6 feb, 20:57, mmphosis <mmpho...@yahoo.com> wrote:
>
>
>
>
>
>
>
>
>
> > On Feb 5, 7:25*pm, "Marc S. Ressl" <mre...@gmail.com> wrote:
>
> > > Hello everyone,
>
> > > This code was posted by mmphosis at comp.sys.apple2.programmer:
>
> > > *10 A = 9200
> > > *20 B = 13136 + 32
> > > *30 C = 100
> > > *40 *TEXT : HOME
> > > *50 DATA 173,87,192,173,83,192,173,84,192,173,80,192,208,25 1
> > > *55 DATA 173,86,192,160,22,136,208,253,234,173,87,192,76,9, 3
> > > *60 *FOR I = 768 TO 796
> > > *70 *READ N: POKE I,N
> > > *80 *NEXT
> > > *100 *HGR : POKE *- 16302,0
> > > *110 *HCOLOR= 4
> > > *120 *HPLOT 0,0: CALL 62454
> > > *130 *HCOLOR= 2
> > > *140 *HPLOT 0,63 TO 279,63
> > > *150 *HPLOT 0,62 TO 279,62
> > > *160 *HCOLOR= 6
> > > *170 *HPLOT 0,61 TO 279,61
> > > *180 *HPLOT 0,60 TO 279,60
> > > *190 *HCOLOR= 1
> > > *200 *HPLOT 0,59 TO 279,59
> > > *210 *HPLOT 0,58 TO 279,58
> > > *220 *HCOLOR= 5
> > > *230 *HPLOT 0,55 TO 279,55
> > > *240 *HPLOT 0,54 TO 279,54
> > > *250 *HCOLOR= 0
> > > *260 *HPLOT 0,123 TO C,123
> > > *261 *HPLOT 0,122 TO C,122
> > > *262 *HPLOT 0,119 TO C,119
> > > *263 *HPLOT 0,118 TO C,118
> > > *270 *COLOR= 0
> > > *280 *FOR I = 0 TO 39
> > > *290 *VLIN 0,39 AT I
> > > *300 *NEXT
> > > *310 *COLOR= 13
> > > *320 *HLIN 0,39 AT 14
> > > *330 *FOR I = 0 TO 7
> > > *340 *POKE A + I,0
> > > *345 *POKE B + I,0
> > > *350 *NEXT
> > > *360 *COLOR= 1
> > > *370 *HLIN 0,39 AT 13
> > > *380 *VTAB 21
> > > *390 *PRINT *TAB( 16)"RAINBOW"
> > > *400 *PRINT : PRINT "MIXED GRAPHICS (HI-RES/COLOR)"
> > > *500 *CALL 768
>
> > > I've re-factorized the timing code in OpenEmulator, and the rainbow is
> > > showing. My problem is the "special" lines are flickering at the
> > > beginning.
>
> > > I have checked the code, and it seems it should be flickering (the
> > > loop waits for a non-zero byte on the floating bus), but could
> > > somebody with a real Apple II or II plus check?
>
> > > Thanks a lot,
>
> > > Marc.-
>
> > From memory, a long long time ago, when I ran this on a real Apple II
> > plus, it would *usually* (emphasis on usually) display the rainbow
> > without any flickering. *But, I think that sometimes, if my memory
> > serves me, it would flicker. *It could be a timing thing: *The code
> > waits for a non-zero byte on the floating bus and it can only catch a
> > byte every amount of cycles that the loop takes to iterate. *The
> > positioning of those zero bytes is critical. *Maybe, sometimes it
> > misses depending on what byte it starts reading the floating bus at,
> > whereas *usually* (mmphosis on usually) it starts reading at a byte
> > where everything aligns and the rainbow appears without flickering.
>
> > mmphosis
>
> Hello mmphosis:
>
> thanks a lot for your response! I am very intrigued by this test, as
> it seems excellent for testing emulators. So I went through it...
>
> As to the BASIC part:
>
> * BASIC Lines 110-120 fill $2000-$3FFF with $80
> * BASIC Lines 130-240 draw the HIRES color lines 54-55, 58-59, 60-61,
> 62-63
> * BASIC Lines 250-263 fill lines 118, 119, 122 and 123 with color 0
> for X = 0 to 100 (this hides the delayed extensions of lines 54-63)
> * BASIC Lines 330-350 fill $23F0-$23F7 and $3370-$3377 with $00 (this
> is the important stuff)
>
> * BASIC Lines 270-300 clear the text screen to $00
> * BASIC Lines 360-380 draw the LORES line at Y=13 (HIRES lines 52-55)
> * BASIC Lines 310-320 draw the LORES line at Y=14 (HIRES lines 56-59)
>
> As to the assembly part:
>
> 0300- * AD 57 C0 * *LDA * $C057 * * // set HIRES
> 0303- * AD 53 C0 * *LDA * $C053 * * // set MIXED
> 0306- * AD 54 C0 * *LDA * $C054 * * // clear PAGE2
>
> 0309- * AD 50 C0 * *LDA * $C050 * * // read /TEXT, 4 cycles
> 030C- * D0 FB * * * BNE * $0309 * * // 3 cycles
> 030E- * AD 56 C0 * *LDA * $C056 * * // set LORES, 4 cycles
> 0311- * A0 16 * * * LDY * #$16 * * *// 2 cycles
> 0313- * 88 * * * * *DEY * * * * * * // 2 cycles
> 0314- * D0 FD * * * BNE * $0313 * * // 3 cycles
> 0316- * EA * * * * *NOP * * * * * * // 2 cycles
> 0317- * AD 57 C0 * *LDA * $C057 * * // set HIRES, 4 cycles
> 031A- * 4C 09 03 * *JMP * $0309 * * // 3 cycles
>
> The first loop searches for a zero value while scanning HIRES. This
> happens on several occasions, but most importantly just before lines
> 51 and 55 (because of horizontal blanking).
>
> When the first loop exits, LORES is switched on for 4+2+5*22+2 = 118
> CPU cycles. This happens to be almost two scan lines (each scan line
> has 65 CPU cycles).
>
> I must confess this is pretty clever, and it also seems my emulator
> has a bug :-).
>
> With the best wishes,
>
> Marc.-

Hallelujah! I fixed it.

It happens the actual video rendering was 9 cycles behind the floating
bus timing. Now things match, and the test looks beautifully ;-).

With the best wishes!

Marc.-

Antoine Vignau

On 9 fév, 02:33, "Marc S. Ressl" <mre...@gmail.com> wrote:
> On 8 feb, 00:32, "Marc S. Ressl" <mre...@gmail.com> wrote:
>
>
>
>
>
>
>
>
>
> > On 6 feb, 20:57, mmphosis <mmpho...@yahoo.com> wrote:
>
> > > On Feb 5, 7:25*pm, "Marc S. Ressl" <mre...@gmail.com> wrote:
>
> > > > Hello everyone,
>
> > > > This code was posted by mmphosis at comp.sys.apple2.programmer:
>
> > > > *10 A = 9200
> > > > *20 B = 13136 + 32
> > > > *30 C = 100
> > > > *40 *TEXT : HOME
> > > > *50 DATA 173,87,192,173,83,192,173,84,192,173,80,192,208,25 1
> > > > *55 DATA 173,86,192,160,22,136,208,253,234,173,87,192,76,9, 3
> > > > *60 *FOR I = 768 TO 796
> > > > *70 *READ N: POKE I,N
> > > > *80 *NEXT
> > > > *100 *HGR : POKE *- 16302,0
> > > > *110 *HCOLOR= 4
> > > > *120 *HPLOT 0,0: CALL 62454
> > > > *130 *HCOLOR= 2
> > > > *140 *HPLOT 0,63 TO 279,63
> > > > *150 *HPLOT 0,62 TO 279,62
> > > > *160 *HCOLOR= 6
> > > > *170 *HPLOT 0,61 TO 279,61
> > > > *180 *HPLOT 0,60 TO 279,60
> > > > *190 *HCOLOR= 1
> > > > *200 *HPLOT 0,59 TO 279,59
> > > > *210 *HPLOT 0,58 TO 279,58
> > > > *220 *HCOLOR= 5
> > > > *230 *HPLOT 0,55 TO 279,55
> > > > *240 *HPLOT 0,54 TO 279,54
> > > > *250 *HCOLOR= 0
> > > > *260 *HPLOT 0,123 TO C,123
> > > > *261 *HPLOT 0,122 TO C,122
> > > > *262 *HPLOT 0,119 TO C,119
> > > > *263 *HPLOT 0,118 TO C,118
> > > > *270 *COLOR= 0
> > > > *280 *FOR I = 0 TO 39
> > > > *290 *VLIN 0,39 AT I
> > > > *300 *NEXT
> > > > *310 *COLOR= 13
> > > > *320 *HLIN 0,39 AT 14
> > > > *330 *FOR I = 0 TO 7
> > > > *340 *POKE A + I,0
> > > > *345 *POKE B + I,0
> > > > *350 *NEXT
> > > > *360 *COLOR= 1
> > > > *370 *HLIN 0,39 AT 13
> > > > *380 *VTAB 21
> > > > *390 *PRINT *TAB( 16)"RAINBOW"
> > > > *400 *PRINT : PRINT "MIXED GRAPHICS (HI-RES/COLOR)"
> > > > *500 *CALL 768
>
> > > > I've re-factorized the timing code in OpenEmulator, and the rainbowis
> > > > showing. My problem is the "special" lines are flickering at the
> > > > beginning.
>
> > > > I have checked the code, and it seems it should be flickering (the
> > > > loop waits for a non-zero byte on the floating bus), but could
> > > > somebody with a real Apple II or II plus check?
>
> > > > Thanks a lot,
>
> > > > Marc.-
>
> > > From memory, a long long time ago, when I ran this on a real Apple II
> > > plus, it would *usually* (emphasis on usually) display the rainbow
> > > without any flickering. *But, I think that sometimes, if my memory
> > > serves me, it would flicker. *It could be a timing thing: *The code
> > > waits for a non-zero byte on the floating bus and it can only catch a
> > > byte every amount of cycles that the loop takes to iterate. *The
> > > positioning of those zero bytes is critical. *Maybe, sometimes it
> > > misses depending on what byte it starts reading the floating bus at,
> > > whereas *usually* (mmphosis on usually) it starts reading at a byte
> > > where everything aligns and the rainbow appears without flickering.
>
> > > mmphosis
>
> > Hello mmphosis:
>
> > thanks a lot for your response! I am very intrigued by this test, as
> > it seems excellent for testing emulators. So I went through it...
>
> > As to the BASIC part:
>
> > * BASIC Lines 110-120 fill $2000-$3FFF with $80
> > * BASIC Lines 130-240 draw the HIRES color lines 54-55, 58-59, 60-61,
> > 62-63
> > * BASIC Lines 250-263 fill lines 118, 119, 122 and 123 with color 0
> > for X = 0 to 100 (this hides the delayed extensions of lines 54-63)
> > * BASIC Lines 330-350 fill $23F0-$23F7 and $3370-$3377 with $00 (this
> > is the important stuff)
>
> > * BASIC Lines 270-300 clear the text screen to $00
> > * BASIC Lines 360-380 draw the LORES line at Y=13 (HIRES lines 52-55)
> > * BASIC Lines 310-320 draw the LORES line at Y=14 (HIRES lines 56-59)
>
> > As to the assembly part:
>
> > 0300- * AD 57 C0 * *LDA * $C057 * * // set HIRES
> > 0303- * AD 53 C0 * *LDA * $C053 * * // set MIXED
> > 0306- * AD 54 C0 * *LDA * $C054 * * // clear PAGE2
>
> > 0309- * AD 50 C0 * *LDA * $C050 * * // read /TEXT, 4 cycles
> > 030C- * D0 FB * * * BNE * $0309 * * // 3 cycles
> > 030E- * AD 56 C0 * *LDA * $C056 * * // set LORES, 4 cycles
> > 0311- * A0 16 * * * LDY * #$16 * * *// 2 cycles
> > 0313- * 88 * * * * *DEY * * * * * * // 2 cycles
> > 0314- * D0 FD * * * BNE * $0313 * * // 3 cycles
> > 0316- * EA * * * * *NOP * * * * * * // 2 cycles
> > 0317- * AD 57 C0 * *LDA * $C057 * * // set HIRES, 4 cycles
> > 031A- * 4C 09 03 * *JMP * $0309 * * // 3 cycles
>
> > The first loop searches for a zero value while scanning HIRES. This
> > happens on several occasions, but most importantly just before lines
> > 51 and 55 (because of horizontal blanking).
>
> > When the first loop exits, LORES is switched on for 4+2+5*22+2 = 118
> > CPU cycles. This happens to be almost two scan lines (each scan line
> > has 65 CPU cycles).
>
> > I must confess this is pretty clever, and it also seems my emulator
> > has a bug :-).
>
> > With the best wishes,
>
> > Marc.-
>
> Hallelujah! I fixed it.
>
> It happens the actual video rendering was 9 cycles behind the floating
> bus timing. Now things match, and the test looks beautifully ;-).
>
> With the best wishes!
>
> Marc.-

Congratulions, Marc,
A really good news,
antoine

Marc S. Ressl

On 8 feb, 23:39, Antoine Vignau <antoine.vig...@laposte.net> wrote:
> Congratulions, Marc,
> A really good news,
> antoine

For your viewing pleasure:

http://openemulator.googlecode.com/files/rainbow2.png

;-D

With the best wishes,

Marc.-

BLuRry

Awesome! Glad to know this is possible! :-D Thanks Marc!

D Finnigan

Marc S. Ressl wrote:
> On 8 feb, 23:39, Antoine Vignau <antoine.vig...@laposte.net> wrote:
>> Congratulions, Marc,
>> A really good news,
>> antoine
>
> For your viewing pleasure:
>
> http://openemulator.googlecode.com/files/rainbow2.png
>
> ;-D
>

Perfect. That matches my photo that I took last evening:

http://macgui.com/gallery/showphoto.php?pic_id=1539

--
]DF$
Mac GUI Vault - A source for retro Apple II and
Macintosh computing.
http://macgui.com/vault/

Marc S. Ressl

On Feb 9, 1:58*pm, dog_...@macgui.com (D Finnigan) wrote:
> Marc S. Ressl wrote:
> > On 8 feb, 23:39, Antoine Vignau <antoine.vig...@laposte.net> wrote:
> >> Congratulions, Marc,
> >> A really good news,
> >> antoine
>
> > For your viewing pleasure:
>
> >http://openemulator.googlecode.com/files/rainbow2.png
>
> > ;-D
>
> Perfect. That matches my photo that I took last evening:
>
> http://macgui.com/gallery/showphoto.php?pic_id=1539
>
> --
> ]DF$
> Mac GUI Vault - A source for retro Apple II and
> Macintosh computing.http://macgui.com/vault/

Thanks a lot for posting that photo.

Now something else caught my attention. It seems the text colors do
not match. It should be cyan and orange, not green and violet.
Argh :-).

With the best wishes,

Marc.-

Antoine Vignau

On 9 fév, 03:39, Antoine Vignau <antoine.vig...@laposte.net> wrote:
> On 9 fév, 02:33, "Marc S. Ressl" <mre...@gmail.com> wrote:
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> > On 8 feb, 00:32, "Marc S. Ressl" <mre...@gmail.com> wrote:
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> > > On 6 feb, 20:57, mmphosis <mmpho...@yahoo.com> wrote:
>
> > > > On Feb 5, 7:25*pm, "Marc S. Ressl" <mre...@gmail.com> wrote:
>
> > > > > Hello everyone,
>
> > > > > This code was posted by mmphosis at comp.sys.apple2.programmer:
>
> > > > > *10 A = 9200
> > > > > *20 B = 13136 + 32
> > > > > *30 C = 100
> > > > > *40 *TEXT : HOME
> > > > > *50 DATA 173,87,192,173,83,192,173,84,192,173,80,192,208,25 1
> > > > > *55 DATA 173,86,192,160,22,136,208,253,234,173,87,192,76,9, 3
> > > > > *60 *FOR I = 768 TO 796
> > > > > *70 *READ N: POKE I,N
> > > > > *80 *NEXT
> > > > > *100 *HGR : POKE *- 16302,0
> > > > > *110 *HCOLOR= 4
> > > > > *120 *HPLOT 0,0: CALL 62454
> > > > > *130 *HCOLOR= 2
> > > > > *140 *HPLOT 0,63 TO 279,63
> > > > > *150 *HPLOT 0,62 TO 279,62
> > > > > *160 *HCOLOR= 6
> > > > > *170 *HPLOT 0,61 TO 279,61
> > > > > *180 *HPLOT 0,60 TO 279,60
> > > > > *190 *HCOLOR= 1
> > > > > *200 *HPLOT 0,59 TO 279,59
> > > > > *210 *HPLOT 0,58 TO 279,58
> > > > > *220 *HCOLOR= 5
> > > > > *230 *HPLOT 0,55 TO 279,55
> > > > > *240 *HPLOT 0,54 TO 279,54
> > > > > *250 *HCOLOR= 0
> > > > > *260 *HPLOT 0,123 TO C,123
> > > > > *261 *HPLOT 0,122 TO C,122
> > > > > *262 *HPLOT 0,119 TO C,119
> > > > > *263 *HPLOT 0,118 TO C,118
> > > > > *270 *COLOR= 0
> > > > > *280 *FOR I = 0 TO 39
> > > > > *290 *VLIN 0,39 AT I
> > > > > *300 *NEXT
> > > > > *310 *COLOR= 13
> > > > > *320 *HLIN 0,39 AT 14
> > > > > *330 *FOR I = 0 TO 7
> > > > > *340 *POKE A + I,0
> > > > > *345 *POKE B + I,0
> > > > > *350 *NEXT
> > > > > *360 *COLOR= 1
> > > > > *370 *HLIN 0,39 AT 13
> > > > > *380 *VTAB 21
> > > > > *390 *PRINT *TAB( 16)"RAINBOW"
> > > > > *400 *PRINT : PRINT "MIXED GRAPHICS (HI-RES/COLOR)"
> > > > > *500 *CALL 768
>
> > > > > I've re-factorized the timing code in OpenEmulator, and the rainbow is
> > > > > showing. My problem is the "special" lines are flickering at the
> > > > > beginning.
>
> > > > > I have checked the code, and it seems it should be flickering (the
> > > > > loop waits for a non-zero byte on the floating bus), but could
> > > > > somebody with a real Apple II or II plus check?
>
> > > > > Thanks a lot,
>
> > > > > Marc.-
>
> > > > From memory, a long long time ago, when I ran this on a real Apple II
> > > > plus, it would *usually* (emphasis on usually) display the rainbow
> > > > without any flickering. *But, I think that sometimes, if my memory
> > > > serves me, it would flicker. *It could be a timing thing: *The code
> > > > waits for a non-zero byte on the floating bus and it can only catcha
> > > > byte every amount of cycles that the loop takes to iterate. *The
> > > > positioning of those zero bytes is critical. *Maybe, sometimes it
> > > > misses depending on what byte it starts reading the floating bus at,
> > > > whereas *usually* (mmphosis on usually) it starts reading at a byte
> > > > where everything aligns and the rainbow appears without flickering.
>
> > > > mmphosis
>
> > > Hello mmphosis:
>
> > > thanks a lot for your response! I am very intrigued by this test, as
> > > it seems excellent for testing emulators. So I went through it...
>
> > > As to the BASIC part:
>
> > > * BASIC Lines 110-120 fill $2000-$3FFF with $80
> > > * BASIC Lines 130-240 draw the HIRES color lines 54-55, 58-59, 60-61,
> > > 62-63
> > > * BASIC Lines 250-263 fill lines 118, 119, 122 and 123 with color 0
> > > for X = 0 to 100 (this hides the delayed extensions of lines 54-63)
> > > * BASIC Lines 330-350 fill $23F0-$23F7 and $3370-$3377 with $00 (this
> > > is the important stuff)
>
> > > * BASIC Lines 270-300 clear the text screen to $00
> > > * BASIC Lines 360-380 draw the LORES line at Y=13 (HIRES lines 52-55)
> > > * BASIC Lines 310-320 draw the LORES line at Y=14 (HIRES lines 56-59)
>
> > > As to the assembly part:
>
> > > 0300- * AD 57 C0 * *LDA * $C057 * * // set HIRES
> > > 0303- * AD 53 C0 * *LDA * $C053 * * // set MIXED
> > > 0306- * AD 54 C0 * *LDA * $C054 * * // clear PAGE2
>
> > > 0309- * AD 50 C0 * *LDA * $C050 * * // read /TEXT, 4 cycles
> > > 030C- * D0 FB * * * BNE * $0309 * * // 3 cycles
> > > 030E- * AD 56 C0 * *LDA * $C056 * * // set LORES, 4 cycles
> > > 0311- * A0 16 * * * LDY * #$16 * * *// 2 cycles
> > > 0313- * 88 * * * * *DEY * * * * * * // 2 cycles
> > > 0314- * D0 FD * * * BNE * $0313 * * // 3 cycles
> > > 0316- * EA * * * * *NOP * * * * * * // 2 cycles
> > > 0317- * AD 57 C0 * *LDA * $C057 * * // set HIRES, 4 cycles
> > > 031A- * 4C 09 03 * *JMP * $0309 * * // 3 cycles
>
> > > The first loop searches for a zero value while scanning HIRES. This
> > > happens on several occasions, but most importantly just before lines
> > > 51 and 55 (because of horizontal blanking).
>
> > > When the first loop exits, LORES is switched on for 4+2+5*22+2 = 118
> > > CPU cycles. This happens to be almost two scan lines (each scan line
> > > has 65 CPU cycles).
>
> > > I must confess this is pretty clever, and it also seems my emulator
> > > has a bug :-).
>
> > > With the best wishes,
>
> > > Marc.-
>
> > Hallelujah! I fixed it.
>
> > It happens the actual video rendering was 9 cycles behind the floating
> > bus timing. Now things match, and the test looks beautifully ;-).
>
> > With the best wishes!
>
> > Marc.-
>
> Congratulions, Marc,
> A really good news,
> antoine

I hate the virtual keyboard of the ipad!
and I like the photos of yours, Gentlemen,
antoine