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Screen Scrolling

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  Screen Scrolling "duhas...@gmail.com" <duhast6377@gmail.com> - 2022-05-06 20:38 -0700
    Re: Screen Scrolling barrym95838 <barrym95838@yahoo.com> - 2022-05-07 01:46 -0700
      Re: Screen Scrolling qkumba <peter.ferrie@gmail.com> - 2022-05-07 12:39 -0700
        Re: Screen Scrolling barrym95838 <barrym95838@yahoo.com> - 2022-05-08 01:24 -0700
        Re: Screen Scrolling kegs@provalid.com (Kent Dickey) - 2022-05-09 04:03 +0000
          Re: Screen Scrolling qkumba <peter.ferrie@gmail.com> - 2022-05-09 09:41 -0700
            Re: Screen Scrolling Brian Patrie <bpatrie@bellsouth.spamisicky.net> - 2022-05-09 17:51 -0500
              Re: Screen Scrolling Brian Patrie <bpatrie@bellsouth.spamisicky.net> - 2022-05-13 02:15 -0500
          Re: Screen Scrolling qkumba <peter.ferrie@gmail.com> - 2022-05-09 09:42 -0700
          Re: Screen Scrolling Brian Patrie <bpatrie@bellsouth.spamisicky.net> - 2022-05-09 17:40 -0500
            Re: Screen Scrolling "duhas...@gmail.com" <duhast6377@gmail.com> - 2022-05-10 18:55 -0700
              Re: Screen Scrolling Jerry Penner <jerry+a2@jpen.ca> - 2022-05-10 21:57 -0600
                Re: Screen Scrolling Oliver Schmidt <ol.sc@web.de> - 2022-05-11 07:33 +0000
                Re: Screen Scrolling Brian Patrie <bpatrie@bellsouth.spamisicky.net> - 2022-05-13 02:33 -0500
    Re: Screen Scrolling I am Rob <gids.rs@sasktel.net> - 2022-05-07 14:22 -0700
    Re: Screen Scrolling Speccie <someone@somewhere.com> - 2022-05-08 07:55 +0100
    Re: Screen Scrolling mmphosis <mmphosis@macgui.com> - 2022-05-13 16:39 +0000

#47240 — Screen Scrolling

Or not scrolling I guess.  I want to fill a the text screen with a character,  in assembly.  I'm using COUT, but the last character will cause the screen to scroll up one line and leave a line blank at the bottom.  Is there a good way to prevent this beside printing everything but the last character and then directly sticking the last character into screen memory?

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#47241

On Friday, May 6, 2022 at 8:38:16 PM UTC-7, duhas...@gmail.com wrote:
> Or not scrolling I guess. I want to fill a the text screen with a character, in assembly.
> I'm using COUT, but the last character will cause the screen to scroll up one line and
> leave a line blank at the bottom. Is there a good way to prevent this beside printing
> everything but the last character and then directly sticking the last character into
> screen memory?
It might be a bit naughty, but have you tried poking a #$19 into ZP location $23?
Proceed at your own risk ... it's way past my bed time.

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#47242

HLINE and VLINE don't scroll.

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#47245

On Saturday, May 7, 2022 at 12:39:03 PM UTC-7, qkumba wrote:
> HLINE and VLINE don't scroll.
... and could be used to create a cool "wipe" effect @ 1 MHz.  Like!

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#47246

In article <f812d193-6a9e-4bfa-b896-8c6fdcef1f44n@googlegroups.com>,
qkumba  <peter.ferrie@gmail.com> wrote:
>HLINE and VLINE don't scroll.

To give a little more detail, try the following:

 10  FOR I = 0 TO 23
 20  COLOR= 3
 30  HLIN 0,39 AT I * 2
 40  COLOR= 10
 50  HLIN 0,39 AT I * 2 + 1
 60  NEXT
 70  FOR I = 1 TO 10000000
 80  NEXT

The HLIN (and VLIN and PLOT) commands work on the text screen, if you don't
give GR.

This writes "#" characters to the screen, and does not scroll.  For the 
character you want in hex, (0x23 for #), write each hex digit as decimal,
which is easy for this case: 2 and 3.  Put the low digit in the 20 COLOR=
line, and put the upper digit, plus 8 (to not be inverse or flashing) in
the 40 COLOR= line.

To fill the screen with "L", which is 0x5a, do 20 COLOR=10, 40 COLOR=13.

The FOR loop in lines 70,80 just show that the screen isn't scrolling.
Press ctrl-c to stop.

This doesn't work in 80 columns.

Kent

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#47247

> This doesn't work in 80 columns. 

Though it can:

33 POKE 49237,0
35 HLIN 0,39 AT I * 2
38 POKE 49236,0

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#47250

qkumba wrote:
>> This doesn't work in 80 columns.
> 
> Though it can:
> 
> 33 POKE 49237,0
> 35 HLIN 0,39 AT I * 2
> 38 POKE 49236,0

Sorta.  This mod will work on a IIe, or IIee, but will misbehave on a 
IIc, IIc+, or IIgs--which support DGR in firmware.  So you'd need to 
determine what you're running on, and act accordingly (or roll your own 
PLOT, HLINE, VLINE code).

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#47259

Brian Patrie wrote:
> qkumba wrote:
>>> This doesn't work in 80 columns.
>>
>> Though it can:
>>
>> 33 POKE 49237,0
>> 35 HLIN 0,39 AT I * 2
>> 38 POKE 49236,0
> 
> Sorta.  This mod will work on a IIe, or IIee, but will misbehave on a 
> IIc, IIc+, or IIgs--which support DGR in firmware.  So you'd need to 
> determine what you're running on, and act accordingly (or roll your own 
> PLOT, HLINE, VLINE code).

Erratum: This only seems to apply to AppleSoft--not the ml PLOT, VLINE, 
and HLINE calls.  (Tested with an emulated IIgs3.)

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#47248

> This doesn't work in 80 columns. 

Though it can:

33 POKE 49237,0
35 HLIN 0,39 AT I * 2
38 POKE 49236,0

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#47249

Kent Dickey wrote:
 > In article <f812d193-6a9e-4bfa-b896-8c6fdcef1f44n@googlegroups.com>,
 > qkumba  <peter.ferrie@gmail.com> wrote:
 >> HLINE and VLINE don't scroll.
 >
 > To give a little more detail, try the following:
 >
 >   10  FOR I = 0 TO 23
 >   20  COLOR= 3
 >   30  HLIN 0,39 AT I * 2
 >   40  COLOR= 10
 >   50  HLIN 0,39 AT I * 2 + 1
 >   60  NEXT
 >   70  FOR I = 1 TO 10000000
 >   80  NEXT
 >
 > The HLIN (and VLIN and PLOT) commands work on the text screen,
 > if you don't give GR.

Better yet, write directly to the colour mask byte:

   10  FOR I = 0 TO 47
   20  POKE 48,163
   30  HLIN 0,39 AT I
   40  NEXT
   90  ON PEEK(49152) < 128 GOTO 90 : POKE 49168,.

(That last line just waits for a key, and clears it.)

Or (on a machine with MouseText):

   10  PRINT CHR$(17); : POKE 49167,. : TEXT
   21  FOR X = 0 TO 38 STEP 2
   22  POKE 48,86 : VLIN 0,47 AT X
   23  POKE 48,87 : VLIN 0,47 AT X + 1
   24  NEXT
   90  ON PEEK(49152) < 128 GOTO 90 : POKE 49168,.

(Line 10 ensures 40 columns, alt charset, text mode.)

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#47252

On Monday, May 9, 2022 at 6:40:09 PM UTC-4, Brian Patrie wrote:
> Kent Dickey wrote: 
> > In article <f812d193-6a9e-4bfa...@googlegroups.com>, 
> > qkumba  wrote: 
> >> HLINE and VLINE don't scroll. 
> > 
> > To give a little more detail, try the following: 
> > 
> > 10 FOR I = 0 TO 23 
> > 20 COLOR= 3 
> > 30 HLIN 0,39 AT I * 2 
> > 40 COLOR= 10 
> > 50 HLIN 0,39 AT I * 2 + 1 
> > 60 NEXT 
> > 70 FOR I = 1 TO 10000000 
> > 80 NEXT 
> > 
> > The HLIN (and VLIN and PLOT) commands work on the text screen, 
> > if you don't give GR.
> Better yet, write directly to the colour mask byte: 
> 
> 10 FOR I = 0 TO 47 
> 20 POKE 48,163
> 30 HLIN 0,39 AT I
> 40 NEXT 
> 90 ON PEEK(49152) < 128 GOTO 90 : POKE 49168,. 
> 
> (That last line just waits for a key, and clears it.) 
> 
> Or (on a machine with MouseText): 
> 
> 10 PRINT CHR$(17); : POKE 49167,. : TEXT 
> 21 FOR X = 0 TO 38 STEP 2 
> 22 POKE 48,86 : VLIN 0,47 AT X 
> 23 POKE 48,87 : VLIN 0,47 AT X + 1 
> 24 NEXT 
> 90 ON PEEK(49152) < 128 GOTO 90 : POKE 49168,. 
> 
> (Line 10 ensures 40 columns, alt charset, text mode.)

Ok I tried the BASIC versions and they work like I want, but I tried to right a little assembly program to test it and I can't get it to work.

      
*300L                                   
0300-   A9 A3       LDA   #$A3       ;Load "#"   
0302-   85 30       STA   $30           ;Stick in color
0304-   A9 27       LDA   #$27         ;Load rightmost 
0306-   85 2C       STA   $2C           ;Stick in 2C
0308-   A9 09       LDA   #$09          ;Load vertical coord
030A-   A0 00       LDY   #$00          ;load horizontal coord
030C-   20 19 F8    JSR   $F819      ; call HLIN

Should have a line of # through the screen and I don;t....
 
0        
*                                       

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#47253

"duhas...@gmail.com" <duhast6377@gmail.com> writes:

> On Monday, May 9, 2022 at 6:40:09 PM UTC-4, Brian Patrie wrote:
>> Kent Dickey wrote: 
>> > In article <f812d193-6a9e-4bfa...@googlegroups.com>, 
>> > qkumba  wrote: 
>> >> HLINE and VLINE don't scroll. 
>> > 
>> > To give a little more detail, try the following: 
>> > 
>> > 10 FOR I = 0 TO 23 
>> > 20 COLOR= 3 
>> > 30 HLIN 0,39 AT I * 2 
>> > 40 COLOR= 10 
>> > 50 HLIN 0,39 AT I * 2 + 1 
>> > 60 NEXT 
>> > 70 FOR I = 1 TO 10000000 
>> > 80 NEXT 
>> > 
>> > The HLIN (and VLIN and PLOT) commands work on the text screen, 
>> > if you don't give GR.
>> Better yet, write directly to the colour mask byte: 
>> 
>> 10 FOR I = 0 TO 47 
>> 20 POKE 48,163
>> 30 HLIN 0,39 AT I
>> 40 NEXT 
>> 90 ON PEEK(49152) < 128 GOTO 90 : POKE 49168,. 
>> 
>> (That last line just waits for a key, and clears it.) 
>> 
>> Or (on a machine with MouseText): 
>> 
>> 10 PRINT CHR$(17); : POKE 49167,. : TEXT 
>> 21 FOR X = 0 TO 38 STEP 2 
>> 22 POKE 48,86 : VLIN 0,47 AT X 
>> 23 POKE 48,87 : VLIN 0,47 AT X + 1 
>> 24 NEXT 
>> 90 ON PEEK(49152) < 128 GOTO 90 : POKE 49168,. 
>> 
>> (Line 10 ensures 40 columns, alt charset, text mode.)
>
> Ok I tried the BASIC versions and they work like I want, but I tried to right a little
> assembly program to test it and I can't get it to work.
>
>       
> *300L                                   
> 0300-   A9 A3       LDA   #$A3       ;Load "#"   
> 0302-   85 30       STA   $30           ;Stick in color
> 0304-   A9 27       LDA   #$27         ;Load rightmost 
> 0306-   85 2C       STA   $2C           ;Stick in 2C
> 0308-   A9 09       LDA   #$09          ;Load vertical coord
> 030A-   A0 00       LDY   #$00          ;load horizontal coord
> 030C-   20 19 F8    JSR   $F819      ; call HLIN
>
> Should have a line of # through the screen and I don;t....
>  
> 0        
> *                                       

You still have to draw two HLINs because with one you're only setting
one half of the byte (the top or the bottom, depending on your
Y-coordinate).


-- 
--
Jerry     jerry+a2 at jpen.ca

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#47254

Hi,

Looking at the complexity of the HLIN approach, I'm wondering in which
aspect it is preferable over a single POKE into screen RAM. Especially
because AFAIK that POKE would work both in 40 and 80 col mode.

Regards,
Oliver

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#47260

Jerry Penner wrote:
 > "duhas...@gmail.com" <duhast6377@gmail.com> writes:
 >
 >> On Monday, May 9, 2022 at 6:40:09 PM UTC-4, Brian Patrie wrote:
 >>> Kent Dickey wrote:
 >>>> In article <f812d193-6a9e-4bfa...@googlegroups.com>,
 >>>> qkumba  wrote:
 >>>>> HLINE and VLINE don't scroll.
 >>>>
 >>>> To give a little more detail, try the following:
 >>>>
 >>>> 10 FOR I = 0 TO 23
 >>>> 20 COLOR= 3
 >>>> 30 HLIN 0,39 AT I * 2
 >>>> 40 COLOR= 10
 >>>> 50 HLIN 0,39 AT I * 2 + 1
 >>>> 60 NEXT
 >>>> 70 FOR I = 1 TO 10000000
 >>>> 80 NEXT
 >>>>
 >>>> The HLIN (and VLIN and PLOT) commands work on the text screen,
 >>>> if you don't give GR.
 >>> Better yet, write directly to the colour mask byte:
 >>>
 >>> 10 FOR I = 0 TO 47
 >>> 20 POKE 48,163
 >>> 30 HLIN 0,39 AT I
 >>> 40 NEXT
 >>> 90 ON PEEK(49152) < 128 GOTO 90 : POKE 49168,.
 >>>
 >>> (That last line just waits for a key, and clears it.)
 >>>
 >>> Or (on a machine with MouseText):
 >>>
 >>> 10 PRINT CHR$(17); : POKE 49167,. : TEXT
 >>> 21 FOR X = 0 TO 38 STEP 2
 >>> 22 POKE 48,86 : VLIN 0,47 AT X
 >>> 23 POKE 48,87 : VLIN 0,47 AT X + 1
 >>> 24 NEXT
 >>> 90 ON PEEK(49152) < 128 GOTO 90 : POKE 49168,.
 >>>
 >>> (Line 10 ensures 40 columns, alt charset, text mode.)
 >>
 >> Ok I tried the BASIC versions and they work like I want, but
 >> I tried to right a little assembly program to test it and I
 >> can't get it to work.
 >>
 >>
 >> *300L
 >> 0300-   A9 A3       LDA   #$A3       ;Load "#"
 >> 0302-   85 30       STA   $30           ;Stick in color
 >> 0304-   A9 27       LDA   #$27         ;Load rightmost
 >> 0306-   85 2C       STA   $2C           ;Stick in 2C
 >> 0308-   A9 09       LDA   #$09          ;Load vertical coord
 >> 030A-   A0 00       LDY   #$00          ;load horizontal coord
 >> 030C-   20 19 F8    JSR   $F819      ; call HLIN
 >>
 >> Should have a line of # through the screen and I don;t....
 >>
 >> 0
 >> *
 >
 > You still have to draw two HLINs because with one you're only
 > setting one half of the byte (the top or the bottom, depending
 > on your Y-coordinate).

Which is why i prefer to use VLIN.  (Though, from ml, either way is fast 
enough not to see the dirt that your eye can catch with HLIN from BASIC 
at 1 MHz.)

   0300-   A9 A3       LDA   #$A3    ;"#"
   0302-   85 30       STA   $30     ;to colour mask byte
   0304-   A9 2F       LDA   #$2F    ;bottom of line
   0306-   85 2D       STA   $2D
   0308-   A0 27       LDY   #$27    ;start column
   030A-   A9 00       LDA   #$00    ;top of line
   030C-   20 28 F8    JSR   $F828   ;VLINE
   030F-   88          DEY           ;next column
   0310-   10 F8       BPL   $030A
   0312-   60          RTS

And, since (contrary to my earlier assumption) the DGR support in 
AppleSoft (IIc, IIc+ ,IIgs) doesn't seem to apply to the machine 
language PLOT, HLINE, and VLINE calls, you can (with 80STORE enabled, of 
course) throw the PAGE2 switch and call this again, to fill the auxmem 
columns.

   *C055:0 n 300g n C054:0 n 300g

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#47243

> Or not scrolling I guess. I want to fill a the text screen with a character, in assembly. I'm using COUT, but the last character will cause the screen to scroll up one line and leave a line blank at the bottom. Is there a good way to prevent this beside printing everything but the last character and then directly sticking the last character into screen memory?

The simplest way I have seen so far is to increase the vertical and horizontal window sizes.

Increase $21 by 1 and $23 by 1 of zero page, set your htab and vtab then print your character to the bottom right hand corner using COUT.  And reset $21 and $23 back to normal.

Try this:

0300:A9 17 20 5B FB A9 27 85
0308:24 E6 21 E6 23 A9 C1 20
0310:ED FD C6 23 C6 21 A9 14
0318:20 5B FB 4C 8E FD 00 00
                                       

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#47244

On 7 May 2022, duhas...@gmail.com wrote

> Or not scrolling I guess. I want to fill a the text screen with a character, in assembly. I'm using COUT, but the last character will cause the screen to scroll up one line and leave a line blank at the bottom. Is there a good way to prevent this beside printing everything but the last character and then directly sticking the last character into screen memory?

As you are working in assembly, you could do as I did with Spectrum when I had a similar problem, and simply copy the screen code, and adapt it as necessary...

You can find the code in a //e manual.

Cheers - Speccie

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#47261

	ORG $0300
	LDA #$A3
	LDX #$78
loop
	DEX
	STA $400,X
	STA $480,X
	STA $500,X
	STA $580,X
	STA $600,X
	STA $680,X
	STA $700,X
	STA $780,X
	BNE loop
	RTS

0FORI=768TO799:READB:POKE
I,B:NEXT:DATA169,163,162,120,202,157,0,4,157,128,4,157,0,5,157,128,5,157,0,6,157,128,6,157,0,7,157,128,7,208,229,96
1 C =  ASC ("#")
2  POKE 769,C + 128: CALL 768
3  WAIT 49152,128: POKE 49168,0
4  POKE 37,255

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