Re: Screen Scrolling

From	Brian Patrie <bpatrie@bellsouth.spamisicky.net>
Newsgroups	comp.sys.apple2
Subject	Re: Screen Scrolling
Date	2022-05-09 17:40 -0500
Organization	an elaborate system of piles and accidents
Message-ID	<t5c581$acm$1@gioia.aioe.org> (permalink)
References	<b2b6a5dc-de2f-4ac0-ba41-70eb215dff98n@googlegroups.com> <5e80af7d-ec2f-4627-9e96-894c057657a3n@googlegroups.com> <f812d193-6a9e-4bfa-b896-8c6fdcef1f44n@googlegroups.com> <t5a3r0$eq8$1@dont-email.me>

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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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Thread

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

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