Path: utzoo!mnetor!uunet!husc6!rutgers!sunybcs!boulder!tramp!williamm
From: williamm@tramp.Colorado.EDU (Michael Williams)
Newsgroups: comp.sys.apple
Subject: Re:  (Scrolling)
Message-ID: <5030@sigi.Colorado.EDU>
Date: 23 Mar 88 21:47:34 GMT
References: <8803191758.AA03635@tcgould.TN.CORNELL.EDU>
Sender: news@sigi.Colorado.EDU
Reply-To: williamm@tramp.Colorado.EDU (Michael Williams)
Organization: University of Colorado, Boulder
Lines: 30
Summary: Yes

In article <8803191758.AA03635@tcgould.TN.CORNELL.EDU> halp@TCGOULD.TN.CORNELL.EDU ("Bruce P. Halpern") writes:
>RE: SCROLLING
>
>The ad for ProTerm 2.0 in the April 1988 _A+_ includes scrolling of all 
>information that comes across the monitor screen (called SCROLLBACK), with 
>the limit being the amount of memory installed. ProTerm 2.0 is said to work 
>on ][e, ][c, and ][gs. Does this suggest that any of these ][ can scroll is 
>the appropriate software is supplied?
>
>  |  Bruce P. Halpern  Psychology & Neurobiology & Behavior Cornell Ithaca |

   Scrolling can be hardware dependant, as in the case of many existing t
terminals, whereby the last n lines passing the screen remain in RAM allocated
specifically for this purpose.  In this type of setup, scrolling keys will be
provided for viewing the various portions of the 'scroll RAM.'
   However, the Apple // is NOT one of these machines.  If scrolling is
desired, it must be implemented in the software.  All that is needed to
do this is (as with terminals) allocate an area of memory for the last
n bytes viewed/whatever.  Something like this can be done on -any- machine,
and should be fairly straightforward (easy to say, since I haven't actually
tried).  Within the program, there will routines which display given portions,
according to where in the scroll RAM the pointer presently exists.

  Hope this helps,
  -Remo

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