Article View: comp.sys.mac
Article #41880Re: Mac II graphics weirdities
From: Kelton Flinn
Date: Thu, 04 May 1989 04:23
Date: Thu, 04 May 1989 04:23
19 lines
1697 bytes
1697 bytes
In article <13121@paris.ics.uci.edu>, milne@ics.uci.edu (Alastair Milne) writes:
>Question for the day: I've got a mac II here and have found that certain
>graphics intensive programs (macpaint for the SE, Talking Moose, Dungeon
>of Doom) Draw everything ok except the working area (thing being drawn)
>which appears
>seriously smallified in four scaled down ~1"x1" squares spread out along
>the menu bar.
>
This is caused not by applications accessing memory at the wrong
address, but by accessing memory in the wrong FORMAT. The aforementioned
programs ASSUME that pixels consist of one bit, whereas in fact they
consist of 1, 2, 4 or 8 bits, depending on the graphics mode you set with
the Control Panel. Since the window frames and so on are drawn using
Quickdraw, they are drawn correctly. Anything the application does by
bypassing the ROM routines and accessing the memory directly comes out
wrong. Why do they do this? Generally speed. How do you fix it? Set the
monitor to monochrome using the Control Panel and it'll work perfectly,
unless they've broken even worse rules <grin>.
Kelton
Technical Details
Message-ID:
<212@kesmai.COM>Path:
arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!dogie.macc.wisc.edu!indri!aplcen!haven!uvaarpa!virginia!kesmai!kffReferences:
<1531@jhunix.HCF.JHU.EDU> <8264@chinet.chi.il.us> <492@biar.UUCP> <13121@paris.ics.uci.edu>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!dogie.macc.wisc.edu!indri!aplcen!haven!uvaarpa!virginia!kesmai!kff From: kff@kesmai.COM (Kelton Flinn) Newsgroups: comp.sys.mac Subject: Re: Mac II graphics weirdities Summary: Why there are little duplicate images... Keywords: Small, *4, Color Message-ID: <212@kesmai.COM> Date: 4 May 89 04:23:46 GMT References: <1531@jhunix.HCF.JHU.EDU> <8264@chinet.chi.il.us> <492@biar.UUCP> <13121@paris.ics.uci.edu> Distribution: usa Organization: Kesmai Corporation, Charlottesville, VA Lines: 19