nagendra@bucsf.bu.edu (nagendra mishr) (02/04/91)
Does anyone remember what the memory location is that tells what page you're drawing on? I wanted to do some 2 page animation with the old hires modes. and I remember that it was something like poke -16xxx,32 to draw on page 1 and poke -16xxx,64 to draw on page2 without showing those screens. but I can't seem to remember the location numbers. Does anyone remember? nagendra@bucsf.bu.edu **************************************************************************** * Destiny is a birth-right. | nagendra@bucsf.bu.edu * * Not wanting it is a decision. | Junior at Bonston University * * Not realizing it is failure. | computer science * ****************************************************************************
dlyons@Apple.COM (David A. Lyons) (02/05/91)
In article <NAGENDRA.91Feb4032746@bucsf.bu.edu> nagendra@bucsf.bu.edu (nagendra mishr) writes: >Does anyone remember what the memory location is that tells what page >you're drawing on? [...] I didn't remember offhand, but I remembered that CALL 62454 would fill the current screen with the last used color. 62454 is $F3F6, so I looked and found it using $E6 as the high byte of the pointer to the memory to fill. $E6 is 230, so you want to POKE 230,32 to draw to page 1 and POKE 230,64 to draw to page 2. -- David A. Lyons, Apple Computer, Inc. | DAL Systems Apple II System Software Engineer | P.O. Box 875 America Online: Dave Lyons | Cupertino, CA 95015-0875 GEnie: D.LYONS2 or DAVE.LYONS CompuServe: 72177,3233 Internet/BITNET: dlyons@apple.com UUCP: ...!ames!apple!dlyons My opinions are my own, not Apple's.
seah@ee.rochester.edu (David Seah) (02/05/91)
In article <NAGENDRA.91Feb4032746@bucsf.bu.edu> nagendra@bucsf.bu.edu (nagendr! >Does anyone remember what the memory location is that tells what page >you're drawing on? Zero page location $E6 (230 decimal) tells you what memory page that Applesoft will use to draw on. For Hires Page 1, poke 230,32. For Hires Page 2, poke 230,64. >I wanted to do some 2 page animation with the old hires modes. and I >remember that it was something like poke -16xxx,32 to draw on page 1 and >poke -16xxx,64 to draw on page2 without showing those screens. >but I can't seem to remember the location numbers. Here's something out of the ancient book, "Apple Graphics and Arcade Game Design" by Jeffrey Stanton: 5 X1=0:Y1=0 10 rem clear both screens 20 home:hgr:hgr2:hcolor=3 30 rem now looking at page2 40 rem set drawing mode pointer (E6) to screen #1 50 POKE 230,32 51 rem clear screen #1 52 call 62450 60 for i=1 to 35 70 x2=int(rnd(1)*280) 80 y2=int(rnd(1)*192) 90 hplot x1,y1 to x2,y2 100 x1=x2:y1=y2 110 next i 120 rem look at screen #1 full screen 125 poke-16300,0:poke-16302,0 130 rem set drawing mode pointer (e6) to screen #2 135 POKE 230,64 136 rem clear screen#2 137 call 62450 145 for i=1 to 35 150 x2=int(rnd(1)*280) 160 y2=int(rnd(1)*192) 170 hplot x1,y1 to x2,y2 180 x1=x2:y1=y2 190 next i 200 rem look at screen #2 210 poke -16299,0 230 goto 50 All...what memories! :-) -- Dave Seah ^..^ | Analog Design Automation Research Group - Graphics & GUI | | University of Rochester, Dept. of Electrical Engineering | ////// Internet: seah@ee.rochester.edu ////// America Online: AFC DaveS //////
ART100@psuvm.psu.edu (Andy Tefft) (02/05/91)
In article <48811@apple.Apple.COM>, dlyons@Apple.COM (David A. Lyons) says: > >I didn't remember offhand, but I remembered that CALL 62454 would fill the >current screen with the last used color. 62454 is $F3F6, so I looked and >found it using $E6 as the high byte of the pointer to the memory to fill. > >$E6 is 230, so you want to POKE 230,32 to draw to page 1 and POKE 230,64 >to draw to page 2. That's one way of finding out :-) When's the last time you could do something like this on a mac? Of course, 230 is easier to remember than the number you did!
marekp@pnet91.cts.com (Marek Pawlowski) (02/05/91)
As a follow-up question to that, could someone list all the important memor
locations for graphic page flipping. Such as the ones to diplay page x, and
draw on page x, etc?
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/* { Ph: (416) 884-4501 4-8pm EDT } generic!pnet91!marekp@zoo.toronto.edu */ericmcg@pnet91.cts.com (Eric Mcgillicuddy) (02/05/91)
>$E6 is 230, so you want to POKE 230,32 to draw to page 1 and POKE 230,64 >to draw to page 2. > >-- >David A. Lyons, Apple Computer, Inc. | DAL Systems POKE 230,96 draws to Page 3 also. I wonder were POKE 230,128 draws? On the wall maybe? :) POKE the colour number into 228 if you do not like the las colour plotted. Black is 0 or128, White is 127 or 255, Green =42, Violet = 85, Orange = 170 and Blue =213. Note that these numbers equate to the bit patterns required to generate these colours. UUCP: bkj386!pnet91!ericmcg INET: ericmcg@pnet91.cts.com
daveh@ccwf.cc.utexas.edu (David H. Huang) (02/05/91)
In article <452@generic.UUCP> marekp@pnet91.cts.com (Marek Pawlowski) writes: >As a follow-up question to that, could someone list all the important memor >locations for graphic page flipping. Such as the ones to diplay page x, and >draw on page x, etc? To select graphics screen => -16304 To select text screen => -16303 To select full screen graphics => -16302 To select graphics/text => -16301 To select page 1 => -16300 To select page 2 => -16299 To select lo-res => -16298 To select hi-res => -16297 and as other people have pointed out, POKE 230,32 to draw on page 1, POKE 230,64 to draw on page 2. Those softswitches are from memory, but I think I got them all right. You can do the conversion to hex yourself if you want... >/* Marek Pawlowski, marekp@{generic|pnet91|bkj386|torag|aunix}.uucp [CONT] */ >/* {albert|wookumz|apple-gunkies|pogo|churchy|geech|spiff|mole}.ai.mit.edu */ >/* President, Intelligent Twist Software, 250 Harding Blvd, PO BOX 32017 */ >/* Richmond Hill, Ontario, L4C 9M7, CANADA. An ideal route is as follows: */ >/* { Ph: (416) 884-4501 4-8pm EDT } generic!pnet91!marekp@zoo.toronto.edu */ -- David Huang | Internet: daveh@ccwf.cc.utexas.edu | "My ganglion is stuck in UUCP: ...!ut-emx!ccwf.cc.utexas.edu!daveh | a piece of chewing gum!" America Online: DrWho29 |