jmdavis@ihlpm.UUCP (02/13/87)
) > ) > ) >program used a special timing loop to flip back to the text page ) >from the graphic page so that SINGLE CHARACTERS on the text page ) >could be displayed on the graphic page. In the animation the ) > ) > Mike Davis ) > ) ) =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= ) ) If I recall, Applevision, as it was called, used a character generator. ) I think that this can be shown when a user halts the program via ) a break. The integer basic break notice appears as well as the prompt. ) ) paul nakada ) ) =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= ) ) ) ) WROGO, MIKE! ) ) It is not possible to access the page switches fast enough to display ) the width of a single character. The minimum width is 1/4 (maybe ) 1/6) of the screen. ) ) Chris Schumann schumann@puff.wisc.edu ) ) Well, maybe I was wrong about Applevision, at any rate I have the following for my defense. 1) There really was an interview with this bishop fellow where he told you how to flip pages (or something) so that a line of text on the text screen can appear on the hires screen. (I thought a single char was too little an amount but wasn't sure.) If this causes still more doubts then I guess I will have to go dig that article up and post it. 2) the reason that I thought this method was used in Applevision was due to the characters O and HOME SWEET HOME appearing on the text screen after hitting reset in the same position that thye occupied on the graphic screen. The bishop article I reference includes a program to illustrate the method. I have run it and can state that it puts lines (how many I don't remember) on the hires screen without a character generator. Mike Davis After beaten into submission our hero quietly returns to his lair where a warm comfy bed and a glass of milk await him.
ln63wzb@sdcc7.UUCP (02/14/87)
In article <1218@husc6.UUCP> nakada2@husc4.UUCP (paul nakada) writes: >In article <888@ihlpm.UUCP> jmdavis@ihlpm.UUCP (Davis) writes: >>Just so the old folklore of the Apple doesn't die I thought I would >>mention a program by ???? Bishop where a living room with TV >>is drawn and a man appears on the tiny TV screen and dances. >If I recall, Applevision, as it was called, used a character generator. Bob Bishop was the early master of Apple hi-res graphics; Applevision is what sold me on the II. He did use a hi-res character generator for printing text on the graphics screen. His other "milestone" programming techniques on the II included cassette port sound digitizing and voice recognition, the first commercial fill routines/dithering on the Apple (MicroPainter), and documentation of the "half-dot shift" effect in hi-res (even before Apple got it right.) Anyone know what he's been up to in the last five years? Grobbins.
rms@meccts.UUCP (02/14/87)
In article <890@ihlpm.UUCP> jmdavis@ihlpm.UUCP (Davis) writes: > where he told you how to flip pages (or something) so that > a line of text on the text screen can appear on the hires > screen... > 2) the reason that I thought this method was used in > Applevision was due to the characters O and HOME SWEET HOME > appearing on the text screen after hitting reset in the > same position that they occupied on the graphic screen. Applevision used a character generator which put text on both the hires and text screens. (This had also confused me for years.) You can display text on the graphics screen if your timing routines work just right. (That is, turn on graphics display, wait, turn on text display, wait, turn on graphics...etc.) This is used often on the Commodore 64 to do neat things. Roger Shimada rms@meccts.UUCP ihnp4!meccts!rms
ln63wzb@sdcc7.UUCP (02/15/87)
In article <890@ihlpm.UUCP> jmdavis@ihlpm.UUCP (Davis) writes: >The bishop article I reference includes a program to illustrate >the method. I have run it and can state that it puts lines (how >many I don't remember) on the hires screen without a character >generator. > Mike Davis Bob Bishop did publish an article on how to flip pages to mix text and graphics. But since his sample programs did it with timing loops not tied to the redrawing of the screen, flicker was horrible. He didn't have any choice; no information on the state of the video circuitry is available to software in the Apple II and II+. Does the //e allow software to detect the video retrace situation? If so, has anyone used it to mix text/lo-res/hi-res lines on the screen? Grobbins ln63wzb@sdcc7.ucsd.edu
hsu@eneevax.UUCP (02/16/87)
In article <875@sdcc7.ucsd.EDU> ln63wzb@sdcc7.ucsd.edu.UUCP (Grobbins) writes: > >Bob Bishop did publish an article on how to flip pages to mix text >and graphics. But since his sample programs did it with timing >loops not tied to the redrawing of the screen, flicker was horrible. >He didn't have any choice; no information on the state of the video >circuitry is available to software in the Apple II and II+. Actually, I seem to remember somebody publishing a technique that kept staring at a supposedly unimportant address, watching for some sequence (something like three `04's and something else) and flipping THEN. Never did look at it closely enough to see how it worked. >Does the //e allow software to detect the video retrace situation? >If so, has anyone used it to mix text/lo-res/hi-res lines on the >screen? > >Grobbins There is a retrace flag available; no, I don't remember the address. -dave -- David "bd" Hsu hsu@eneevax.umd.edu <or> seismo!mimsy!eneevax!hsu EE Computer Facility, Maryversity of Uniland, College Park, MD 20742