From: hawk@fac13.ds.psu.edu (Prof. Richard E. Hawkins) Newsgroups: comp.lang.asm370,alt.folklore.computers Subject: atari display [was: mainframe question] Followup-To: alt.folklore.computers Date: 9 Nov 2001 17:39:02 GMT Organization: Penn State University, Center for Academic Computing Lines: 33 Distribution: inet Message-ID: <9sh4bm$rr0@r02n01.cac.psu.edu> References: <3BE9039B.99965E4D@ev1.net> <8phds9.l68.ln@escape.shannon.net> <3BEB3251.1E035672@ev1.net> NNTP-Posting-Host: fac13.ds.psu.edu X-Newsreader: trn 4.0-test76 (Apr 2, 2001) Originator: hawk@fac13.ds.psu.edu (Prof. Richard E. Hawkins) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.ifi.unizh.ch!news.imp.ch!news.imp.ch!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!news.cis.ohio-state.edu!news.ems.psu.edu!news3.cac.psu.edu!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:94112 [Followup limited to alt.folklore.computers] In article <3BEB3251.1E035672@ev1.net>, Charles Richmond wrote: >Charles Shannon Hendrix wrote: >> Easter Front was pretty amazing for it's time though. I spent a few >> hours on it. >Yes, it is *amazing* what could be done with the old 8-bit Atari. >It had a kind of graphics co-processor in it. IIRC, that is how >Crawford got the map to scroll across the screen so well. The 400/80 used a display processor which was running slightly more often than the main processor--the 1.8Mhz clock was only when it was running. Anyway, you wrote a display "list", in which you described the memory locations to be used by each line of the display. You could get such a scrolling by incrementing the starting values of each line. You could also shake the entire screen quite easily for an earthquake. There was an incredibly dull game to run a nuclear reactor. Being successful was trivial. It was far more interesting to see how fast you could cause a meltdown, which led to the quake . . . hawk -- What part of "non-negotiable" didn't you understand? /"\ ASCII ribbon campaign dochawk@psu.edu Smeal 178 (814) 375-4700 \ / against HTML mail These opinions will not be those of X and postings. Penn State until it pays my retainer. / \ ###### From: Greg Menke Newsgroups: alt.folklore.computers Subject: Re: atari display [was: mainframe question] Date: 09 Nov 2001 14:02:35 -0500 Organization: MindSpring Enterprises Lines: 27 Sender: gregm@europa.pienet Distribution: inet Message-ID: References: <3BE9039B.99965E4D@ev1.net> <8phds9.l68.ln@escape.shannon.net> <3BEB3251.1E035672@ev1.net> <9sh4bm$rr0@r02n01.cac.psu.edu> NNTP-Posting-Host: a5.f7.5b.2e X-Server-Date: 9 Nov 2001 19:01:59 GMT X-Newsreader: Gnus v5.7/Emacs 20.7 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!newscore.univie.ac.at!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!cpk-news-hub1.bbnplanet.com!lsanca1-snf1!news.gtei.net!newsfeed2.earthlink.net!newsfeed.earthlink.net!news.mindspring.net!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:94130 > Anyway, you wrote a display "list", in which you described the memory > locations to be used by each line of the display. You could get such a > scrolling by incrementing the starting values of each line. You could > also shake the entire screen quite easily for an earthquake. It was also possible to change graphics modes on a per scanline basis, and do some interesting coloring by careful timing and tweaking the color hardware just as the tv scanline passed the spot you were interested in. > There was an incredibly dull game to run a nuclear reactor. Being > successful was trivial. It was far more interesting to see how fast you > could cause a meltdown, which led to the quake . . . SCRAM is its name I believe. It was written in a combination of Atari Basic and assembly. The cassette version was handy because it was hackable, I snagged a couple techniques they used for various graphics by breaking in and un-obfuscating it. At the time my dad used it as a source of ideas for his own somewhat fancier reactor simulation program. Happily there are quite a number of people still hacking around with old Atari machines, in the US and Europe. Gregm