Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!ucbcad!ucbvax!LAUCOSC.BITNET!POSTMAST From: POSTMAST@LAUCOSC.BITNET Newsgroups: comp.sys.atari.st Subject: (none) Message-ID: <8801060745.AA12409@ucbvax.Berkeley.EDU> Date: 6 Jan 88 07:45:42 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 118 X-Unparsable-Date: 6-JAN-1988 02:41:49.13 Mail to 85102368@LAUCOSC could not be delivered for the following reason: %MAIL-E-NOSUCHUSR, no such user 85102368 Original text follows: Received: from LAUVAX01(MAILER) by SMTP forwarder for 85102368@LAUCOSC; 6-JAN-1988 02:40:03.97 Received: From CANADA01(MAILER) by LAUVAX01 with RSCS id 2213 for MAILER@LAUVAX01; Wed, 6 Jan 88 02:39 EST Received: by CANADA01 (Mailer X1.24) id 2207; Wed, 06 Jan 88 02:34:40 EDT Date: Mon, 4 Jan 88 12:44:50 PST Reply-To: Info-Atari16@Score.Stanford.edu Sender: INFO-ATARI16 Discussion From: Info-Atari16 Digest Subject: Info-Atari16 Digest V88 #2 To: Maury Markowitz <85102368@LAUCOSC> Info-Atari16 Digest Monday, January 4, 1988 Volume 88 : Issue 2 This weeks Editor: Bill Westfield Today's Topics: Re: Multi-tasking? A Nightmare... Re: HELP! the real advantage of multi-tasking. Failing Disk Drive & Strange TPA pointer drive problems Re: Microsoft Write ... Re: Multi-tasking? A nightmare... Re: about ST disk drives (and media change) Cheap Harddiscs ---------------------------------------------------------------------- Date: 23 Dec 87 22:13:59 GMT From: well!ewhac@hplabs.hp.com (Leo 'Bols Ewhac' Schwab) Subject: Re: Multi-tasking? A Nightmare... To: info-atari16@score.stanford.edu [ Followups to alt.flame, where it rightfully belongs. ] Someone writes: >> I'm still waiting to see if someone can come up with a use for TRUE >> multitasking that a typical home user would find very handy but that >> cannot be satisfied by a simple 'carousel' approach. There probably >> are some, especially with message-passing, etc., but none have been >> posted yet (except for people waiting for their compilers to finish -- >> they just need faster integrated compilers, though :) >> >> Robert Gardner >> Here's a real-world example. Note that this is from the programmer's perspective, not the user's. As you will see later, this is irrelevant. The specifications are as follows: You are to design a space invaders-type game. There is one spaceship at the top of the screen, and a gun at the bottom. The spaceship moves across the top of the screen from left to right; as it does so, it "drops" letters forming words down the screen. As the user types on the keyboard, the program checks to see if the letter typed matches the one the gun is currently under. If so, the letter is shot and the gun moves one position to the right (to the next letter in the word. If they don't match, a short error signal is delivered to the user. The screen will look like this: --------------------------------------------------------------------------- ...<-=O=-> S P A C E W E L L C R A T H A N T H I S H A L L K I L L T H R I L L L A K E G R E A T A N P A R T D R A T S P A C E B E A T H E A R S E A D R E A A T H E R M A P T H A N F O R H E A R T | A /#\ --------------------------------------------------------------------------- The spaceship moves across the top of the screen at a fixed rate. When it reaches the end of the row, all the rows drop down one, and the ship returns to the left side. To make it more interesting, a range of colors in the spaceship are to be cycled, to make it look like it's spinning. The cycle rate is totally independent of any other regular rate in the program. Don't worry about winning or losing at this point; they'll complicate the issue. Now. Design this program, first on a system with multitasking, and then on a system without it. Discuss the design issues that need to be considered, and how you would address them under each environment. "Be specific; give examples." Whether or not the machine multitasks should be made invisible to the user; both versions should run the same as far as the user is concerened. -------- I designed this very program on the Amiga. I was porting the program from the Atari ST, working from the ST source code. Before posting my approach and ultimate solution to the problem, I want to see how others would address it. That is, if anyone cares..... [In the article titled "Re: Multi-tasking? A nightmare...", Dec 22, 1987,