Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!zaphod.mps.ohio-state.edu!uwm.edu!ogicse!pdxgate!eecs!bairds From: bairds@eecs.cs.pdx.edu (Shawn L. Baird) Newsgroups: comp.sys.amiga.programmer Subject: Re: Lemmings - a tutorial Part V (last) Message-ID: <2149@pdxgate.UUCP> Date: 30 Mar 91 23:05:04 GMT References: <23788@well.sf.ca.us> <23837@well.sf.ca.us> <781@tnc.UUCP> Sender: news@pdxgate.UUCP Lines: 57 mykes@amiga0.SF-Bay.ORG (Mike Schwartz) writes: >Sorry to paste this whole thing again, but it is the best article >done so far. [ ... some stuff deleted ... ] >No sources will be posted here, but I have done a small game (in 3 >days in assembler) that I do intend to publish source code to >at a future date. And believe it or not, it does not kill the OS >to the point that it can't be restored. In other words, it runs from >DOS and returns to DOS, but it does NOT multitask. [ ... some stuff deleted ... ] >When the Amiga first boots, it asks for a workbench disk. If you >have an autobooting hard drive and a bootable floppy is inserted, >the machine will boot from the floppy. In any case, the ROM Kernel >loads what is called the boot program from track 0 of the floppy >disk into RAM and does a JSR to it. The standard Amiga OS bootsector >program simply opens dos.library and then does an RTS and the system >continues to boot up into the normal Operating System. >Well, I wrote my own boot sector program that just doesn't return >to the OS. In this boot sector program, I call several ROM Kernel [ ... rest deleted ... ] I'm a bit confused here. First you say it runs from DOS and returns to DOS. Then you say you wrote your own boot sector program that doesn't return to the OS. Which of the two is true? I suspect that, although you save the state of the OS there really isn't a reason to do so. Not only this, but using a custom bootblock will render the game only bootable on floppy disks and (from the descriptions of doing all of the floppy reading on your own) the disk itself will not be in AmigaDOS format, therefore there will be no way to install your program on a hard drive. What is the point of keeping the OS state when even if you did return to it the user has had to reboot at least once just to get started? Basically, it sounds like most other games I've seen. Granted, you attempt to do things in a correct and compatible way across all Amigas, but I already believe that someone who doesn't do this ought to be shot. I think Mike Farren's point was, correct me if I'm wrong, was that games like Lemmings could be made to take over the OS or multitask with the point being to be able to do things like install it on a hard drive. While avoiding the operating system routines may sometimes be helpful, I sincerely doubt that you find the routines so horrible that you avoid using them when running programs like your editor, your assembler, etc. You can't tell me that fast blitting is impossible when the OS is still intact. Look at CED. It blazes it's scrolling along at a very fast clip (and I've noticed that the rest of the machine slows down accordingly), probably by OwnBlitter() for long periods of time. --- Shawn L. Baird, bairds@eecs.ee.pdx.edu, Wraith on DikuMUD The above message is not licensed by AT&T, or at least, not yet.