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- Path: sparky!uunet!cbmvax!bagate!dsinc!spool.mu.edu!agate!doc.ic.ac.uk!warwick!uknet!yorkohm!minster!amc-a
- From: amc-a@minster.york.ac.uk
- Newsgroups: comp.sys.amiga.games
- Subject: RE: A1200 custom registers: ignorance punished.
- Message-ID: <728137628.28014@minster.york.ac.uk>
- Date: 27 Jan 93 12:27:09 GMT
- Organization: Department of Computer Science, University of York, England
- Lines: 59
-
- Article 21583 of comp.sys.amiga.games:
- Path: minster!yorkohm!uknet!pavo.csi.cam.ac.uk!doc.ic.ac.uk!agate!spool.mu.edu!uunet!cbmvax!chrisg
- In Article 21583 chrisg@cbmvax.commodore.com (Chris Green) writes
-
- [ lots of stuff he obviously knows a lot more than me about ]
-
- Well, aren`t I suitably slapped down! [%^(
-
- Apologies to everyone for the ill informed article I posted concerning the A1200
- chipregisters, and OS routines. I must admit to being a shameless hardware basher
- obsessed with speed at any cost. I DO get results though. I think the main problem
- I had (Note the past tense there =->) with the OS is that programming it looked too
- much like a high level language, and I`ve had some bad experiences with those.
- Like I said, I haven`t got a 1200 yet, nor any kind of documentation for it. When
- I DO (This weekend =-)) I`ll begin programming it with a fresh outlook on the
- subject of making things OS compatible (At least the commercial stuff). I`m sure
- I will still do a bit of hardware bashing in my spare time, however.
- I do still have a few troubling questions on my mind:
-
- Some games lend themselves very well to operating on different machines; Wing
- Commander being a very good example of this. Something like a platform game however
- with a more rigidly defined graphic system ain`t gonna handle the move too well, I
- expect.
-
- Sticking with the platform game scenario, what if I want to draw something to the
- screen, say a background block? From what you say I will have to go through the OS
- to draw it because future blitters may be totally different. On the A500 that would
- be too slow. I`m not being prejudiced here; my scrolling routine uses precisely two
- instructions per background block and is optimised down as far as I can go. Having
- to to use something like BlitBitmap would be heartrendingly slow. Am I going to go
- to all the trouble of making the rest of the game OS-and-upwardly compatible only
- to have it fall over on the A10000 because of the scroll routine? It`s such a NICE
- scroll routine too; it uses 70K (apprx) of screen memory and scrolls a 64 colour
- (6 bitplane) display at 16 pixels/frame in all directions in only 50 rasterlines.
- PLEASE tell me I don`t have to throw it away.
-
- Memory is another big worry of mine. With (I thought) some clever ideas I cut down
- the screen memory I need from 300K+ (For a 32colour screen) to 70K (for a 64 colour
- screen). This makes room for 3-4 more screenfulls of graphics; am I going to have to
- use it all up to keep the OS intact? This again would make the whole game impractical
- on anything under a 2meg chip machine.
-
- Whichever way I do things, I seem to lose out. Either I make my code as fast as
- possible to make the A500/600 version worthwhile, sacrificing compatibility and OS
- friendliness, or I pin my hopes on the 1200 and its successors and produce programs
- exclusively for them.
-
- If anyone has any answers to this dilemma (And please, no smug PC owners telling me
- to buy a 486) I would be glad to hear them.
-
- Again, apologies for speaking before I knew what I was about.
-
- Andy.
-
- ========================================================================================
- | `Call yourself a goalie? My auntie Vera could have saved that, and she`s in a coma.' |
- | a friend playing Sensible Soccer. |
- |______________________________________________________________________________________|
- The views represented herein are my own, and I can`t promise to make them coherent.
-