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.