From: jerry@cs.mcgill.ca (Gerald (Jerry) KUCH)
Newsgroups: alt.games.sf2
Subject: Re: More gripes on sf2 for ibm
Date: 11 Dec 92 19:37:40 GMT
Organization: SOCS - McGill University, Montreal, Canada

In article <jon.taylor.53.723846151@uuserv.cc.utah.edu> jon.taylor@uuserv.cc.utah.edu (JON M. TAYLOR) writes:
>In article <1g0k9gINNsmh@usenet.INS.CWRU.Edu> ap005@cleveland.Freenet.Edu (Aaron Lukacsko) writes:
>>From: ap005@cleveland.Freenet.Edu (Aaron Lukacsko)
>>Subject: Re: More gripes on sf2 for ibm
>>Date: 7 Dec 1992 22:47:11 GMT
>>
>>In a previous article, epasls@kuhub.cc.ukans.edu () says:
>>
>>You're right, what can be done in one clock cycle isn'y as important as
>>what can be done overall.  Apples and amigas and such DO have chips
>>built in for sprites and such, however, every single game I have for my
>>PC blows away anything I had for my apple (I had a gs, the "top of the
>
>	Dude, the apple systems are 13 years old.  OF COURSE the PC will 
>blow them away.

The PC is 11 years old... what's your point?

BTW, in the original post, I'm not sure which Apples the writer was talking
about.  The original Apple ][ graphics system looks and feels a lot like
the PC system.  Lower resolution and fewer colors, true, but there's the same
sort of dearth of any particularly fancy hardware support for game and
animation type features.

The Amiga and C64 which have been mentioned in the thread so far look a
bit more like:

C64:
----
	320 x 200 screen display

	16 colors (simultaneously displayable)

	8 24 pixel by 21 pixel sprites.  Each one can be single color
	(color chosen freely from the 16 system colors) or multi-color
	with a transparent color, a body color unique to that sprite,
	and two other colors shared by all sprites that are indirected
	from a couple of registers on the 6566 VIC-II chip.  Multicolor
	sprites have half the horizontal resolution.  Sprites can also
	have their width and height independently doubled (by magnify-
	ing pixels, no resolution increase) by the video chip.

	Redefinable character sets allowing 1 color per character cell,
	or four colors in a scheme similar to that for sprites.

	Raster interrupt capabilities.  At given screen lines, interrupts
	can be set to occur to change video display modes, reprogram 
	sprite registers to re-use already used sprites further down the
	screen, update the playing of background sound effects, etc.

	6581 SID (Sound Interface Device) chip.  Provides 3 voices of 
	mono audio with reasonably good waveform and envelope control.
	High, low, and band pass filters.  ADSR control.  Four pre-
	set waveforms (sawtooth, pulse, triangle and noise).  Takes 
	very little CPU time to run music through this thing... far 
	less than, for instance, continually pounding on a PC or Apple
	][ speaker to try to get a continuous tone out of it.

	Overall the machine had a fair bit of hardware to take game
	and animation and music type activities away from the CPU.  The
	Atari 8-bits were as sophisticated in these respects, and in some
	ways a bit nicer than the 64, but picking a clear winner would
	have been hard.  The Apple ][ was the clear loser in this respect,
	given its 8 color hi res (280 x 192) graphics where two of the 
	colors were white, lack of sprites, cheap-o-transducer-speaker
	sound system, lack of redefinable character sets (good for fast
	graphics with lots of repeated subunits), etc.

Amiga (Old ECS, not new AGA):
-----------------------------

	Resolutions variable from 320 x 200 up to 640 x 400 (NTSC).
	320 x 256 up to 640 x 512 (PAL).  Both can be increased somewhat
	in either direction by using overscan which increases the screen
	image's size by using up more of the border space toward the 
	edges of the monitor.  (AGA increases these to 800 x 600, more
	with overscan used).

	Colors per screen 2,4,8,16,32,64, or 4096 depending on resolution
	and attributes selected.  Color depth is not entirely orthogonal
	across all modes.  (AGA changes this and increases the maximum
	colors per screen up to 262,144 using the HAM8 mode or 256 in
	other modes, and allows any color depth at any resolution).

	Bit blitter.  One of the Amiga custom chips includes a fairly
	sophisticated bit block mover.  The blitter is three source 
	and supports 256 minterms that allow two sources to be combined
	in different ways as they are blitted into a third chunk of
	video memory.  The blitter and CPU can operate concurrently,
	provided they do not attempt to access the same memory.  The
	blitter can be used to produce fast BOBs (blitter objects)
	and VSprites (virtual sprites, separate from the regular
	sprite hardware) for animation.

	Sprites.  The Amiga dedicates 8 DMA channels to sprites.  Each
	sprite is 16 pixels wide (larger on AGA).  Sprites are normally
	four color, although a system supported "sprite attachment" 
	scheme allows them to be 16 color.  Sprites are refreshed 
	completely independently from the background.

	Display coprocessor (copper).  The copper is a three instruction
	chip for supporting the graphics display.  It can be used in ways
	similar to the raster interrupts on the C64 (called display list
	interrupts on the old Atari 8-bit machines).  A given scan line
	on the screen display can be waited for as the copper list is
	executed.  When it's reached, new data can be moved into video
	chip registers, thus permitting palette changes, re-use of 
	previously used sprites, etc.

	Audio.  Four channels, 8-bit stereo wave-table synthesis.  More
	complicated than ColecoVision/C64/SoundBlaster style FM synthesis.

These are both less widely known and understood than the PC, so I won't
bother puking up any PC information.  This will probably turn out to be
a completely wrong assumption given some of the pathological ignorance
of even the PC's video hardware that we've seen in this group.  That CPU
debate was a classic... "no the 386 is 16-bit!  No it's 32-bit but it's
running an 8-bit OS!"  Buddha on a Bagel... where did those guys get 
that stuff?  Has no one ever programmed in their lives?

>>line apple 2")Games like wing commander, ultima 6 and , and a bnch of
>>others come to mind.  As for sf2ibm, I tooo am impressed with it and
>>wouldn't mind having it finished with the way the graphics are (just add
>>sound)  Although a little choppy and somewhat not sharp, its pretty
>>good.  Also, I wasn't meaning anything about the source code bit, I was
>>merely thinking it would be great to see it, further more, you don't
>>even know me or know how good I program so why even talk about it???
>>The 91 date is probably the release date of the game, OR the game could
>>have been released in Japan, or Korea before it was released here.
>>
>>Also, for the games, I thought what you do about pc games, but they
>>really can beat the shit out of apple games (and most amigas but I'm
>
>	The ONLY thing that PC's *had* over the Amiga was more colors at 
>more resolution.  Hell, they still have analog joysticks!

True.  But not anymore, as of the Amiga's new AGA chipset.  It will be
interesting to see if Commodore maintains chipset improvements and adds
RTG/DIG to their operating system at a reasonable rate.  Otherwise they
may get leapfrogged by the PC again in the resolution/colors arena.

>>impressed with the animation, hell, everyone knows ibm animation is
>>lacking...)

Except for those blinded by their own stupidity---there seem to be a fair
number of them in this group.  

Now I think I'll go get back to a 16-bit 386... or was that an 8-bit 386?
Hey... can the bozos who posted the above inaccuracies please explain what
it means for a chip to be an n-bit CPU?  It might go a long way toward 
understanding whatever psychological anomaly afflicts them.

>>Aaron
>>
>
>	-Jon


-- 
 Jerry Kuch (jerry@cs.mcgill.ca) | Wishing I were an emaciated chihuahua. 
 "I was wrong to play God.  Life is precious, not a thing to be toyed with.
  Now take out that brain and flush it down the toilet."
                  --- M. Burns  "Treehouse of Horror II"
Newsgroups: alt.games.sf2