The Kings Quest Mystery Solved
Great Hierophant
Quest, even in its booter versions is supposed to be capable of 16 colors,
why did it use the low resolution of 160x200?
Well, after examing all the evidence on the subject, here is what I believe
to be true:
IBM approached Roberta Williams sometime in 1982 or 1983 with the hardware
specs and
development tools for the PCjr. They wanted a killer app to sell the
reasonably expensive system. Here are the specs of the PCjr:
CPU Type: Intel 8088 8/16(20)bit
CPU Speed: 4.77MHz
Minimum System RAM: 64KB
Maximum System RAM: 128KB
Video RAM: Shared with system memory, 16 or 32KB depending on mode
Text Modes: 40x25x16; 80x25x16; 8x8 matrix
Graphic Modes: 160x200x16; 320x200x4; 320x200x16; 640x200x2; 640x200x4
Storage Capabilities: 5.25 360KB Floppy
Sound Capabilities: 4 Voices, 3 Square Wave Channels, 1 White Noise Channel
Input Devices: 63 Key Keyboard; 2-button Analog Joystick
Expansion: 1 Dedicated RAM slot; 1 Dedicated Modem Slot; 1 Sidecar
Port; 2
64KB Cartridge Ports
Connectors: 1 Audio, 2 Joystick, 1 RGB, 1 Composite Video; 1 Lightpen;
1
Cassette; 1 Serial Port; 1 IR Keyboard Port; 1 Wired
Keyboard Port
Operating System: IBM PC-DOS 2.1
The IBM PCjr. was designed like a Commodore 64, not meant to be exandable
but connectable. King's Quest for the IBM PCjr. requires an extended model
of the PCjr. with 128KB of RAM. At the time, that was all the machine was
supposed to be expandable to. So that was what she designed for. However,
the IBM PCjr. is a bit crippled. 128KB of RAM is very light for something
that has to run DOS, BIOS routines, and 16-32KB of the RAM is taken by the
video subsystem. This leaves 112-96KB for user programs if the game uses its own
booting routines instead of DOS.
Lets suppose that the system was going to use the most colorful resolution,
320x200x16. This is the same as EGA in terms of number of colors on screen,
16, and the resolution, 320x200. A full page of EGA requires 32KB of video
RAM because every pixel color is designated by 4 bits. Setting the
video subsystem in the PCjr. would also take a full 32KB away from Williams.
However, if you only used the 160x200x16 resolution, you could get very
impressive results, surpassing the Commodore 64. (Everyone else then used
stretched resolutions anyways for games, where the vertical resolution is greater
than the horizontal resolution.) You would also have 112KB
of RAM to play with. The Commodore 64 has a similar resolution due to
doubling of pixels. The Commodore 64 was the computer to beat in 1982 and
1983 for graphics. But the Commodore 64 was unsuiable to Roberta Williams,
presumably because the video chip limited each 8x8 character to 1 foreground
and 1 background color. IBM PC graphics modes are bitmapped, so no similar
restrictions are in place. But successful titles were ported to multiple systems
in those days, and Roberta Williams probably thought of Commodore 64, Apple II,
and Atari ports of King's Quest. She definitely designed the game so that it
would be easily portable to the PC. Since the PC booter version requires 128KB
of RAM and has its own CGA graphics card with a separate 16KB on it, this makes
even more sense.
One interesting idea that Roberta Williams had done was not to use bitmaps to
draw her backgrounds. King's Quest is about 77 screens in size. Each
background takes up about 3/4 of the screen, say 150 lines. Each screen
would be 12KB in size, and 82 screens would be 984KB in size. This is not
counting the sound, interpreter, game code, characters, text, or boot code.
And this game had to fit onto 1 360KB floppy, not 4. Instead of drawing
bitmaps the game engine draws vectors, converting them into bitmaps without
the huge graphic files. However, even though the pictures are small, the Video
Adapter needs to fit the picture into its frame memory. A picture of King's
Quest has up to 16KB of color data.
But as we all know, the IBM PCjr. was a failure. The chicklet keyboard
lacked keys and functionality. The memory was limited and extra added
memory came too little, too late. The memory and video subsystems are
fairly slow. Only one floppy and no hard drive was easily available. The
expansion was proprietary and external. The OS was stored in system ROM,
and could not be replaced easily. It lacked both hardware and software
compatibility with the IBM PC and PC/XT. Too few games were made for the
machine. And it cost over $1,000, making it a very expensive machine for gaming.
So, in 1984 Sierra released King's Quest for the PCjr. But since the PCjr.
is a commercial failure Sierra quickly ports the game to the PC. Along the
same lines the game is later ported to the Tandy 1000, the Commodore Amiga,
the Atari ST, and the Apple //gs. (The releases for the Apple //e and Sega
Master System are quirky) The IBM PC release, on a PC booter, is normally
in 4-color CGA. However, it supports the Color Composite Mode of the CGA
card for 16 colors at 160x200. Although this uses the NTSC color burst and is
not
the sharpest coloring imaginable, it must do for PC owners until Sierra
re-releases King's Quests I and II in 16 color EGA in 1987. By 1986 Sierra
released King's Quest III and Space Quest I for the PC in full 16 color EGA
graphics but stretched the lower resolution until they released the first game
that used their SCI interpreter, King's Quest IV. That 1988 game offered natural
EGA, 16 colors in a true 320x200 resolution. No more blatantly retangular
pixels.
GH
-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 80,000 Newsgroups - 16 Different Servers! =-----
Robert Norton
news:3e8f67e2$3...@corp.newsgroups.com:
> But as we all know, the IBM PCjr. was a failure. The chicklet
> keyboard lacked keys and functionality.
You were going great up to here.
The chicklet keyboard was substituted with an IR (Yes!) keyboard, and
everybody got a free upgrade.
> The memory was limited and
> extra added memory came too little, too late.
The memory could go to 640K with a sidecar, I bought a 512K sidecar from
a 3rd party seller.
> The memory and video
> subsystems are fairly slow. Only one floppy and no hard drive was
> easily available.
I added a second floppy, I modded it in.
> The expansion was proprietary and external. The OS
> was stored in system ROM, and could not be replaced easily.
The BIOS was in 32K of ROM, the OS was on disk. It could be replaced, I
remember how nice DOS 2.1 was; Look, subdirectories!
> It lacked
> both hardware and software compatibility with the IBM PC and PC/XT.
> Too few games were made for the machine. And it cost over $1,000,
> making it a very expensive machine for gaming.
Too few games were made for it.
I bought mine close to the product launch for $700 (which was a lot of
money back then!) although I got in on a good 50% off sale to do that.