256 Color Display By Jerry Burianyk Bally BASIC: CURSOR 2, no. 5 (January/February 1981): 86-87. AstroBASIC: AstroBASIC Manual, page 94 Machine Language Manager: MLM manual, page 7-5.
This is video art for Bally Arcade/Astrocade with Bally BASIC or "AstroBASIC."
Display all 256 colors of the Astrocade's palette on the screen at the same time.
This program doesn't exactly match a strict definition for video art, but it shows more than the eight colors that the Astrocade is normally capable of showing from a cartridge and more than the four colors that BallyBASIC/AstroBASIC can normally show using a BASIC program. While there are no on-screen patterns, it took some thought and a sort-of technical artist to write this program that seems to push the Astrocade beyond its technical limitations.
This video is broken into several parts, to make viewing it easier for those interested in only certain portions of this video history.
0:00 - 256 Color Display, Overview of Program 6:27 - 256 Color Display, Program Loading and Running (Capture Card) 7:38 - 256 Color Display, Program Loading and Running (Canon Powershot SX60) 11:06 - 256 Color Display, BASIC Listing 11:51 - End Credits
From the AstroBASIC manual:
"This program has especially delighted the average user as it appears to be impossible to accomplish such a thing with Bally BASIC. You will find out how good your television is as this program will push its color displaying capabilities to the limit! Thanks to The Basic Express newsletter for sharing this program with us."
Though the text doesn't mention this, try moving the paddle of hand controller number one for a neat affect.
Program Description from Cursor:
Display All 256 Colors on Screen at One Time By Jerry Burianyk CURSOR 2, no. 5 (January/February 1981): 86-87.
This program uses the PEEK command (%(Location)=Value) to store a machine language program in the "Tape Input Buffer." The program was first written in Z80 machine language (MNEMONIC), then converted to hex (OPCODE). The HEX was translated to decimal and subsequently POKED into memory locations 20200 (4EED) through 20260 (4F24).
We strongly suggest the use of The Cursor Group "PEEK N' POKE" manual to fully understand this procedure. The "PEEK N' POKE" manual is a beginner level instruction course.
The 256 color program uses Screen Interrupts which Brett Bilbrey so brilliantly pioneered with his "CRITTER" program in the October 1980 issue of CURSOR.
The width of the 256 color display is governed by the value of &(9) in line 330. The interrupts allow concurrent processing. Once you are running this program, you can press "HALT", the Color program will continue running and you can eliminate lines 10 through 400 by keying in the line number and "GO" (remember-the BASIC program is only used to assemble a machine language program in the "Tape Input Buffer"),the BASIC program is no longer needed.
To stop the Color program, key-in ":RETURN". If you have eliminated lines 10- 400, restart program by keying "CALL 20200".
The quantity of colors displayed can be limited by using Hand Control Knob #1.
This program will give your TV it's supreme test of quality. We use a 10 inch Panasonic with our Bally in the office, and it is capable of only showing about 14 colors. Our Zenith, however, showed them all!!
Many, many thanks to Jerry & Brett for sharing their results with us!