Classic Computer Magazine Archive COMPUTE! ISSUE 67 / DECEMBER 1985 / PAGE 124


Modifications or Corrections To Previous Articles

Atari Witching Hour

Goblins apparently invaded our lister program while this Halloween game from the October issue (p. 54) was printing. The mysterious { = } character in lines 1310 and 1320 should instead be the vertical line character, SHIFT-= .


The Commodore 64, Atari, and TI versions of this astronomy plotting program from the November issue (p. 62) do not work properly for latitudes between the equator and 24 degrees south. Trying to plot a skyscape for a location in this area—Peru or northern Australia, for example—results in an ILLEGAL QUANTITY ERROR message or a misplaced sun. In the Commodore 64 version (Program 1), the culprit is the second ABS in line 2510. The line should read as follows:

2510 IF ABS (LL) < 24 THEN LB = 40 * INT (LL/7 + .5)

The correction is the same for the Atari version (Program 2), except that the line number is 2540. For the TI version (Program 5), make the change to line 2440.

All About IBM Batch Files

The {CTRL-P} character which appears in Programs 2, 3, and 4 of this overview of batch files is not correct. Wherever this character appears, you should instead type whatever key or key combination produces an ESCape character, CHR$(27). If you use the EDLIN text editor from the IBM PC-DOS system disk, the proper replacement is {CTRL-V}[. That is, hold down the CTRL key and type V, then release CTRL and V and type [. Note that the left bracket ([) is in addition to any brackets that are already in the listing. For example, with EDLIN the first line of Program 3 would be typed as follows:

{CTRL-V} [[2J {CTRL-V} [[32m

Other text editors or word processors may require another combination. Check the manual for the editor you are using to see what you need to type to produce ASCII character 27.

There is also a correction for the last paragraph in the article (p. 88). The statement shown as:


should read:

IF .= = %1. GOTO : NOPARAM

64 Color Plotter

There are no errors in this graphics utility program from the "64 Multicolor Graphics Made Easy" article in the October issue (p. 90). However, there was one point that the article failed to make completely clear: Programs with "Color Plotter" commands work only if they are typed in while Color Plotter is active. If you type in a program containing Color Plotter commands—for example, Program 2 from the article—in regular BASIC, then activate Color Plotter, the program appears correct when you list it, but will not run. Instead, all Color Plotter commands will cause syntax errors. You can convert the faulty program statements to true Color Plotter statements by activating Color Plotter, listing the problem line on the screen, moving the cursor to that line, and pressing RETURN. Always be sure that Color Plotter is active before typing in any programs using its special commands. And remember that you have to reactivate Color Plotter each time you press RUN/STOP-RESTORE.