Classic Computer Magazine Archive COMPUTE! ISSUE 50 / JULY 1984 / PAGE 153


Modifications Or Corrections To Previous Articles

Atari Snertle

Program 3 (p. 94) of this math tutorial from the May issue has a bug in its subtraction routine. In those cases when the answer to the displayed problem should be zero, a zero will not be accepted as the correct result. Donald Carlson points out that line 362 should read as follows:

362 IF Q=2 AND K<=L THEN M=L-K

64 Hi-Res Graphics Editor

The notes to this program (May issue, p. 82) failed to state the required starting and ending addresses to use when typing the MLX portion of the editor (Program 2). The values are 49152 for the start and 51553 for the end. Also, the series of steps required to set up the program may seem cumbersome. Andy Van Duyne has provided this short program, which will perform all the steps for you:

10 IF FL=0 THEN FL = 1 : LOAD"HIRES/ML",8, 1
20 PRINT"{CLR}{2 DOWN}POKE642,128 : POKE44,
      128 : POKE32768,0 : NEW"
50 POKE 198,6 : POKE 631,13 : POKE 632,13 : POK
      E 633,13
60 POKE 634,82 : POKE 635,213 : POKE 636,13

The program assumes you have used the filenames HIRES/ML for the machine language portion (typed in with MLX) and HIRES/BAS for the BASIC portion (Program 3). Change these names in lines 10 and 30 to match the names you used. To use the program with tape, change the 8 to a 1 in lines 10 and 30. You must have the BASIC portion saved on the tape immediately following the machine language portion.

The screen dump feature of the editor will not work with the new Commodore 1526 printer, since this model does not have the dot-addressable graphics feature of the Commodore 1525 printer.