Modifications Or Corrections To Previous Articles
Machine Language: Factors
The commands to prepare the computer to enter Program 2, the VIC and 64 version of the machine language factoring routine from the January "Machine Language" column (p. 178), should read:
POKE 4608, 0 : POKE 44, 18 : NEW
Commodore Files For Beginners, Part 3
On page 193 of the January issue, lines 340, 350, and 360 should have a semicolon (;) following the CHR$(13).
Disk Explorer For Commodore
This program from the December 1983 issue (p. 298) requires the following corrections, supplied by reader Duane Martin?
160 INPUT A$ : IF LEFT$(A$,1) = "$" THEN 190 1100 GETC? : IFCS = "" THEN1040
Line 190 of this machine language editor from the December issue (p. 216) creates a count of data blocks for use in the boot process. However, the line as written may cause problems due to rounding of the block count value when partial blocks are involved. Don Klich suggests the following change to avoid this problem:
190 BEG = BEG-24 : BUFFER$ = CHR$(0) : BUFFER$(2) =CHR$(INT((FIN - BEG + 127)/128))
This should not be a factor in getting the "Chopperoids" program to operate correctly. See the February issue for the corrections to Chopperoids.
Comparing Commodore Machine Language Programs
Readers attempting to run this utility from the December 1983 issue (p. 340) on the Commodore 64 should note that lines 240 and 350 contain PET 4.0 BASIC disk status variables which are not supported by the 64's BASIC. In addition to the changes noted in the article, the following are also required:
225 OPEN 15, 8, 15 240 INPUT#15, DS, DS$, D1, D2 : IF DS<> 0 THEN PRINT DS$ : STOP 350 INPUT#15, DS, DS$, D1, D2 : IF DS<>0 THEN PRINT DS$ : STOP
Overseas readers may be interested to learn that the built-in time-of-day clock in the 64's CIA chip can be adjusted for their 50 Hz household current with a simple POKE. C. J. Ayers of Guildford, Surrey, England, notes that adding the line:
75 POKE 56334, 129
to the program from the December issue (p. 344) will cause it to keep proper time on European 64s.
Termulator For The 64
Line 170 of Program 2 of this article from the November 1983 issue (p. 222) should read:
170 DATA 133, 106, 32, 189, 255, 169, 192
The value 3515 in line 120 will need to be changed to 3485 to reflect the change to the DATA. With this correction, Program 2 will create a tape copy of the data loaded by Program 1 without a filename. To reload "Termulator" from the tape created by Program 2, type:
LOAD "",1, 1
Thanks to Stan Lefkowitz for pointing out this correction.