Sunday, January 22, 2012
99 ways to program a hex, Part 14: COLOR COMPUTER BASIC
Yesterday's code was labeled “COLOR COMPUTER BASIC, EASY” not because it was easy to write (it was somewhat easy—seeing how I didn't have to run it, and going off referenece material for a language I haven't used in over twenty years) but because it was relatively “easy” to read.
I'm being serious.
I never saw any published BASIC code look that nice. No, it would usually be presented as this (but probably without the blank lines):
1 '*****************************
2 '* COPYRIGHT 2012 SEAN CONNER
3 '*
4 '* THIS PROGRAM RELEASED UNDER
5 '* THE GNU LICENSE, VERSION 2
6 '* OF THE LICENSE, OR (AT YOUR
7 '* OPTION) ANY LATER VERSION.
8 '*
9 '* SEE THE GNU GENERAL PUBLIC
10 '* LICENCE FOR MORE DETAILS.
11 '***************************
12 '
13 'COLOR COMPUTER BASIC
14 'REQUIRES EXTENDED AND
15 'DOS BASIC TO RUN.
16'
20 PRINT "INPUT FILE NAME:";:INP
UT FN$:OPEN"I",#1,FN$:I=0:Y=0:FO
R S=1TOLOC(2):GET#1,S:D$=INPUT#1
:FOR B=1TO256STEP8:DD$=MID$(D$,B
,16):I$=HEX$(I):IF LEN(I$)<>4 TH
EN I$ = MID$("000",1,4-LEN(I$))+
I$
21 H$="":A$="":FOR C=1TO8:B$=MID
$(H$,C,1):IF CHR$(B$)<32 OR CHR$
(B$)>1THEN B$="."
22 A$=A$+B$:T$=HEX$(B$):IF LEN(T
$)=1THENT$="0"+T$
23 H$=H$+T$:NEXT C:PRINTI$;": ";
H$;" ";A$:I=I+8:Y=Y+1:IF Y=15 TH
EN INPUT T$:Y=1
24 NEXT B:NEXT S:CLOSE#1:END
Line 20 here covers lines 20 through 103 of yesterday's code, and I only broke it there because of the IF statement, which ends at the end of a number statement. Otherwise, it could have been longer, up to 255 characters in length. All due to memory constraints—4,096 bytes, 16,384 bytes or 32,768 bytes of RAM to fit both the program and data (and if you want high resolution graphics, you give up 6,144 bytes; 12,288 bytes if you want double-buffered high resolution graphics—and by “high resolution graphics” I mean 256×192 pixels, two colors).
Yes kids, this is how we used to write programs. And part of the reason why BASIC has the terrible reputation that it does.
