SKETCH.BAS

Please find reproduced here a working port of SKETCH for the TRS Model 100 to Stefan’s BASIC for the Arduino micro-controller platform.

Full code listing:

https://basiclang.solarpunk.au/d/15-sketchbas

Please find the archive.org link to the 1984 book here:

https://archive.org/details/25GamesForYourTrs80Model100/page/n49/mode/1up

Live Coding Session

CODE LISTING

10 REM ***********
20 REM *         *
30 REM * Sketch  *
40 REM *         *
50 REM ***********
   
55 REM *** Instructions ***
   
60 CLS:PRINT:PRINT
70 PRINT TAB(12)"Instructions?"
80 PRINT:PRINT TAB(16)"(Y/N)"
90 GET A$:IF A$="" GOTO 90
100 IF A$="Y" OR A$="y" THEN GOTO 110 ELSE GOTO 270
110 CLS:PRINT:PRINT
120 PRINT TAB(2)"You may use either Sketch or Draft"
130 PRINT TAB(2)"modes. Sketch uses a moving line to"
140 PRINT TAB(2)"draw, while Draft draws lines between"
150 PRINT TAB(2)"two points you specify by hitting ";CHR$(34);"S";CHR$(34);"."
160 PRINT:PRINT TAB(1)"= Hit any key for Sketch instructions =";
170 GET A$:IF A$="" GOTO 170
180 CLS:PRINT
190 PRINT TAB(12)"==  Sketch =="
200 PRINT TAB(13)"[Controls:]"
210 PRINT TAB(2)"Arrow Keys -- Change direction"
220 PRINT TAB(2)"Number keys -- Slow down cursor"
230 PRINT TAB(2)CHR$(34);"F";CHR$(34);" -- Return to top speed"
240 PRINT TAB(2)"Space Bar -- Toggle cursor (ON)-(OFF)"
250 PRINT:PRINT TAB(11)"== Hit any key =="
260 GET A$:IF A$="" GOTO 260
    
265 REM *** Set Delay ***
    
270 CLS:PRINT:PRINT
280 PRINT TAB(6)"Enter speed desired:"
290 PRINT
300 PRINT TAB(6)"[1] Fast to [9] Slow"
310 GET A$:IF A$="" GOTO 310
320 OG=VAL(A$)*10:IF OG<1 GOTO 310
330 DL=OG
    
335 REM ***  Choose Sketch or Draw Mode ***
    
340 CLS:PRINT:PRINT
350 PRINT TAB(4)"Do you want:"
360 PRINT:PRINT TAB(6)"[S]ketch mode"
370 PRINT TAB(6)"[D]raft mode"
380 GET A$:IF A$="" GOTO 380
390 IF A$="S" OR A$="s" GOTO 420
400 IF A$="D" OR A$="d" GOTO 710
410 GOTO 380
420 CLS
430 REM FOR N=1 TO VAL(RIGHT$(TIME$,2))
440 REM DM=RND(1)
450 REM NEXT N
460 X=239:Y=63
470 X1=INT(RND(X)*X)+1:Y1=INT(RND(X)*Y)+1
480 COLOR 255: PLOT X1,Y1
    
485 REM *** Sketch Mode ***
    
490 GET A$
500 X1=X1+XD:IF X1>239 THEN X1=239
510 IF X1<0 THEN X1=0
520 Y1=Y1+YD:IF Y1>63 THEN Y1=63
530 IF Y1<0 THEN Y1=0
540 DELAY DL*10
550 IF FLAG<>1 GOTO 570
560 COLOR 255:PLOT X1,Y1:DELAY 100:NEXT N:COLOR 0:PLOT X1,Y1:GOTO 580
570 COLOR 255:PLOT X1,Y1
580 IF A$="" GOTO 490
590 IF VAL(A$)<1 GOTO 610
600 DL=DL*VAL(A$)
610 IF A$="F" OR A$="f" THEN DL=OG
620 A=ASC(A$)
630 IF A<>32 GOTO 650
640 IF FLAG=1 THEN FLAG=0 ELSE FLAG=1
    
650 IF A=4 GOTO 670
651 IF A=5 GOTO 690
652 IF A=19 GOTO 680
653 IF A=24 GOTO 700
654 GOTO 490
    
655 REM *** Change direction of Cursor ***
    
660 REM ON A-27 GOTO 670, 680, 690, 700
670 YD=0:XD=1:GOTO 490 REM RIGHT
680 YD=0:XD=-1:GOTO 490 REM LEFT
690 XD=0:YD=-1:GOTO 490 REM UP
700 YD=1:XD=0:GOTO 490 REM DOWN
    
705 REM *** Draft  Mode ***
    
710 X1=40:Y1=40
720 CLS
730 GET A$
740 X1=X1+XD:IF X1>239 THEN X1=239
750 IF X1<0 THEN X1=0
760 Y1=Y1+YD:IF Y1>63 THEN Y1=63
770 IF Y1<0 THEN Y1=0
780 DELAY DL*10
790 COLOR 255:PLOT X1,Y1
800 DELAY 50
810 COLOR 0:PLOT X1,Y1
820 IF A$="" GOTO 730
830 IF A$="S" or A$="s" GOTO 850
840 GOTO 990
    
845 REM *** Set one point ***
    
850 PO=PO+1
860 COLOR 255:PLOT X1,Y1
870 IF PO=1 THEN X2=X1:Y2=Y1:GOTO 730
    
875 REM ***  Draw Line ***
    
880 LINE X1,Y1,X2,Y2
890 PO=0
900 GET A$:IF A$="" GOTO 900
910 IF A$="S" OR A$="s" GOTO 950
920 A=ASC(A$)
930 IF A<>4 AND A<>5 AND A<>19 AND A<>24 GOTO 900
940 GOTO 980
950 PO=1
960 X2=X1:Y2=Y1
970 GOTO 900
    
975 REM *** Change Cursor Direction ***
980 IF A=4 GOTO 990 REM RIGHT
981 IF A=5 GOTO 1010 REM UP
982 IF A=19 GOTO 1000 REM LEFT
983 IF A=24 GOTO 1020 REM DOWN
984 GOTO 900
990 YD=0:XD=1:GOTO 730
1000 YD=0:XD=-1:GOTO 730
1010 XD=0:YD=-1:GOTO 730
1020 YD=1:XD=0:GOTO 730