2 ! **********************************************************************
3 ! Program          CRTCDEMO.BAS     Utg}va  1.0      1986-11-23
4 ! av Curt Rehnborg, <1121>
5 ! Ins{nd av Curt Rehnborg
6 ! OBS: Det saknas s{tt att avbryta den sk{rmmanipuleringsl{get som
7 ! kommer sist i programmet, annat {n CTRL-C. Du riskerar ocks} att
8 ! l{mna sk{rmen i oanv{ndbart skick. Resetta d} datorn.
10 ! **********************************************************************
11 INTEGER : EXTEND 
12 ; CHR$(12)
20 ; : ; "           DETTA PROGRAM KOMMER ATT F\RKLARA CRTC-KRETSENS FUNKTION."
30 ; "          ==========================================================="
60 FOR T=1 TO 5000 : NEXT T 
70 ! 
80 ; CHR$(12) : K=8
90 ; CUR(3,K) "CRTC {r den krets som styr video och synkgenerering."
100 ; CUR(4,K) "===================================================="
110 ; CUR(7,K) "     Kretsen {r programmerbar f|r exempelvis :"
120 ; CUR(9,K) "               * Antal tecken /rad"
130 ; CUR(10,K) "               * Antal rader /bild"
140 ; CUR(11,K) "               * Vertikal o horisentell frekvens"
150 ; CUR(12,K) "               * Mark|radressering"
160 ; CUR(14,K) "Kretsen genererar ocks} adresser f|r avs|kning av"
170 ; CUR(15,K) "bildminne, linjeadresser f|r teckengenerator."
180 ; CUR(16,K) "Vidare finns en ing}ng f|r ljuspenna.(light pen)"
190 ; CUR(18,K) "Kretsen har beteckningen 6845 och finns i ABC 800/M,802,806."
200 ; CUR(19,K) "Programmeringen av kretsen g|rs vid uppstart eller reset av systemet."
210 ; CUR(20,K) "Antal register som programmeras {r 16 st (R0 - R15)."
220 ; CUR(21,K) "Programmeringen kan {ven utf|ras fr}n Basic."
230 ; CUR(23,54) "(G} vidare tryck tangent)"; : GET \$
240 ! 
250 ; CHR$(12) : K=15
260 ; CUR(4,22) "PROGRAMMERING FR]N BASIC."
270 ; CUR(5,22) "-------------------------"
280 ; CUR(7,K) "CRTC-kretsen behandlas som en intern I/O-enhet"
290 ; CUR(8,K) "och har adresserna  49, 56 och 57."
300 ; CUR(10,K) "Med instruktionen OUT 56,R adresserar man ett"
310 ; CUR(11,K) "av de 18 registren. (R = vilket register)"
320 ; CUR(13,K) "Med OUT 57,D skrivs sedan data till registret"
330 ; CUR(14,K) "                    (D = vilken data)"
340 ; CUR(16,K) "INP (49) l{ser adresserat register"
350 ; CUR(17,K-9) "_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ "
360 ; CUR(19,K-8) "Exempel:    OUT 56,8    (Adresserar register 8)"
370 ; CUR(20,K) "    OUT 57,3    (Data = 3 skrivs in i adresserat register)"
380 ; CUR(21,K) "                (Vilket medf|r interlace-mode)"
390 ; CUR(23,5) "Vill du testa exemplet = (T), G} vidare = (CR)"; : GET T$
400 IF T$="T" OR T$="t" GOTO 420
410 GOTO 440
420 OUT 56,8 : OUT 57,3 : FOR T=1 TO 7000 : NEXT T : OUT 57,0 : GOTO 390
430 ! 
440 ; CHR$(12)
450 H$="HORISONTAL" : V$="VERTIKAL" : I$="INTERLACE mode" : M$="Max Line Adress"
460 C$="CURSOR" : A$="Adress" : T$="Total" : D$="Display" : S$="Sync"
470 R=3 : K=8 : R2=3
480 ; CUR(0,25) "CRTC-KRETSENS REGISTER:"
490 ; CUR(2,K) "Reg nr    Reg namn                     Normalv{rde   L{s  Skriv"
500 ; CUR(R,K) A CUR(R,K+10) H$ CUR(R,K+21) T$ CUR(R,55) "127"
510 A=A+1 : R=R+1
520 ; CUR(R,K) A CUR(R,K+10) H$ CUR(R,K+21) D$ CUR(R,55) " 80"
530 A=A+1 : R=R+1
540 ; CUR(R,K) A CUR(R,K+10) H$ CUR(R,K+21) "Sync delay" CUR(R,55) "100"
550 A=A+1 : R=R+1
560 ; CUR(R,K) A CUR(R,K+10) H$ CUR(R,K+21) "Sync width" CUR(R,55) "  9"
570 A=A+1 : R=R+1
580 ; CUR(R,K) A CUR(R,K+10) V$ CUR(R,K+21) T$ CUR(R,55) " 30"
590 A=A+1 : R=R+1
600 ; CUR(R,K) A CUR(R,K+10) V$ CUR(R,K+21) "adjust" CUR(R,55) "  4"
610 A=A+1 : R=R+1
620 ; CUR(R,K) A CUR(R,K+10) V$ CUR(R,K+21) D$ CUR(R,55) " 24"
630 A=A+1 : R=R+1
640 ; CUR(R,K) A CUR(R,K+10) V$ CUR(R,K+21) "Synk pos" CUR(R,55) " 28"
650 A=A+1 : R=R+1
660 ; CUR(R,K) A CUR(R,K+10) "INTERLACE  mode" CUR(R,55) "  0"
670 A=A+1 : R=R+1
680 ; CUR(R,K) A CUR(R,K+10) "Max Line Adress" CUR(R,55) "  9"
690 A=A+1 : R=R+1
700 ; CUR(R,K) A CUR(R,K+10) C$ CUR(R,K+18) "Start in line" CUR(R,55) " 40"
710 A=A+1 : R=R+1
720 ; CUR(R,K) A CUR(R,K+10) C$ CUR(R,K+18) "End in line" CUR(R,55) "  9"
730 A=A+1 : R=R+1 : R1=R
740 ; CUR(R,K) A CUR(R,K+10) "Start adress VDU mem (H)" CUR(R,55) "120"
750 A=A+1 : R=R+1
760 ; CUR(R,K) A CUR(R,K+10) "Start adress VDU mem (L)" CUR(R,55) "  0"
770 A=A+1 : R=R+1
780 ; CUR(R,K) A CUR(R,K+10) C$ CUR(R,K+18) "Adress (H)" CUR(R,55) "120"
790 A=A+1 : R=R+1
800 ; CUR(R,K) A CUR(R,K+10) C$ CUR(R,K+18) "Adress (L)" CUR(R,55) "  0"
810 A=A+1 : R=R+1
820 ; CUR(R,K) A CUR(R,K+10) "Light Pen reg (H) read only" CUR(R,55) "---"
830 A=A+1 : R=R+1
840 ; CUR(R,K) A CUR(R,K+10) "Light Pen reg (L) read only" CUR(R,55) "---"
850 R=5 : K=63
860 FOR L=1 TO 6
870   ; CUR(R1,K) "X"
880 R1=R1+1 : NEXT L 
890 K=68
900 FOR L=1 TO 16
910   ; CUR(R2,K) "X"
920 R2=R2+1 : NEXT L 
930 ON ERROR GOTO 1000
940 ; CUR(22,10);"Vilket register vill du skriva data i"; : INPUT R
950 ; CUR(22,10);"                                                ";
960 ; CUR(22,10);"Data till register " R " = "; : INPUT D
970 ; CUR(22,10);"                                                     ";
980 OUT 56,R : OUT 57,D
990 GOTO 960
1000 IF R=0 THEN U=127
1001 IF R=1 THEN U=80
1002 IF R=2 THEN U=100
1003 IF R=3 THEN U=9
1004 IF R=4 THEN U=30
1005 IF R=5 THEN U=4
1006 IF R=6 THEN U=24
1007 IF R=7 THEN U=28
1008 IF R=8 THEN U=0
1009 IF R=9 THEN U=9
1010 IF R=10 THEN U=40
1011 IF R=11 THEN U=9
1012 IF R=12 THEN U=120
1013 IF R=13 THEN U=0
1014 IF R=14 THEN U=120
1015 IF R=15 THEN U=0
10000 OUT 56,R : OUT 57,U : GOTO 930