╘WO CHARACTER TABLES ARE IN USE. ╘O CHANGE TO THE OTHER TABLE HOLD THE SHIFT KEY DOWN WHILE PRESSING THE ├= KEY. ╧NE OF THESE TABLES, THE ONE YOU GET AFTER SWITCHING ON THE COMPUTER, DOES NOT INCLUDE LOWER CASE LETTERS, BUT HAS GRAPHIC CHARACTERS INSTEAD, WHILE THE OTHER TABLE HAS BOTH UPPER CASE AND LOWER CASE LETTERS, WITH FEWER GRAPHIC CHARACTERS.
╘HE COLOUR OF TEXT (FOREGROUND COLOUR) ON THE SCREEN CAN BE CHANGED, WITH 16 COLOURS AVAILABLE. ╘HEY ARE BLACK, WHITE, RED, CYAN, PURPLE, GREEN, BLUE, YELLOW, ORANGE, BROWN, LIGHT RED, DARK GRAY, MEDIUM GRAY, LIGHT GREEN, LIGHT BLUE AND LIGHT GRAY.
╘O START A DIFFERENT TEXT COLOUR ON THE SCREEN HOLD DOWN THE CONTROL KEY, OR, FOR A DIFFERENT SET OF COLOURS, THE ├= KEY, AND PRESS ONE OF THE KEYS LABELLED 1 TO 8.
╒SING A ┬┴╙╔├ PROGRAM TO SEE WHICH COLOUR NUMBER YIELDS WHICH COLOUR, TYPE THIS PROGRAM. ╬OTE THAT THE LINE NUMBERS ARE OPTIONAL, AS LONG AS THEY ARE IN INCREASING ORDER, AND SPACES ALSO ARE OPTIONAL; THEY MAKE THE PROGRAM EASIER TO READ WHEN LISTED. ╘O LIST IT TYPE LIST OR L╔ (LOWER CASE EL AND UPPER CASE I).
456INPUT " COLOUR NUMBER (0 - 15 ONLY)";I: POKE 646,I
458?"THIS COLOUR IS NO."I: GO TO 456
╘YPE THIS PROGRAM IN, WITH RETURN AFTER EACH LINE. ╘O START IT TYPE RUN, AND TO STOP IT HOLD THE RUN/STOP KEY DOWN WHILE PRESSING THE RESTORE KEY.
╘O CHANGE MEMORY LOCATION 646, USING MACHINE LANGUAGE (M/L), DIVIDE 646 BY 256 AND FIND THE REMAINDER; THIS GIVES US 2 AND 134. ┴SSUMING WE WANT TO CHANGE THE COLOUR TO ╬O.1 USING THE MACHINE LANGUAGE, WE FIRST LOAD THE ACCUMULATOR (.┴) WITH 1 (169 1), AND THEN STORE THE CONTENT OF .┴ IN 646 (141 134 2). ╚ERE IS, FOR EXAMPLE, A ┬┴╙╔├ PROGRAM TO STORE THESE NUMBERS IN MEMORY. ╘HIS PART OF MEMORY (╥┴═) IS FOR USE WITH TAPE CASSETTE STORAGE; ╔ USE ONLY DISKS, MAKING THIS PART OF ╥┴═ AVAILABLE FOR MACHINE LANGUAGE PROGRAMS:
100FOR I=820 TO 1023: READ A: IF A > 256 THEN SYS820:END
102POKE I,A: NEXT
104DATA 169,1, 141,134,2, 96, 999
╚ERE IS A ┬┴╙╔├ PROGRAM THAT LETS YOU SELECT A SPECIFIC SPOT ON THE SCREEN, AND PUTS A CHARACTER THERE, IN THE COLOUR OF YOUR CHOICE; HOWEVER THERE MAY BE TWO DIFFERENT RESULTS FOR A GIVEN SCREEN CHARACTER NUMBER, DEPENDING ON WHICH OF THE CHARACTER TABLES IS IN USE.
10 INPUT "LOCATION (1024-2023, 999=END)";A:IFA=999 THEN END
20 INPUT "CHARACTER NUMBER (0-255)";B
30 INPUT "COLOUR NUMBER (0-15)";C
40 POKE A,B
50 POKE A+54272,C
60 GOTO 10
╘O SEE WHICH CHARACTERS ARE AVAILABLE ON THE SCREEN, TYPE IN THIS PROGRAM, RETURN, CLEAR THE SCREEN BY HOLDING DOWN THE SHIFT KEY WHILE PRESSING THE CLR/HOME KEY, AND THEN TYPE RUN TO GET THE PROGRAM STARTED:
10 FOR I=0 TO 255: POKE 1184+I,I: NEXT: END
╬OTE THAT 128 TO 255 ARE NEARLY THE SAME AS 0 TO 127, EXCEPT THAT THE CHARACTERS ARE "REVERSED"; THE FOREGROUND COLOUR AND BACKGROUND COLOUR ARE EXCHANGED. ┴LSO KEEP SWITCHING THE TWO CHARACTER TABLES (╙HIFT/├=) TO SEE WHAT EACH TABLE PROVIDES FOR ALL OF THE SCREEN DISPLAY CODES (0-255).
╙CREEN CODE NUMBERS ARE NOT THE SAME AS M/L NUMBERS, WHICH ARE USED FAR MORE OFTEN THAN SCREEN CODES. ╨RINT STATEMENTS OFTEN INCLUDE CHARACTER STRING NUMBERS; FOR EXAMPLE CHR$(158) IN A PRINT STATEMENT WILL SWITCH TO YELLOW. ╘HE M/L NUMBERS FOR THE COLOURS ARE:
BLACK(144), WHITE(5), RED(28), CYAN(159), PURPLE(156), GREEN(30), BLUE(31), YELLOW(158), ORANGE(129), BROWN(149), LIGHT RED(150), DARK GRAY(151), MEDIUM GRAY(152), LIGHT GREEN(153), LIGHT BLUE(154), AND LIGHT GRAY(155).
╘O SEE THE RESULTS OF SUCH PRINT STATEMENTS USE THIS ┬┴╙╔├ PROGRAM, NOTING AGAIN THAT THERE ARE TWO TABLES (CHANGE BY SHIFT/├=) OF CHARACTERS:
10 FOR I=33 TO 129:?CHR$(I);:NEXT
20 FOR I=149 TO 255:?CHR$(I);:NEXT
╚ERE IS A SLOW-MOTION ┬┴╙╔├ PROGRAM TO SHOW THE RESULTS OF USING M/L NUMBERS:
10 FORA=33 TO 255:?A;CHR$(A)
20 FORB=1 TO 3000: NEXT B
30 NEXT A: END
╘O TYPE TEXT ON SCREEN USING PRINT STATEMENTS IN THE ┬┴╙╔├ LANGUAGE, USE QUOTATIONS. ╒SE ONLY UP TO 80 CHARACTERS, INCLUDING LINE NUMBERS (2 LINES), BUT IF YOU PUT A SEMICOLON AT THE END AFTER THE END QUOTE, RETURN, THEN THE NEXT LINE WILL CONTINUE. ╞OR EXAMPLE:
╙TRING VARIABLES, SUCH AS IT$, ARE USED TOO, THEY ARE DEFINED LIKE THIS, FOR EXAMPLE, FOR USE LATER AS ?IT$:
10 IT$="IT IS NOT GOING TO RAIN TODAY."
╘YPING INTO MEMORY DIRECTLY VIA POKE STATEMENTS OF THE ┬┴╙╔├ LANGUAGE CAN ALSO BE DONE. ╔ USUALLY DO NOT START BELOW MEMORY LOCATION 20000 BECAUSE THE ┬┴╙╔├ LANGUAGE MAY POSSIBLY NEED THE MEMORY SPACE BELOW THAT. ╫RITING INTO ┬┴╙╔├ SPACE IS NOT RECOMMENDED, AS IT MAY RESULT IN LOTS OF TROUBLE, INCLUDING THE LOSS OF COMMUNICATIONS WITH THE COMPUTER. ╔F THAT HAPPENS SWITCHING OFF THE COMPUTER WILL RESET THINGS TO NORMAL, EXCEPT THAT ALL WORK DONE THAT HAS NOT BEEN SAVED ON DISK OR TAPE HAS TO BE REPEATED.
10 INPUT "╙TART WHERE IN MEMORY (20000+)";M: M=M-1: ?" ^=END"
12 GET A$:IFA$="" THEN 12
14 IFA$=" " THEN ?M:END
16 A=ASC(A$): M=M+1: POKE M,A:?A$;:GOTO 12
╘O READ THE M/L NUMBERS ON SCREEN THAT ARE IN MEMORY, HERE IS A ┬┴╙╔├ PROGRAM TO DO THAT:
10INPUT" ╙TART, END WHERE IN MEMORY";S,E
12FOR I=S TO E: ?ST╥(P┼(I));:N┼: END
╘O SLOW DOWN PRINTING ON SCREEN HOLD DOWN THE CONTROL KEY DURING PRINTING. ╘O STOP IT PRESS THE RUN/STOP KEY. ╨RINTING CAN BE RESUMED BY TYPING CONT FOLLOWED BY PRESSING THE RETURN KEY.
