diff --git a/delhndlr.s b/delhndlr.s new file mode 100644 index 0000000..249d1ca --- /dev/null +++ b/delhndlr.s @@ -0,0 +1,228 @@ +******************************** +* * +* DELETE KEY HANDLER * +* * +* AUTHOR: BILL CHATFIELD * +* LICENSE: GPL * +* * +******************************** + + ORG $801 + DSK /HD1/SRC/DELHNDLR + +CH EQU $24 ;HORIZ CHAR POS (40-COL) +BASL EQU $28 ;BASE ADDR FOR CURR VIDEO LINE +KSWL EQU $38 ;KEYBOARD SWITCH LOW BYTE +KSWH EQU $39 ;KEYBOARD SWITCH HIGH BYTE +OURCH EQU $57B ;HORIZONTAL POSITION (80-COL) +OURCV EQU $5FB ;VERTICAL POSITION (80-COL) +KBD EQU $C000 ;KEYBOARD DATA + STROBE +KBDSTRB EQU $C010 ;CLEAR KEYBOARD STROBE +CXROMON EQU $C007 ;TURN ON INTERNAL ROM +CXROMOFF EQU $C006 ;ENABLE SLOT ROMS +ALTCHAR EQU $C01E ;>=$80 IF IN 80-COL +COUT EQU $FDED ;WRITE A CHARACTER + +* 80-COL SUBS INSIDE THE INTERNAL ROM +INVERT EQU $CEDD ;INVERT CHAR ON SCREEN +PICK EQU $CF01 ;PICK CHAR OFF SCREEN + +* INPUT SUBS +RDKEY EQU $FD0C +RDCHAR EQU $FD35 +KEYIN EQU $FD1B +BASICIN EQU $C305 +GETLN EQU $FD6A +NOESC EQU $C9B7 ;HANDLES KEY OTHER THAN ESC +BINPUT EQU $C8F6 +ESCAPING EQU $C918 +IN EQU $200 ;256-CHAR INPUT BUFFER + +ESC EQU $9B ;ESC WITH HIGH BIT SET +RTARROW EQU $95 ;RIGHT ARROW WITH HIGH BIT SET +DELETE EQU $FF ;DELETE WITH HIGH BIT SET +BKSPACE EQU $88 ;BACKSPACE WITH HIGH BIT SET + +HEXDEC EQU $ED24 ;HEX-TO-DECIMAL CONVERSION +CROUT EQU $FD8E ;PRINT A CARRIAGE RETURN +STROUT EQU $DB3A ;PRINT NULL-TERM STRING IN AY +* MONITOR SUBS +PRINTXY EQU $F940 ;PRINT X & Y AS HEX +PRBYTE EQU $FDDA ;PRINT BYTE AS 2 HEX DIGITS + +STOR80ON EQU $C001 ;ENABLE AUXILIARY MEM SWITCHING +PAGE2OFF EQU $C054 ;TURN ON MAIN MEMORY +PAGE2ON EQU $C055 ;TURN ON AUXILIARY MEMORY + +DEBUG EQU 1 +DEBUG2 EQU 0 + +******************************** +* * +* PUTS MACRO * +* * +* APPLESOFT MUST BE IN MEMORY * +* BECAUSE THE STROUT SUB IS * +* USED. * +* * +* X & Y ARE PRESERVED * +* * +* ]1 - ADDRESS OF STRING * +* * +******************************** + +PUTS MAC + TYA ;PRESERVE Y + PHA + LDA #<]1 ;PUT LOW BYTE INTO A + LDY #>]1 ;PUT HIGH BYTE INTO Y + JSR STROUT ;CALL APPLESOFT'S STRING PRINT + PLA ;RESTORE Y + TAY + EOM + +******************************** +* * +* PUT80 MACRO * +* * +* IN 80-COL MODE EVEN COLUMNS * +* ARE IN AUXILIARY MEMORY * +* WHILE ODD COLUMNS ARE IN * +* MAIN MEMORY. * +* * +* ]1 - CHARACTER TO DISPLAY * +* ]2 - DESIRED COLUMN * +* * +******************************** + +PUT80 MAC + TYA ;MOVE Y TO A + PHA ;SAVE Y VALUE ON STACK + SEI ;DISABLE INTERRUPTS + STA STOR80ON ;ENABLE MAIN/AUX MEM SWITCHING + LDA ]2 ;LOAD 80-COL HORIZ CURSOR POSITN + LSR A ;DIVIDE BY 2 TO CALC PHYS COLUMN + BCC AUXMEM ;IF EVEN, COLUMN IS IN AUX MEM +MAINMEM STA PAGE2OFF ;TURN OFF AUX MEM, MAIN MEM ON + JMP CONTINUE ;AVOID AUX MEM ENABLE +AUXMEM STA PAGE2ON ;TURN ON AUX MEM, MAIN MEM OFF +CONTINUE TAY ;MOVE CURSOR POSITION TO Y + LDA ]1 ;LOAD THE CHARACTER TO DISPLAY + STA (BASL),Y ;DISPLAY THE CHARACTER + STA PAGE2OFF ;TURN MAIN MEM BACK ON + CLI ;ENABLE INTERRUPTS + PLA ;PULL Y VALUE FROM STACK + TAY ;RESTORE Y VALUE + EOM + +******************************** +* * +* INSTALL VECTOR TO HANDLER * +* * +******************************** + +MAIN + LDA #DELHNDLR + STA KSWH + PUTS LOADMSG + RTS + +******************************** +* * +* KEYBOARD INPUT ROUTINE * +* * +* PRECONDITIONS: * +* 1. CURSOR AT CH & BASL * +* 2. ACCUM = ORIG SCREEN BYTE * +* 3. Y = VALUE IN CH * +* * +* POSTCONDITIONS: * +* 1. MUST RETURN CHAR IN ACCUM * +* 2. X & Y MUST NOT BE CHANGED * +* * +******************************** + +DELHNDLR + STA ORIGCURS ;STORE THE ORIGINAL CURSOR CHAR + TXA ;SAVE X + PHA + TYA ;SAVE Y + PHA + + BIT ALTCHAR ;TEST FOR 80-COL ON + BMI COL80 + +COL40 + JSR GETKEY ;LOAD "KEY" VARIABLE + JSR DEL2BS ;CONVERT DELETE TO BACKSPACE + LDA ORIGCURS + STA (BASL),Y ;REMOVE CURSOR + JMP FINISH + +COL80 + PUT80 #' ';OURCH ;DISPLAY OUR CURSOR, INVERSE SPC + +NEXTKEY + JSR GETKEY ;LOAD "KEY" VARIABLE + JSR DEL2BS ;CONVERT DELETE TO BACKSPACE + CMP #ESC ;IS IT ESC? + BEQ NEXTKEY ;IGNORE ESC + CMP #RTARROW ;IS IT A RIGHT ARROW + BNE CLRCURS ;NOT RIGHT ARROW THEN DONE + LDY OURCH ;GET HORIZONTAL CURSOR POSITION + JSR PICK ;GRAB CHAR FROM SCREEN + ORA #$80 ;SET HIGH BIT + STA KEY + +CLRCURS + PUT80 #" ";OURCH ;ERASE CURSOR + +FINISH + PLA ;RESTORE Y + TAY + PLA ;RESTORE X + TAX + LDA KEY ;LOAD RETURN VALUE + RTS + +******************************** +* * +* GETKEY SUBROUTINE * +* * +******************************** + +GETKEY + BIT KBD ;TEST FOR KEY PRESSED + BPL GETKEY ;WAIT FOR KEY PRESSED + LDA KBD ;GET THE KEY THAT WAS PRESSED + BIT KBDSTRB ;CLEAR KEYBOARD STROBE + STA KEY ;STORE THE KEY THAT WAS READ + RTS + +******************************** +* * +* DEL2BS SUBROUTINE * +* * +******************************** + +DEL2BS + CMP #DELETE ;IS THE KEY IN A THE DELETE KEY + BNE D2BDONE + LDA #BKSPACE + STA KEY +D2BDONE + RTS + +******************************** +* * +* DATA * +* * +******************************** + +LOADMSG ASC "LOADED DELETE HANDLER",0D,00 +KEY DB 0 +ORIGCURS DB 0 + +