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Assembly Source File | 1987-12-11 | 72.8 KB | 3,325 lines

TITLE KEYBOARD BUFFER PAGE 60, 132 ;********************************************************************** ;* Keyboard Buffer and Editor VERSION 2.0 ;* ;* This program provides two independent functions: ;* 1) it extends the DOS_keyboard_buffer to 128 characters and ;* 2) it provides command-line storage and editing facilities ;* ;* Source: self contained 8088/8086 Macro Assembler Language ;* Script: MASM KBEDIT; ;* LINK KBEDIT; ;* EXE2BIN KBEDIT.EXE KBEDIT.SYS ;* ;* Usage: install as a device driver by including a statement ;* in the CONFIG.SYS file of the form: ;* ;* DEVICE=KBEDIT.SYS [B:nnn] [C:nnn] [K:nnn] [/A] [/N] ;* ;* B:nnn is buffer size for stored strings in bytes ;* (default = 512) ;* C:nnn is maximum number of strings in the string buffer ;* (default = 32) ;* K:nnn is keyboard buffer size in characters ;* (default = 128) ;* ;********************************************************************** JMPS MACRO LABEL JMP SHORT LABEL ENDM CLR MACRO REG SUB REG, REG ENDM GET_CHAR MACRO ;----- return keyboard input in AL through DOS-call ; MOV AH, 8 ;; function number INT 21H ENDM ; -----DOS-keyboard pointers ; DOS_DATA_AREA SEGMENT AT 40H ORG 17H DOS_KB_FLAG DB ? ORG 1AH KB_HEAD DW ? KB_TAIL DW ? ORG 71H DOS_BREAK_FLAG DW ? ORG 80H DOS_BUFFER_START DW ? DOS_BUFFER_END DW ? DOS_DATA_AREA ENDS ;----- interrupt_vector_adresses_equates ; KB_INTERRUPT EQU 4*9H KB_IO_ROUTINE EQU 4*16H DOS_FUNCTION_INT EQU 4*21H ;----- equates ; NULL EQU 00H CR EQU 0DH LF EQU 0AH BACKSPACE EQU 08H ESCAPE EQU 1BH CTRL_U EQU 15H CTRL_W EQU 17H EOF EQU 1AH ACK EQU 06H TAB EQU 09H OFF EQU 0 ON EQU NOT OFF NOT_INST EQU 0AAH ; ;----- ; the following keys are identified by extended ascii-codes ; the second byte is given in these equates ; INSERT EQU 052H DELETE EQU 053H CURSOR_LEFT EQU 04BH CURSOR_RIGHT EQU 04DH PREV_LINE EQU 048H ; = cursor up NEXT_LINE EQU 050H ; = cursor down CURSOR_BEGIN EQU 047H ; = home key CURSOR_END EQU 04FH ; = end key F1 EQU 03BH F2 EQU 03CH F3 EQU 03DH F4 EQU 03EH F5 EQU 03FH F6 EQU 040H F7 EQU 041H CTRL_LEFT EQU 073H CTRL_RIGHT EQU 074H CTRL_HOME EQU 077H CTRL_END EQU 075H CTRL_PGUP EQU 084H CTRL_PGDN EQU 076H SHIFT_F5 EQU 058H SHIFT_F6 EQU 059H ALT_1 EQU 078H ALT_2 EQU 079H ALT_3 EQU 07AH ALT_4 EQU 07BH ALT_5 EQU 07CH ALT_6 EQU 07DH ALT_7 EQU 07EH ALT_8 EQU 07FH ALT_9 EQU 080H ALT_0 EQU 081H CODE SEGMENT PUBLIC ASSUME CS:CODE START_CODE = $ HEADER DD -1 ; device_driver obligatory ; first four bytes ATTRIBUTE DW 8000H ; attribute byte: DW D_STRATEGY DW D_INTERRUPT DRVNAME DB 'KBEDT ' ;----- installation messages ; MSG_VERSION DB 'Keyboard Buffer and Command Line Editor,' DB ' Version 2.0', CR, LF, LF, NULL DB ' author: P. Kranenburg' DB ' University of Leiden, The Netherlands' ;----- keyboard related messages ; MSG_KB_1 DB ' Keyboard buffer size : ', NULL MSG_KB_2 DB ' characters', CR, LF, NULL MSG_KB_NO_1 DB ' KeyBoard Buffer size ', NULL MSG_KB_NO_2 DB ' is too small: not installed', CR, LF, NULL MSG_KB_IN DB ' KeyBoard Buffer Installed' DB CR, LF, NULL MSG_KB_UN DB ' KeyBoard Buffer Uninstalled' DB CR, LF, NULL MSG_KB_PR DB ' Keyboard Buffer already installed' DB CR, LF, NULL MSG_KB_NOT_PR DB ' Keyboard Buffer was not active' DB CR, LF, NULL ;----- editor related messages ; MSG_EDT_1 DB ' Command line buffer size : ', NULL MSG_EDT_2 DB ' bytes', CR, LF DB ' Number of commands in buffer : ', NULL MSG_EDT_3 DB ' ', CR, LF, LF, NULL MSG_EDT_IN DB ' Command Line Editor Installed' DB CR, LF, NULL MSG_EDT_UN DB ' Command Line Editor Uninstalled' DB CR, LF, NULL MSG_EDT_PR DB ' Command Line Editor already installed' DB CR, LF, NULL MSG_EDT_NOT_PR DB ' Command Line Editor was not active' DB CR, LF, NULL ;----- pointers to request_header ; REQ_HEADER_OFS DW ? REQ_HEADER_SEG DW ? ;----- control data sent to output-routine of driver ; EXPECTSECOND DB OFF ; first/second byte indicator FIRSTPART DB LOW ON ; first byte of incoming control codes KB_INST DB OFF ; keyboard buffer presence flag EDT_INST DB NOT_INST; keyboard editor presence flag BIOS_TTY_SW DB LOW ON ; true on driver initialization TEN DW 10 ; operand for MULtiply operation ;----- local stack for processing buffered input function call ; LOCAL_STACK DW 256 DUP(?) ;----- containers for user stack-segment and -pointer ; CALLERS_STACK_SEGMENT DW ? CALLERS_STACK_POINTER DW ? RET_FROM_STACK_ROUTINES DW ? ; temp var for SETSTACK and RESETSTACK ;----- routines to switch stacks ; SETSTACK PROC NEAR POP RET_FROM_STACK_ROUTINES ; save return address MOV CALLERS_STACK_SEGMENT, SS ; now save user stack MOV CALLERS_STACK_POINTER, SP ; PUSH CS POP SS ; install new stack MOV SP, OFFSET LOCAL_STACK + SIZE LOCAL_STACK JMP RET_FROM_STACK_ROUTINES ; return SETSTACK ENDP RESETSTACK PROC NEAR POP RET_FROM_STACK_ROUTINES PUSH CALLERS_STACK_SEGMENT POP SS ; restore stack registers MOV SP, CALLERS_STACK_POINTER ; JMP RET_FROM_STACK_ROUTINES RESETSTACK ENDP ;----- enlarged keyboard buffer ; KBBUFFER_SIZE DW 256 KBBUFFER DW ? ;----- containers for old interrupt_vector_adresses ; OLD_KEYB_IO DD ? OLD_KEYB_INT DD ? OLD_FUNCTION_INT DD ? OLD_DOS_BUFFER_START DW ? OLD_DOS_BUFFER_END DW ? ;#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-# ;# ;# *** Description of data-structure used in Editor-routines *** ;# ;# Quantities Assignments ;# ;# ;# - actice/inactive switch - - - EDT_INST ;# ;# Buffer data: ;# ;# - current character pointer in buffer - - - register DI ;# - current number of characters in buffer - - - register BL ;# - current number of characters up to but - - - register BH ;# not including the current cursor ;# - maximum number of characters in buffer - - - register DL ;# exclusive final Carriage Return ;# - insert/overwrite mode - - - INSERT_TOGGLE ;# ;# Display data: ;# ;# - screen coordinates of start displayed string- - - STR_START_POS ;# - screen coordinates of end displayed string - - - STR_END_POS ;# - current video page - - - VIDEO_PAGE ;# - current cursor position on the screen - - - CURSOR_POS ;# - cursor shape - - - CURSOR_TYPE ;# - current screen width - - - MAX_COL ;# - number of character rows - - - MAX_ROW (fixed:25) ;# ;# - full/partial editing capability - - - FULL_EDIT ;# - defer-mode when redirected input/output - - - DEFER_DSPL ;# - cursor positioning through ANSI-escape codes- - - ANSI ;# ;# ;# ;# Lay-out of the buffer passed through DS:DX ;# ;# ;# +----------+----------+-------+--/ /--+---------+-------+--/ /--+--------+ ;# | BufLen | #chars | D(1) | ... |D(#chars)| 'CR' | ... | N+3 | ;# | = N | in buf | | | | | | | ;# +----------+----------+-------+--/ /--+---------+-------+--/ /--+--------+ ;# ;# at offset 0: length of buffer (exclusive first two bytes and final CR) ;# 1: length of actual number of characters in buffer ;# (exclusive final CR) ;# 2 .. [byte(1)]+1 : data ;# [byte(2)]+2 : 'Carriage Return' ;# ;# ;# The buffer can contain a string on input as well. This is checked for at ;# entrance ( a carriage return must be present at the byte ;# with index: [byte(2)]+2 ) ;# If present the input string is inserted in the string buffer to make it ;# available for editing. ;# ;# ;#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-# INSERT_TOGGLE DB OFF DEFER_DSPL DB OFF FULL_EDIT DB OFF CURSOR_TYPE DW ? ; cursor-status on entry CURSOR_MASK EQU 00011111B ; mask for set cursor INSERT_SHIFT DB 4 ; determines cursor-shape ; change in INSERT-mode CURSOR_POS LABEL WORD CURSOR_COL DB ? CURSOR_ROW DB ? STR_START_POS LABEL WORD STR_START_COL DB ? STR_START_ROW DB ? STR_END_POS LABEL WORD STR_END_COL DB ? STR_END_ROW DB ? MAX_ROW EQU 25 MAX_COL DB 80 ; assumed default for display-width VIDEO_PAGE DB 0 ANSI DB OFF ANSI_GET_CURSOR DB ESCAPE, '[6n', NULL DEVICE_PROLOGUE PROC NEAR ;**************************************************************** ;* Find out about devices attached to standard input and ouput by ;* issuing a IOCTL (044H) function call. ;* ;* If either STDIN or STDOUT is attached to a file then writing ;* characters to STDOUT is deferred until editing is complete. ;* ;* If STDOUT is NOT the Console Output then direct cursor ;* manipulation is disabled, i.e. when a multiple line string, ;* the cursor position on the screen does not reflect the current ;* position in the string. ;* ;* STDIN EQU 0 STDOUT EQU 1 ISDEV EQU 0080H ISCOT EQU 0002H PUSH DX PUSH BX ;----- initialize variables ; MOV DEFER_DSPL, ON MOV FULL_EDIT, OFF; MOV STR_START_POS, 0 MOV STR_END_POS, 0 MOV CURSOR_POS, 0 ;----- check standard input ; MOV BX, STDIN ; BX is handle MOV AX, 4400H ; AL = 0: get device information INT 21H ; status returned in DX TEST DX, ISDEV JZ DP_LX ; if bit off then file ; else device ;----- check standard output ; MOV BX, STDOUT ; BX is handle MOV AX, 4400H ; AL = 0: get device information INT 21H ; status returned in DX TEST DX, ISDEV JZ DP_LX ; bit not set: file MOV DEFER_DSPL, OFF ; TEST DX, ISCOT JZ DP_LX CMP ANSI, ON ; ANSI or BIOS cursor handling ? JE DP_L1 ;----- get video state ; MOV AH, 0FH INT 10H MOV MAX_COL, AH MOV VIDEO_PAGE, BH ;----- get cursor position and attributes ; MOV AH, 03 ; BH still contains video page number INT 10H ; get current cursor MOV CURSOR_TYPE, CX ; save cursor data JMPS DP_L2 DP_L1: LEA SI, ANSI_GET_CURSOR ; get cursor position through CALL PRINT ; ANSI-sequence <esc>[6n CALL ANSI_REPLY ; get ANSI-reply DP_L2: MOV CURSOR_POS, DX ; initialize cursor variables MOV STR_START_POS, DX ; MOV STR_END_POS, DX ; MOV FULL_EDIT, ON ; DP_LX: POP BX POP DX RET DEVICE_PROLOGUE ENDP DEVICE_EPILOGUE PROC NEAR ;----------------------------------------------------- ; in: SI = pointer to start of string ; If DEFER_DSPL is ON then now is the time to display ; the completed current string. ; A final carriage return is sent to standard output ; in all cases. ; MOV INSERT_TOGGLE, OFF CALL SET_CURSOR_TYPE CMP DEFER_DSPL, ON MOV DEFER_DSPL, OFF ; tell DISPLAY_COMPLEX to no longer ; postpone display JNE DE_L2 ;----- must send string to STDOUT now CLR CH MOV CL, [SI-1] ; load length of string JCXZ DE_L2 CLD DE_L1: LODSB CALL DISPLAY_COMPLEX LOOP DE_L1 DE_L2: MOV AL, CR CALL DISPLAY_CHAR RET DEVICE_EPILOGUE ENDP SET_CURSOR_POS PROC NEAR ;----------------------------------------------- ; If FULL_EDIT is ON then the cursor position ; on the screen is updated according to the value ; in CURSOR_POS. ; If ANSI is ON then cursor-positioning is done ; through ANSI-escape-sequences, else through ; BIOS video-routines. ; PUSH DX PUSH BX PUSH AX CMP FULL_EDIT, ON JNE SCP_LX MOV DX, CURSOR_POS CMP ANSI, ON JE SCP_L1 ;----- cursor positioning through BIOS ; function no. 2, DX = cursor-pos ; MOV BH, VIDEO_PAGE MOV AH, 2 INT 10H JMPS SCP_LX SCP_L1: ;----- cursor positioning through ANSI ; output ANSI-sequence <esc>[<col>;<row>f ; Note: ANSI row- and column-numbers are ; in the range: 1 .. MaxRow/MaxCol ; MOV AL, ESCAPE CALL WRITE_CHAR ; <esc> MOV AL, '[' CALL WRITE_CHAR ; [ MOV AL, DH ; print row number INC AL CLR AH ; CALL PRINT_NUM ; MOV AL, ';' ; ; CALL WRITE_CHAR MOV AL, DL ; print column number INC AL CLR AH ; CALL PRINT_NUM ; MOV AL, 'f' ; f CALL WRITE_CHAR SCP_LX: POP AX POP BX POP DX RET SET_CURSOR_POS ENDP SET_CURSOR_TYPE PROC NEAR ;---------------------------------------------------------------- ; Set cursor shape to value in variable CURSOR_TYPE. ; This can only be done through BIOS-VIDEO call so ; full edit mode must be ON and ANSI mode OFF ; CMP FULL_EDIT, ON JNE SCT_L2 CMP ANSI, OFF ; no cursor type change JNE SCT_L2 ; if ANSI on PUSH CX PUSH AX MOV CX, CURSOR_TYPE ; set proper cursor type CMP INSERT_TOGGLE, ON JNE SCT_L1 ; if insert-state SUB CH, INSERT_SHIFT ; make larger cursor SCT_L1: AND CH, CURSOR_MASK MOV AH, 01 INT 10H POP AX POP CX SCT_L2: RET SET_CURSOR_TYPE ENDP ANSI_REPLY PROC NEAR ;------------------------------- ; get reply from ANSI-driver ; must be of the form <esc>[#;#R<cr> ; out: DX=#;# ; PUSH CX PUSH BX GET_CHAR ; CMP AL, ESCAPE ; <esc> ? JNE AR_LX GET_CHAR CMP AL, '[' ; [ JNE AR_LX MOV BL, ';' ; get first # (row) CLR CX AR_L1: ; CX = intermediate number GET_CHAR CMP AL, BL ; JE AR_L3 ; CMP AL, '9' ; read number and convert JA AR_LX ; SUB AL, '0' ; JB AR_LX ; XCHG CX, AX PUSH DX MUL TEN POP DX JNC AR_L2 ; test for overflow OR AX, TEN ; do something to reset Z-flag JMPS AR_LX AR_L2: CLR CH ; add new digit ADD AX, CX XCHG CX, AX JMP AR_L1 AR_L3: DEC CL ; 1 .. Max --> 0 .. Max-1 CMP BL, 'R' ; read second # (column) JE AR_L4 MOV DH, CL MOV BL, 'R' CLR CX JMP AR_L1 AR_L4: MOV DL, CL AR_LX: GET_CHAR ; wait for Carriage Return CMP AL, CR ; JNE AR_LX ; POP BX POP CX RET ANSI_REPLY ENDP SECOND_CODE_TABLE LABEL BYTE ;----- table of extended ascii-codes ; DB INSERT DB DELETE DB CURSOR_LEFT DB CURSOR_RIGHT DB PREV_LINE DB NEXT_LINE DB CURSOR_BEGIN DB CURSOR_END DB F1 DB F2 DB F3 DB F4 DB F5 DB F6 DB F7 DB CTRL_LEFT DB CTRL_RIGHT DB CTRL_HOME DB CTRL_END DB CTRL_PGUP DB CTRL_PGDN DB SHIFT_F5 DB SHIFT_F6 DB ALT_1 DB ALT_2 DB ALT_3 DB ALT_4 DB ALT_5 DB ALT_6 DB ALT_7 DB ALT_8 DB ALT_9 DB ALT_0 DB 00 ; end of table CODE_TABLE_LENGTH = $ - OFFSET SECOND_CODE_TABLE ;----- ECJT = Extended Code Jump Table ; ECJT LABEL WORD DW MAIN_LOOP_RETURN DW ALT_DIGIT ; get old string DW ALT_DIGIT DW ALT_DIGIT DW ALT_DIGIT DW ALT_DIGIT DW ALT_DIGIT DW ALT_DIGIT DW ALT_DIGIT DW ALT_DIGIT DW ALT_DIGIT DW SHIFT_F6_R ; cursor shape control DW SHIFT_F5_R ; for INSERT-mode DW CTRL_PGDN_R ; cursor-bottom up DW CTRL_PGUP_R ; cursor-top up DW CTRL_END_R ; cursor-bottom down DW CTRL_HOME_R ; cursor-top down DW CTRL_RIGHT_R ; cursor up DW CTRL_LEFT_R ; cursor down DW F7_R ; zero-byte in string DW F6_R ; control-Z in string DW F5_R ; add string to buffer DW F4_R ; erase from begin to cursor DW F3_R ; erase from cursor to end DW F2_R ; word right DW F1_R ; word left DW CURSOR_END_R DW CURSOR_BEGIN_R DW NEXT_LINE_R DW PREV_LINE_R DW CURSOR_RIGHT_R DW CURSOR_LEFT_R DW DELETE_R DW INSERT_R PAGE ;#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#- ;# ;# *** Data structure to maintain a buffer of previous strings *** ;# ;# ;# ___/------ STR_BUF_START ;# C_TBL_START ------\ _________ |_x_| ;# |_________| |_x_| ;# |_________| |_x_| ;# |_________| |_x_| ;# C_TBL_HEAD ------>|_________|-------\ |_x_| ;# |_________|----\ \ |_x_| ;# |_________| \ \-------> |_x_| ;# |_________| \ |_y | ;# |_________| \ |_y | ;# C_TBL_TAIL ------>|_________|-- \ \ |_y_| ;# |_________| \ \ |_y_| ;# |_________| \ \ |_y | ;# C_TBL_END ---------/ \ \-----> |_y_| ;# \ ~ ~ ;# C-table \ ~_ _~ ;# \ |_z_| ;# \ |_z_| ;# \ |_z_| ;# \----> |_z_| ;# |___| ;# |___| ;# |___| ;# \------- STR_BUF_END ;# ;# string-buffer ;# ;# ;# The entries in C_TABLE point to the last character of a string ;# in STR_BUF. ;# ;# C_TBL_HEAD points to the entry in C-table which identifies the oldest ;# string in the string-buffer. ;# ;# C_TBL_TAIL points to the entry in C-table which points to the last ;# byte of free space in the string-buffer. ;# ;#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#-#- STR_BUF_SIZE DW 512 ; default string-buffer ; size is 512 STR_BUF_START DW ? STR_BUF_END DW ? ;----- pointers to mark begin and end of data in the string buffer ; STR_BUF_HEAD DW ? STR_BUF_TAIL DW ? ;----- table of pointers to strings in string buffer ; ; pointers in string pointer table to locate ; the string currently being processed ; ; C_TBL_HEAD identifies the oldest string in STR_BUF ; C_TBL_TAIL points to the last free byte in STR_BUF, i.e. the byte ; before the begin of the string pointed to by C_TBL_HEAD ; C_TBL_SIZE DW 60 ; default 30 commands C_TBL_START DW ? C_TBL_END DW ? C_TBL_HEAD DW ? C_TBL_TAIL DW ? CURRENT DW ? ; identifies the string current- ; ly being edited ;************************************************************ ; Next are a couple of routines to handle pointer- ; updating for the cyclic buffers defined above. ; Pointers are passed in the BX register ; BX is advanced to the next or previous table-item. ;************************************************************ SCROLLUP_TBL PROC NEAR CMP BX, C_TBL_START ; at start of table? JNE SUT_L1 ; no: then go update pointer MOV BX, C_TBL_END ; yes: scroll to end of ; table first SUT_L1: DEC BX ; DEC BX ; pointer to previous entry RET SCROLLUP_TBL ENDP SCROLLDO_TBL PROC NEAR INC BX ; pointer to next entry INC BX ; CMP BX, C_TBL_END ; past end? JNE SDT_L1 ; no: all is well MOV BX, C_TBL_START ; yes: back to start of table SDT_L1: RET SCROLLDO_TBL ENDP BEEP PROC NEAR ;---------------------------------------------- ; Buffer full/error beep ; PUSH CX PUSH AX MOV AL, 10010110B ; select Timer 2, low order Count OUT 43H, AL CLR AL ; set low order Count JMP $+2 ; allow for AT pecularities OUT 42H, AL ; (slow 8053-chip) MOV AL, 10100110B ; select Timer 2, high order Count OUT 43H, AL MOV AL, 3 ; pitch JMP $+2 OUT 42H, AL ; set high order Count IN AL, 61H MOV AH, AL ; save value OR AL, 03H ; turn speaker on JMP $+2 OUT 61H, AL MOV CX, 20000 ; beep length BRRR: LOOP BRRR MOV AL, AH ; restore old value OUT 61H, AL POP AX POP CX RET BEEP ENDP WRITE_CHAR PROC NEAR ;------------------------------------------ ; Display character in AL via OS call 2 ; or through BIOS TTY routine 0EH ; (necessary at initialization) ; PUSH AX CMP BIOS_TTY_SW, ON JNE W_CH_L1 MOV AH, 0EH ; TTY-command INT 10H ; video-BIOS-routine JMPS W_CH_LX W_CH_L1: PUSH DX MOV DL, AL ; deliver in DL MOV AH, 2 ; function number INT 21H POP DX W_CH_LX: POP AX RET WRITE_CHAR ENDP PRINT PROC NEAR ;------------------------------------------------------------- ; This routine displays a string a string of characters on ; the crt-screen. ; The string is assumed to start at address DS:SI ; and must end with a null byte. ; CLD PRINT_L1: LODS BYTE PTR CS:[SI] OR AL, AL ; load bytes until JZ PRINT_L2 ; a zero is read CALL WRITE_CHAR JMP PRINT_L1 PRINT_L2: RET PRINT ENDP PRINT_NUM PROC NEAR ;--------------------------------------- ; Convert to ascii and display number ; in: AX: unsigned integer ; ; PUSH DX PUSH CX PUSH BX MOV BX, 10 ; BX = divisor CLR CX ; CX = digit count PR_N_L1: CLR DX ; DX:AX = dividend DIV BX PUSH DX ; remainder on stack INC CX ; keep count OR AX, AX ; quotient = 0 ? JNE PR_N_L1 ; if not, compute next digit PR_N_L2: POP AX ; get digits from stack ADD AL, '0' ; convert to ascii CALL WRITE_CHAR ; and display LOOP PR_N_L2 ; POP BX POP CX POP DX RET PRINT_NUM ENDP PAGE DISPLAY_CHAR PROC NEAR ;--------------------------------------------------------------- ; Display character in AL. ; Update cursor data. ; CALL WRITE_CHAR CMP AL, CR JNE DCH_L1 ;----- carriage return ; MOV CURSOR_COL, 0 RET DCH_L1: CMP AL, LF JNE DCH_L3 ;----- line feed ; CMP CURSOR_ROW, MAX_ROW - 1 JE DCH_L2 INC CURSOR_ROW DCH_L2: RET DCH_L3: CMP AL, BACKSPACE JNE DCH_L5 ;----- backspace ; DEC CURSOR_COL ; cursor one left JNS DCH_L4 ; if < 0 MOV AL, MAX_COL ; wrap back to previous row ADD CURSOR_COL, AL ; DEC CURSOR_ROW CALL SET_CURSOR_POS ; must set cursor explicitly DCH_L4: ; for wrap back RET DCH_L5: ;----- other characters ; MOV AX, STR_END_POS ; AX := difference between SUB AX, CURSOR_POS ; STR_END and CURRENT PUSH AX INC CURSOR_COL MOV AL, MAX_COL ; increment column count CMP CURSOR_COL, AL ; if at end move to next line JB DCH_L6 ; MOV CURSOR_COL, 0 ; CMP CURSOR_ROW, MAX_ROW - 1 ; on last row ? JE DCH_L6 ; yes, don't increment ROW INC CURSOR_ROW ; because of scrolling DCH_L6: POP AX OR AX, AX ; update STR_END_POS JNZ DCH_L7 ; if necessary MOV AX, CURSOR_POS MOV STR_END_POS, AX DCH_L7: RET DISPLAY_CHAR ENDP DISPLAY_COMPLEX PROC NEAR ;************************************************************** ;* This procedure takes an ascii-code looks for control-code ;* and displays it on the screen in the proper format ;* in: AL : ascii-code ;* ;* Irregular service for BS and TAB ;* ;* If DEFER_DSPL is ON then display of the string being edited ;* is deferred until editing is complete. ;*************************************************************** CMP DEFER_DSPL, ON JE DC_X CMP AL, 20H ; is it a control character ? JNB DC_NO_CTRL ; CMP AL, BACKSPACE ; control characters, JE DC_NO_CTRL ; handle BS and TAB different CMP AL, TAB ; JNE DC_L2 ; ;----- display TAB character, ie. display spaces until ; current column number = 0 (MOD 8) ; PUSH CX CLR CH MOV CL, CURSOR_COL ; OR CL, 0F8H ; CL := 8 - (CURSOR_COL MOD 8) NEG CL ; DC_L1: MOV AL, ' ' CALL DISPLAY_CHAR LOOP DC_L1 POP CX JMPS DC_X ;----- display control character other then TAB or BS ; first display a caret, then the corresponding capital ; ie. ascii 1 displays as: '^A' ; DC_L2: PUSH AX MOV AL, '^' ; display ascii-control-character CALL DISPLAY_CHAR POP AX OR AL, 40H ; make it readable DC_NO_CTRL: CALL DISPLAY_CHAR DC_X: RET DISPLAY_COMPLEX ENDP DISPLAY_TAIL PROC NEAR ;************************************************* ;* this routine displays the substring starting ;* at the character pointed to by DI, to the end ;* of the buffer ;* in: CX: number of blanks to display after the ;* string to blank out any remnant characters ;************************************************* PUSH CURSOR_POS ; save current screen position PUSH CX MOV CL, BL ; get length of substring SUB CL, BH ; in CX CLR CH JCXZ DT_L2 ; display specified blanks if ; the substring is empty MOV SI, DI DT_L1: LODSB ; get character to display CALL DISPLAY_COMPLEX LOOP DT_L1 DT_L2: POP CX ; recover number of additional blanks JCXZ DT_L4 DT_L3: MOV AL, ' ' ; CALL DISPLAY_COMPLEX ; LOOP DT_L3 DT_L4: POP CX ; recover screen position MOV AL, CH ; AL := (OLD)STR_END_ROW SUB CX, CURSOR_POS ; NEG CX ; !! CX := CURSOR_POS - (OLD)STR_END_POS SUB AL, CURSOR_ROW NEG AL ; AL := CURSOR_ROW - (OLD)STR_END_ROW MOV AH, MAX_COL ; sofar we pretended each row is 256 NEG AH ; characters long, so now we must MUL AH ; compensate for this by subtracting SUB CX, AX ; (256 - characters/column)*ROW_diff. ; JCXZ DT_L6 DT_L5: MOV AL, BACKSPACE ; use as backspace count CALL DISPLAY_COMPLEX ; move cursor back LOOP DT_L5 DT_L6: RET DISPLAY_TAIL ENDP MOVE_TAIL_LEFT PROC NEAR ;*************************************************** ;* routine to move the substring starting right of ;* the current cursor position, pointed to by DI, ;* one position to the left, overwriting the current ;* cursor position ;* none of the pointers are updated ;*************************************************** PUSH CX PUSH DI CLR CH ; MOV CL, BL ; get length of substring SUB CL, BH ; in CX DEC CX JNA MTL_LX ; test for non-empty substring MOV SI, DI ; INC SI ; SI at first item to move CLD ; count forward REP MOVSB ; MTL_LX: POP DI POP CX RET MOVE_TAIL_LEFT ENDP MOVE_TAIL_RIGHT PROC NEAR ;*************************************************** ;* routine to move the substring starting at ;* the current cursor position, pointed to by DI, ;* one position to the right. ;* none of the pointers are updated ;*************************************************** PUSH CX PUSH DI CLR CH ; MOV CL, BL ; length of substring in CX SUB CL, BH ; JCXZ MTR_LX ; no business for empty string ADD DI, CX ; DI one past end string MOV SI, DI DEC SI ; SI at end string STD ; count backward REP MOVSB ; MTR_LX: POP DI POP CX RET MOVE_TAIL_RIGHT ENDP BACK_TAB PROC NEAR ;************************************************************ ;* Compute number of backspaces needed to remove a TAB ;* at the current cursor position. ;* It is assumed that string pointers are consistent ;* i.e. DI points to position of TAB to be removed ;* and BL, BH give length of whole string and prefix resp. ;* required number = 8 - (current screen colunm MOD 8) ;* ;* out: CL: equivalent number of spaces for TAB in question ;************************************************************ PUSH DI ; save current string index PUSH DX ; save string length DEC DI ; position on previous character CLR CH MOV CL, BH ; CX := prefix length MOV DH, 07H MOV AL, 20H JCXZ BT_3 STD ; scan downwards through prefix BT_1: SCASB JBE BT_2 ; control character ? CMP BYTE PTR ES:[DI+1], TAB ; JE BT_4 ; if tab then exit loop (we certainly are ; at screen position which equals 0 (MOD 8) ) DEC DH BT_2: LOOP BT_1 ; here: CL = length to penultimate tab ; or zero (if no tab) BT_3: ; and: DH = - (no of carets) SUB DH, STR_START_COL ; DH := - carets - STR_START_COL BT_4: SUB DH, BH ; DH := - carets {- STR_START_COL} ; - total ADD CL, DH ; CL := - carets {- STR_START_COL} ; - (length since penultimate tab) AND CL, 07H ; CL := 8 - ((-CL) MOD 8) INC CL ; CLD ; reset direction flag POP DX ; restore string length POP DI ; and string index RET BACK_TAB ENDP PAGE ;-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ; ; K E Y B O A R D E D I T O R ( ENTRY POINT ) ; ;-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* FUNCTION_INT_ENTRY PROC ;**************************************************************** ;* the address of this routine is placed in the interrupt vector ;* to intercept interrupt 21H. Function call 0AH is handled here, ;* others are passed on to DOS ;* ;**************************************************************** CMP EDT_INST, OFF JZ FI_NOT_ACTIVE CMP AH, 0AH JZ FI_ENTRY FI_NOT_ACTIVE: ;----- go on to DOS-routines ; JMP CS: OLD_FUNCTION_INT FI_ENTRY: STI PUSH ES ; PUSH DS ; PUSH BP ; PUSH DI ; PUSH SI ; save registers PUSH DX ; PUSH CX ; PUSH BX ; PUSH AX CALL SETSTACK ; use own stack CALL DEVICE_PROLOGUE MOV AX, DS ; make ES point to buffer- MOV ES, AX ; segment also MOV SI, DX CLD LODSW ; get length of the passed buffer PUSH SI ; save address of start of actual string OR AL, AL ; if length = zero return JZ FI_EXIT MOV DL, AL ; DL will contain the string's DEC DL ; maximum length, without the ; final Carriage Return MOV CL, AH CLR CH MOV BX, CX JCXZ FI_RESTART CMP BYTE PTR DS:[SI+BX], CR ; is input-string ; terminated properly ? JNE FI_RESTART ; no, ignore CALL STR_BUF_INSERT FI_RESTART: MOV DH, STR_START_COL ; initialize column counter MOV CURSOR_COL, DH CALL SET_CURSOR_POS MOV INSERT_TOGGLE, OFF ; overwrite mode CALL SET_CURSOR_TYPE CLR BL ; BL will contain the current number ; of characters in the string CLR BH ; BH will contain the number of ; characters up to but not including ; the cursor position POP DI ; DI is the current position in the ; buffer PUSH DI ; address back on stack GET_CHAR ; get first character CMP AL, LF ; if first character is a JE MAIN_LOOP ; line-feed then throw it away JMP MAIN_ENTRY ; enter main loop at main ; entrance-point FI_EXIT: POP SI CALL DEVICE_EPILOGUE CALL RESETSTACK ; restore user stack POP AX ; POP BX ; POP CX ; POP DX ; POP SI ; restore registers POP DI ; POP BP ; POP DS ; POP ES ; IRET FUNCTION_INT_ENTRY ENDP MAIN_LOOP PROC NEAR GET_CHAR MAIN_ENTRY: CMP AL, ACK JE MAIN_LOOP ; no ACK's LEA BP, MAIN_LOOP ; set up return address on PUSH BP ; the stack for all routines ; wishing to return to MAIN_LOOP CMP AL, LF JE LF_RN ; CMP AL, BACKSPACE ; find out whether one JE BACKSPACE_RN ; of these special ; CMP AL, ESCAPE ; characters was read ; JE ESCAPE_RN ; CMP AL, CTRL_U JE ESCAPE_RN CMP AL, CR ; search for editing JE CR_R ; keys CMP AL, CTRL_W JE CW_RN CMP AL, 0 ; JE EXTENDED_ASCIIN ; ;----- a character must be inserted in the current string ; M_L1: CMP INSERT_TOGGLE, ON ; insert- or JNE OVERWRITE ; overwrite-mode? CMP BL, DL ; is buffer full ? JB M_L2 ; no: put this character CALL BEEP ; in the buffer RET ; else: ring the bell M_L2: CALL MOVE_TAIL_RIGHT ; make room for new character CLD ; STOSB ; insert the new character INC BL ; update length INC BH ; and cursor position CLR CX ;---- display updated string ; also postlude for OVERWRITE routine ; M_L3: CALL DISPLAY_COMPLEX ; display the new character CALL DISPLAY_TAIL ; and those to the right of it M_L4: RET OVERWRITE: CMP BH, BL ; if cursor position JB M_L6 ; at end, then check for CMP BL, DL ; full buffer JB M_L5 ; CALL BEEP ; RET ; M_L5: ; INC BL M_L6: ; if a character is added at INC BH ; the end, update total ; length also CLR CX CMP BH, BL ; at end of string ? JE M_L8 ; yes, just add it ;----- must overwrite some character ; get character to overwrite in AH ; character to overwrite with still in AL MOV AH, ES:[DI] CMP AH, TAB ; is it a TAB ? JNE M_L7 ; go if not ;----- get rid of TAB ; PUSH AX DEC BH ; BACKTAB expects string CALL BACK_TAB ; pointers set up for tab prefix INC BH ; restore prefix length DEC CX POP AX JMPS M_L8 M_L7: CMP AH, 20H ; if control character JAE M_L8 ; then check character to write INC CX CMP AL, TAB ; tab can also show as one space JE M_L8 CMP AL, 20H JNB M_L8 ; if not cntr-char DEC CX ; display extra space ;----- character to buffer ; M_L8: CLD STOSB JMP M_L3 ; go update screen ;----- boost some conditional jumps ; LF_RN: JMP LF_R BACKSPACE_RN: JMP BACKSPACE_R ESCAPE_RN: JMP ESCAPE_R CW_RN: JMP CTRL_W_R EXTENDED_ASCIIN:JMP EXTENDED_ASCII CR_R: ;---------------------------- ; add a Carriage Return to the end of the string, set string-length byte ; insert in STR_BUF, and go to exit ; ! the carriage return character is sent to STDOUT in DEVICE_EPILOGUE ; CLR CH ; MOV CL, BL ; set DI to end of string SUB CL, BH ; ADD DI, CX ; STOSB ; and put carriage return there PUSH STR_END_POS POP CURSOR_POS CALL SET_CURSOR_POS POP BP ; remove return address from stack POP SI ; recover first-byte address PUSH SI LEA BP, FI_EXIT PUSH BP MOV [SI-1], BL ; store count CLR CH MOV CL, BL ; length in CX STR_BUF_INSERT: ;----------------------------------------------------- ; On entry CX contains the length of the string ; and SI points to the string's first byte. ; note: this code is called as a subroutine at entry ; and by F5_R ; When freeing space to insert a new string, as many of ; the oldest strings are removed as is necessary to make ; room for the new one. Because maximum string length is ; is 255 and minimum length of strings in the buffer is 1 ; it follows that no more than 255 should ever be removed. ; Therefore, a counter is maintained during the the loop ; which removes old strings from the buffer to prevent an ; accidentally corrupted data-structure from causing an ; endless loop here. ; JCXZ SBI_L17 ; if string-length = 0 don't insert ;----- load register DI with address of last byte before ; begin of free space in STR_BUF ; MOV BX, C_TBL_TAIL ; MOV CURRENT, BX ; must update CURRENT CMP BX, C_TBL_HEAD JE SBI_L1 CALL SCROLLUP_TBL SBI_L1: MOV DI, CS:[BX] JE SBI_L18 ; if table empty, we should not enter ; compare routine ; ! proc SCROLLUP does not set Z-flag ;----- determine whether string is different from previous ; PUSH DI MOV AX, DI CMP BX, C_TBL_HEAD ; wrap pointers if appropriate JNE SBI_L11 ; MOV BX, C_TBL_TAIL ; JMPS SBI_L12 SBI_L11: CALL SCROLLUP_TBL SBI_L12: MOV DI, CS:[BX] SUB AX, DI ; compute length of previous string JAE SBI_L13 ; ADD AX, STR_BUF_SIZE; string can wrap in STR_BUF SBI_L13: CMP AX, CX ; compare lengths JNE SBI_L16 ; go if not equal PUSH ES ; save registers altered PUSH SI ; when comparing strings PUSH CX ; MOV AX, CS ; set up addressing MOV ES, AX ; CLD ; INC DI ; SBI_L14: CMP DI, STR_BUF_END ; compare string in JNE SBI_L15 ; STR_BUF with input string MOV DI, STR_BUF_START ; ; SBI_L15: ; CMPSB ; LOOPZ SBI_L14 ; POP CX ; restore registers POP SI ; POP ES ; SBI_L16: POP DI JNE SBI_L18 SBI_L17: RET ; return if strings proved equal SBI_L18: ;----- next get an entry in C_TBL for the new string ; MOV BX, C_TBL_TAIL ; C_TBL_TAIL is moved to make room, MOV AX, CS:[BX] ; save its contents first, ... PUSH DI ; ADD DI, CX ; calculate where new string CMP DI, STR_BUF_END ; will end in STR_BUF, JB SBI_L2 ; SUB DI, STR_BUF_SIZE SBI_L2: MOV CS:[BX], DI ; ... then fill it with new length POP DI CLR DH ; use as retry count for loop ; starting at label SBI_L3 CALL SCROLLDO_TBL ; MOV C_TBL_TAIL, BX ; new tail MOV CURRENT, BX ; and new current also CMP BX, C_TBL_HEAD ; collision with head ? JNE SBI_L3 ; no, go and restore contents PUSH BX ; yes, remove oldest string CALL SCROLLDO_TBL ; space is automatically deallocated MOV C_TBL_HEAD, BX ; by moving the pointers POP BX ; BX back at tail MOV AX, CS:[BX] ; new value for end of free space SBI_L3: MOV CS:[BX], AX ; set new C_TBL_TAIL to current ; end of free space ;----- determine if there is enough free space to hold the new ; string and keep removing old entries until there is ; SUB AX, DI ; AX contains current end of free space JA SBI_L4 ; AX=DI means STR_BUF is empty (free- ; pointer = last-string-pointer) ADD AX, STR_BUF_SIZE; undo wrap-around effect SBI_L4: CMP AX, CX ; is there enough ? JA SBI_L5 ; yes, go and do the transfer ; note: always keep one byte free DEC DH ; how many times did we try ? JZ SBI_ERR ; if zero too many: something is wrong ; exit with beep, also RESET is called PUSH BX ; no, remove another entry from TABLE MOV BX, C_TBL_HEAD MOV AX, CS:[BX] ; get address of last byte occupied CALL SCROLLDO_TBL ; by this entry's string MOV C_TBL_HEAD, BX ; new head of the table POP BX ; JMP SBI_L3 ; try again ;----- now we are ready for the transfer ; SBI_L5: MOV AX, CS ; MOV ES, AX ; set up target pointers INC DI ; CLD ; count in right direction SBI_L6: CMP DI, STR_BUF_END ; JNE SBI_L7 ; wrap-around if neccesary MOV DI, STR_BUF_START SBI_L7: MOVSB ; store bytes of string LOOP SBI_L6 ; until done (CX=0) MOV AX, DS ; MOV ES, AX ; restore ES SBI_LX: RET SBI_ERR: CALL RESET_EDT CALL BEEP RET LF_R: CALL CURSOR_END_R MOV AL, LF CALL DISPLAY_CHAR MOV AL, CR CALL DISPLAY_CHAR RET BACKSPACE_R: OR BH, BH ; is cursor at begin of string ? JZ BS_L1 ; yes, then nothing to do CALL CURSOR_LEFT_R ; otherwise, delete the character CALL DELETE_R ; left of the current cursor-position BS_L1: RET ;--------------------------------- ; abandon current string and start editing a new one ESCAPE_R: CALL CURSOR_BEGIN_R CALL F4_R CALL CURSOR_END_R ADD SP, 2 ; discard return address on stack JMP FI_RESTART ; redo from scratch ; Delete previous whitespace, or alphanumerics CTRL_W_R: CALL BACKSPACE_R ; delete a character in any case OR BH, BH ; at beginning of string? JZ CW_RET ; yes, done CMP BYTE PTR [DI-1],' ' ; tab or... JZ CTRL_W_BL CMP BYTE PTR [DI-1],' ' ; blank or... JZ CTRL_W_BL CTRL_W_LOOP: CMP BYTE PTR [DI-1],'0' ; numeric JB CW_RET CMP BYTE PTR [DI-1],'9' ; ... JBE CTRL_W_NB CMP BYTE PTR [DI-1],'A' ; or alpha, continue deletion JB CW_RET CMP BYTE PTR [DI-1],'Z' JBE CTRL_W_NB CMP BYTE PTR [DI-1],'a' JB CW_RET CMP BYTE PTR [DI-1],'z' JBE CTRL_W_NB CW_RET: RET CTRL_W_BL: CALL BACKSPACE_R ; Flush previous character OR BH,BH ; at beginning? JZ CW_RET ; Yes... CMP BYTE PTR [DI-1],' ' ; tab or... JZ CTRL_W_BL CMP BYTE PTR [DI-1],' ' ; blank or... JZ CTRL_W_BL JMP CW_RET CTRL_W_NB: CALL BACKSPACE_R ; delete a character in any case OR BH, BH ; at beginning of string? JZ CW_RET ; yes, done JMP CTRL_W_LOOP EXTENDED_ASCII: GET_CHAR PUSH ES ; the second code is in AL now PUSH DI MOV DI, CS MOV ES, DI LEA DI, SECOND_CODE_TABLE MOV CX, CODE_TABLE_LENGTH CLD CLI ; we need CX after scan REPNE SCASB ; search for extended code in table STI SHL CX, 1 ; CX is now offset in jump-table MOV BP, CX POP DI POP ES JMP [BP+ECJT] INSERT_R: ;----- flip the insert-toggle ; NOT INSERT_TOGGLE CALL SET_CURSOR_TYPE RET DELETE_R: ;----- delete the character under the cursor ; CMP BL, BH ; if cursor at end JE DR_L2 ; then nothing to delete MOV AH, ES:[DI] ; remember victim for display update CALL MOVE_TAIL_LEFT ; remove from buffer DEC BL ; update total length ;----- next update display ; MOV CX, 1 ; at least one character to erase CMP AH, 20H ; control character ? JAE DR_L1 ; INC CX ; yes, erase the caret too CMP AH, TAB ; beware of the TAB JNE DR_L1 ; if TAB then some calculation required ; to determine shift of display CALL BACK_TAB DR_L1: CALL DISPLAY_TAIL DR_L2: RET CURSOR_LEFT_R: ;----- move current cursor position one to the left ; OR BH, BH JZ CL_ATBEGIN ; cursor at begin of string DEC DI ; update pointers DEC BH ; ;----- update display ; MOV CX, 1 ; set up for one backspace MOV AH, [DI] ; get character under cursor CMP AH, 20H ; if control-character then JAE CL_BS ; two backspaces are required INC CL ; if ctrl-char then two backspaces CMP AH, TAB ; exception: tab-character JNE CL_BS ; CALL BACK_TAB ; compute number of backspaces ; needed for this tab (returned in CL;) CL_BS: MOV AL, BACKSPACE CALL DISPLAY_COMPLEX LOOP CL_BS RET CL_ATBEGIN: CALL BEEP RET CURSOR_RIGHT_R: ;----- move current cursor position one to the right ; CMP BL, BH JE CR_AT_END ; cursor at end of string MOV AL, [DI] ; get character under cursor INC DI ; update pointers INC BH ; ;----- update display ; CMP AL, 20H JB CRR_L2 ;----- non-control ascii character, so ; cursor must move right one position ; see if this can be done by cursor control ; if not then redisplay character ; CMP FULL_EDIT, ON JNE CRR_L2 MOV AX, CURSOR_POS INC AL CMP AL, MAX_COL JB CRR_L1 CLR AL CMP AH, MAX_ROW - 1 JE CRR_L1 INC AH CRR_L1: MOV CURSOR_POS, AX CALL SET_CURSOR_POS RET CRR_L2: ;----- move cursor right by redisplaying the character ; which is under cursor now ; CALL DISPLAY_COMPLEX RET CR_AT_END: CALL BEEP RET PREV_LINE_R: ;------------------------------ ; empty the current buffer and get the one less ; recent string from the string buffer MOV BP, SP ; need access to buffer address ; which is saved on the stack PUSH STR_END_POS ; save current end of string on screen CALL CURSOR_BEGIN_R ;----- next find a new string to be edited ; MOV AX, C_TBL_HEAD ; take a look in the CMP AX, C_TBL_TAIL ; string pointer table JE PNL_EMPTY ; no string there ; proceed with empty string MOV BX, CURRENT ; CMP BX, AX ; determine previous entry JNE PL_L1 ; in TABLE, MOV BX, C_TBL_TAIL ; PL_L1: CALL SCROLLUP_TBL ; MOV CURRENT, BX ; and make it the current one MOV CX, CS:[BX] ; CMP BX, AX ; determine length of this JNE PL_L2 ; candidate by scrolling up MOV BX, C_TBL_TAIL ; another entry ... JMPS PL_L3 ; PL_L2: CALL SCROLLUP_TBL ; PL_L3: ; MOV SI, CS:[BX] ; ... and subtracting the PNL_L1: SUB CX, SI ; addresses of the strings' JA PNL_L2 ; last bytes. ADD CX, STR_BUF_SIZE; we have wrapped around in STR_BUF PNL_L2: JCXZ PNL_EMPTY MOV BL, CL ; CL now contains the candidate's MOV BH, CL ; length. CMP DL, CL ; initialize string-pointers JNB PNL_L3 CALL BEEP ; if too long ring bell twice (as long) CALL BEEP PNL_EMPTY: ADD SP, 4 ; discard return address and ; EOS which are on the stack JMP FI_RESTART ;----- the new string can be transferred now ; PNL_L3: MOV DI, [BP+2] ; get address of target buffer INC SI ; set source pointer PNL_L4: CMP SI, STR_BUF_END ; wrap-around in STR_BUF JNE PNL_L5 ; if nessecary MOV SI, STR_BUF_START PNL_L5: LODS BYTE PTR CS:[SI]; do the transfer STOSB ; CALL DISPLAY_COMPLEX ; display this byte LOOP PNL_L4 ; ;-----the pointers BH, BL, and DI are properly set up now ; the current cursor-position is at the end of the new string ; ;----- compute difference in string length ; POP CX ; recover saved STR_END_POS ; of previous string MOV AL, CH ; AL := (OLD)STR_END_ROW SUB CX, CURSOR_POS ; !! CX := CURSOR_POS - (OLD)STR_END_POS JBE PNL_L8 ; new > old ? SUB AL, CURSOR_ROW ; AL := CURSOR_ROW - (OLD)STR_END_ROW MOV AH, MAX_COL NEG AH MUL AH ; multiply by (256 - characters/column) SUB CX, AX ; compensate for subtraction !! ; CX := (oldROW - newROW)*MAX_COL + ; (oldCOL - newCOL) PUSH CX PNL_L6: MOV AL, ' ' ; blank out remnant characters CALL DISPLAY_COMPLEX LOOP PNL_L6 POP CX PNL_L7: MOV AL, BACKSPACE ; set cursor back CALL DISPLAY_COMPLEX LOOP PNL_L7 PNL_L8: PUSH CURSOR_POS POP STR_END_POS RET ; top of stack = address MAINLOOP NEXT_LINE_R: ;--------------------------- ; empty the current buffer and get the one more ; recent string from the string buffer MOV BP, SP ; need access to buffer address ; which is saved on the stack PUSH STR_END_POS ; save current end of string on screen CALL CURSOR_BEGIN_R ;----- find next string ; MOV AX, C_TBL_TAIL CMP AX, C_TBL_HEAD JE PNL_EMPTY ; no string found MOV BX, CURRENT MOV SI, CS:[BX] ; get current string's end CMP BX, AX ; current=tail ? JE NL_L2 ; yes, wraparound CALL SCROLLDO_TBL ; else, scroll down CMP BX, AX ; at tail now ? JNE NL_L3 ; no, go and update CURRENT MOV SI, CS:[BX] ; else, new old string's end NL_L2: MOV BX, C_TBL_HEAD ; wraparound NL_L3: MOV CURRENT, BX ; new current string MOV CX, CS:[BX] ; new string's end JMP PNL_L1 ; next check the length CURSOR_BEGIN_R: ;----- moves the cursor to the start of the buffer ; OR BH, BH ; is cursor at start ? JZ CBR_DONE ; if so then return CALL CURSOR_LEFT_R ; move one to the left JMP CURSOR_BEGIN_R ; and again until at start CBR_DONE: RET CURSOR_END_R: ;----- moves the cursor to the end of the buffer ; CMP BL, BH ; is cursor at end ? JE CER_DONE ; yes: return CALL CURSOR_RIGHT_R ; move one towards the end JMP CURSOR_END_R ; until done CER_DONE: RET F1_R: ;----- move cursor one word left ; CALL CURSOR_LEFT_R ; OR BH, BH ; move one character left JZ F1_L2 ; until a non-blank is CMP BYTE PTR [DI-1], ' ' ; reached JE F1_R ; F1_L1: CALL CURSOR_LEFT_R ; now move left until OR BH, BH ; the next blank JZ F1_L2 ; CMP BYTE PTR [DI-1], ' ' ; JNE F1_L1 F1_L2: ; RET F2_R: ;----- move cursor one word right ; CALL CURSOR_RIGHT_R ; CMP BL, BH ; move one character right JE F2_L2 ; until a blank is reached CMP BYTE PTR [DI], ' ' ; JNE F2_R F2_L1: CALL CURSOR_RIGHT_R OR BH, BH ; move on until the JZ F2_L2 ; next non-blank CMP BYTE PTR [DI], ' ' ; JE F2_L1 ; F2_L2: ; RET F3_R: ;----- erase from begin of the string to the current cursor position ; CLR CH MOV CL, BH JCXZ F3_L2 ; CX=0: we are at start of string F3_L1: PUSH CX ; save number of characters CALL BACKSPACE_R ; we are going to remove POP CX ; recover number of characters LOOP F3_L1 ; F3_L2: RET F4_R: ;----- erase from the current cursor position to the end ; CLR CH MOV CL, BL SUB CL, BH JZ F4_L2 CALL CURSOR_END_R F4_L1: PUSH CX CALL BACKSPACE_R POP CX LOOP F4_L1 F4_L2: RET F5_R: ;----- insert current string in STR_BUF and start editing a fresh one ; MOV BP, SP ; need access to buffer address ; which is saved on the stack CALL CURSOR_END_R MOV AL, '@' ; show what is going to happen CALL DISPLAY_CHAR ; MOV AL, CR CALL DISPLAY_CHAR MOV AL, LF CALL DISPLAY_CHAR MOV SI, [BP+2] ; get source pointer from stack CLR CH MOV CL, BL CALL STR_BUF_INSERT ADD SP, 2 ; discard return address on stack JMP FI_RESTART F6_R: ;----- End Of File character on function-key 6 ; MOV AL, EOF JMP M_L1 ; go insert this character F7_R: ;----- Nul on function-key 7 ; CLR AL JMP M_L1 ; go insert this character CTRL_LEFT_R: ;----- move cursor downwards ; MOV AX, CURSOR_TYPE CMP AL, CURSOR_MASK JE CTRL_LR_X INC AL INC AH MOV CURSOR_TYPE, AX CALL SET_CURSOR_TYPE CTRL_LR_X: RET CTRL_RIGHT_R: ;----- move cursor upwards ; MOV AX, CURSOR_TYPE OR AH, AH JZ CTRL_RR_X DEC AL DEC AH MOV CURSOR_TYPE, AX CALL SET_CURSOR_TYPE CTRL_RR_X: RET CTRL_HOME_R: ;----- move cursor-top downwards ; MOV AX, CURSOR_TYPE CMP AH, CURSOR_MASK JE CTRL_HR_X INC AH MOV CURSOR_TYPE, AX CALL SET_CURSOR_TYPE CTRL_HR_X: RET CTRL_END_R: ;----- move cursor-bottom downwards ; MOV AX, CURSOR_TYPE CMP AL, CURSOR_MASK JE CTRL_ER_X INC AL MOV CURSOR_TYPE, AX CALL SET_CURSOR_TYPE CTRL_ER_X: RET CTRL_PGUP_R: ;----- move cursor-top upwards ; MOV AX, CURSOR_TYPE OR AH, AH JZ CTRL_PU_X DEC AH MOV CURSOR_TYPE, AX CALL SET_CURSOR_TYPE CTRL_PU_X: RET CTRL_PGDN_R: ;----- move cursor-bottom upwards ; MOV AX, CURSOR_TYPE OR AL, AL JZ CTRL_PD_X DEC AL MOV CURSOR_TYPE, AX CALL SET_CURSOR_TYPE CTRL_PD_X: RET SHIFT_F5_R: ;----- decrement change in INSERT cursor-shape ; CMP INSERT_SHIFT, 0 JE SHIFT_F5_X DEC INSERT_SHIFT CALL SET_CURSOR_TYPE SHIFT_F5_X: RET SHIFT_F6_R: ;----- increment change in INSERT cursor-shape ; CMP INSERT_SHIFT, CURSOR_MASK JE SHIFT_F6_X INC INSERT_SHIFT CALL SET_CURSOR_TYPE SHIFT_F6_X: RET ALT_DIGIT: ;----- scroll up through previous strings a number of ; times given by the digit key which was pressed ; along with the ALT-key. ; SUB AL, ALT_1 ; make use of contiguous range of codes ; generated by the ALT-digit keys ; AL now in range 0 .. 9 CLR CH MOV CL, AL JCXZ DA_LX ; so ALT_1 same as arrow-up PUSH BX MOV BX, CURRENT ; get CURRENT DA_L1: CMP BX, C_TBL_HEAD ; at oldest string in table ? JNE DA_L2 ; if so, stop, no wrap around CALL SCROLLDO_TBL ; and undo last scrollup JMPS DA_L3 DA_L2: CALL SCROLLUP_TBL ; else one entry up LOOP DA_L1 ; repeat CX times DA_L3: MOV CURRENT, BX ; update CURRENT POP BX DA_LX: JMP PREV_LINE_R ; MAIN_LOOP_RETURN: ;----- no match in extended ascii found, return to main loop ; RET MAIN_LOOP ENDP REQ_HDR STRUC LENGTH DB ? UNIT DB ? COMMAND DB ? STATUS DW ? RESERV DB 8 DUP(?) REQ_HDR ENDS INIT_HDR STRUC DB SIZE REQ_HDR DUP(?) NO_UNITS DB ? END_ADR DD ? PARMS DD ? INIT_HDR ENDS IO_HDR STRUC DB SIZE REQ_HDR DUP(?) MEDIA DB ? BUFFER_ADR DD ? COUNT DW ? IO_HDR ENDS ;-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ; ; D E V I C E S T R A T E G Y ( ENTRY POINT ) ; ;-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* D_STRATEGY PROC FAR ;----- save request header address ; MOV REQ_HEADER_OFS, BX MOV REQ_HEADER_SEG, ES RET D_STRATEGY ENDP D_F_TABLE LABEL WORD ; this table contains routine addresses ; for the device-driver functions DW D_INIT ; 0: driver initialization DW D_NOP ; 1: media check DW D_NOP ; 2: build BPB DW D_IOCTL_IN ; 3: IO-control input DW D_INPUT ; 4: input DW D_NON_DSTR_IN ; 5: non-destructive input DW D_INPUT_STATUS ; 6: input status DW D_INPUT_FLUSH ; 7: input flush DW D_OUTPUT ; 8: output DW D_OUTPUT_VER ; 9: output with verify DW D_OUTPUT_STATUS ; 10: output status DW D_OUTPUT_FLUSH ; 11: output flush DW D_IOCTL_OUT ; 12: IO-control output DW D_OPEN ; 13: device open DW D_CLOSE ; 14: device close DW D_NOP ; 15: removable media D_F_TABLE_LEN = $ - D_F_TABLE ;-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ; ; D E V I C E I N T E R R U P T ( ENTRY POINT ) ; ;-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* D_INTERRUPT PROC FAR ; STI PUSH ES ; PUSH DS ; PUSH BP ; save PUSH DI ; registers PUSH SI ; PUSH DX ; PUSH CX ; PUSH BX ; PUSH AX CALL SETSTACK ; to internal stack MOV BIOS_TTY_SW, ON MOV ES, REQ_HEADER_SEG ; get request- MOV BX, REQ_HEADER_OFS ; header block MOV AL, ES: [BX].COMMAND ; get opcode CLR AH SHL AX, 1 CMP AX, D_F_TABLE_LEN JAE D_ERROR MOV SI, AX JMP D_F_TABLE[SI] ; do request ;----- it is assumed that all routines preserve ; the ES:BX pointer to the Request Header ; D_ERROR: OR ES: [BX].STATUS, 8003H ; invalid code D_EXIT: OR ES: [BX].STATUS, 0100H ; status_ok MOV BIOS_TTY_SW, OFF CALL RESETSTACK ; back to ; callers stack POP AX POP BX POP CX ; POP DX ; POP SI ; restore POP DI ; registers POP BP ; POP DS ; POP ES ; RET D_INTERRUPT ENDP D_NOP : D_IOCTL_IN : D_INPUT : D_NON_DSTR_IN : D_INPUT_STATUS : D_INPUT_FLUSH : D_OUTPUT_STATUS : D_OUTPUT_FLUSH : D_IOCTL_OUT : D_OPEN : D_CLOSE : JMP D_ERROR INSTALL_BUF PROC NEAR ;*************************************************************** ;* Redirect the DOS-keyboard-buffer pointers to enlarged buffer ;* Copy old buffer contents to the new buffer ;*************************************************************** PUSH DS CMP KB_INST, ON ; JNE IB_L1 ; buffer is already here LEA SI, MSG_KB_PR ; already present message JMP IB_LX IB_L1: CMP KBBUFFER_SIZE, 32 ; worth the trouble ? JA IB_L2 ; LEA SI, MSG_KB_NO_1 ; message: no succes CALL PRINT MOV AX, KBBUFFER_SIZE SHR AX, 1 CALL PRINT_NUM LEA SI, MSG_KB_NO_2 JMP IB_LX IB_L2: ASSUME DS: DOS_DATA_AREA ; MOV AX, DOS_DATA_AREA ; data segment on MOV DS, AX ; DOS-OS Data CLR DI MOV BX, KBBUFFER CLI MOV SI, KB_HEAD ; move any data already IB_L3: CMP SI, KB_TAIL ; in the DOS-buffer to JE IB_L4 ; new buffer CMP DI, 32 ; can not copy indefinitely JE IB_L4 ; because new buffer overlays ; initialization code MOV AX, [SI] ; MOV CS: [BX+DI], AX ; transfer item INC DI ; keep character count INC DI ; INC SI ; INC SI ; CMP SI, DOS_BUFFER_END ; wraparound if JNE IB_L3 ; neccesary MOV SI, DOS_BUFFER_START ; JMP IB_L3 ; IB_L4: MOV AX, DOS_BUFFER_START MOV OLD_DOS_BUFFER_START, AX MOV AX, DOS_BUFFER_END MOV OLD_DOS_BUFFER_END, AX MOV AX, CS ; SUB AX, DOS_DATA_AREA ; make AX point to offset MOV CL, 4 ; KBBUFFER relative to SHL AX, CL ; segment DOS_DATA_AREA ADD AX, KBBUFFER ; MOV DOS_BUFFER_START, AX ; MOV KB_HEAD, AX ; change pointers to MOV KB_TAIL, AX ; our own buffer ADD KB_TAIL, DI ; ADD AX, KBBUFFER_SIZE ; add number of characters MOV DOS_BUFFER_END, AX ; taken over from old buffer STI ASSUME DS: NOTHING MOV KB_INST, ON ; presence-flag on LEA SI, MSG_KB_IN ; message: succes CALL PRINT LEA SI, MSG_KB_1 ; give size of buffer CALL PRINT MOV AX, KBBUFFER_SIZE SHR AX, 1 CALL PRINT_NUM LEA SI, MSG_KB_2 IB_LX: CALL PRINT ; POP DS RET INSTALL_BUF ENDP UNINSTALL_BUF PROC NEAR ;************************************************ ;* Restore original keyboard buffer pointers ;************************************************* PUSH DS CMP KB_INST, OFF JE UB_L1 ASSUME DS: DOS_DATA_AREA ; MOV AX, DOS_DATA_AREA ; data segment on MOV DS, AX ; DOS-OS Data CLI MOV AX, OLD_DOS_BUFFER_START MOV DOS_BUFFER_START, AX ; restore old MOV KB_HEAD, AX ; buffer addresses MOV KB_TAIL, AX ; note: MOV AX, OLD_DOS_BUFFER_END ; buffer is flushed MOV DOS_BUFFER_END, AX STI ASSUME DS: NOTHING MOV KB_INST, OFF LEA SI, MSG_KB_UN ; buffer-gone message JMPS UB_LX UB_L1: LEA SI, MSG_KB_NOT_PR ; error message UB_LX: CALL PRINT ; display message POP DS RET UNINSTALL_BUF ENDP INSTALL_ED PROC NEAR ;********************************************************** ;* Redirect interrupt 21H function 0AH to enable enhanced ;* editing and buffering ;********************************************************** PUSH ES CMP EDT_INST, ON ; JE IE_L2 ; editor already installed CMP EDT_INST, NOT_INST ; test for first turn on MOV EDT_INST, ON ; presence-flag on JNE IE_L1 ; install INT21H interrupt ; address, if not already done CLR AX ; segment 0 for interrupt- MOV ES, AX ; address manipulation LES BX, ES: [DOS_FUNCTION_INT] ; save old address MOV WORD PTR OLD_FUNCTION_INT, BX MOV WORD PTR OLD_FUNCTION_INT[2], ES MOV ES, AX ; replace with new address CLI MOV ES: [DOS_FUNCTION_INT], OFFSET FUNCTION_INT_ENTRY MOV ES: [DOS_FUNCTION_INT + 2], CS STI IE_L1: LEA SI, MSG_EDT_IN ; reinitialize message CALL PRINT LEA SI, MSG_EDT_1 ; editor specification CALL PRINT MOV AX, STR_BUF_SIZE CALL PRINT_NUM LEA SI, MSG_EDT_2 CALL PRINT MOV AX, C_TBL_SIZE SHR AX, 1 ; size in bytes --> no-of-entries DEC AX ; table-size = entries - 1 CALL PRINT_NUM LEA SI, MSG_EDT_3 JMPS IE_LX IE_L2: LEA SI, MSG_EDT_PR ; already present message IE_LX: CALL PRINT ; POP ES RET INSTALL_ED ENDP UNINSTALL_ED PROC NEAR ;***************************************************** ;* restore INT 21H interrupt address ;* if not possible, zero flag is OFF at exit ;***************************************************** PUSH ES CMP EDT_INST, ON JNE UE_L2 MOV EDT_INST, OFF CLR AX MOV ES, AX ;----- check whether our address still in vector ; CMP ES: [DOS_FUNCTION_INT], OFFSET FUNCTION_INT_ENTRY JNE UE_L1 MOV AX, CS CMP ES: [DOS_FUNCTION_INT + 2], AX JNE UE_L1 ;----- OK, undo revectoring ; MOV AX, WORD PTR OLD_FUNCTION_INT MOV ES: [DOS_FUNCTION_INT], AX MOV AX, WORD PTR OLD_FUNCTION_INT[2] MOV ES: [DOS_FUNCTION_INT + 2], AX MOV EDT_INST, NOT_INST UE_L1: LEA SI, MSG_EDT_UN ; editor-gone message JMPS UE_LX UE_L2: LEA SI, MSG_EDT_NOT_PR UE_LX: CALL PRINT ; editor-already-gone message POP ES RET UNINSTALL_ED ENDP RESET_EDT PROC NEAR MOV AX, C_TBL_START MOV C_TBL_HEAD, AX MOV C_TBL_TAIL, AX MOV CURRENT, AX RET RESET_EDT ENDP INSTALL_ANSI PROC NEAR MOV ANSI, ON MOV MAX_COL, 80 RET INSTALL_ANSI ENDP UNINSTALL_ANSI PROC NEAR MOV ANSI, OFF RET UNINSTALL_ANSI ENDP RECALL PROC NEAR ;----- display all strings in STR_BUF ; CLR DX ; initialize MOV DI, C_TBL_SIZE ; DX = sequence number SHR DI, 1 ; DI = maximum number of strings DEC DI ; MOV BX, C_TBL_TAIL ; BX = pointer into C_TBL entry MOV SI, CS:[BX] ; of string currently displayed MOV BX, C_TBL_HEAD ; REC_L1: CMP BX, C_TBL_TAIL ; JE REC_LX ; all strings done, normal exit MOV AL, CR CALL WRITE_CHAR MOV AL, LF CALL WRITE_CHAR INC DX CMP DX, DI ; savety check, prevent endless looping JA RESET_EDT ; this jump should not occur, error exit MOV AX, DX CALL PRINT_NUM MOV AL, '.' CALL WRITE_CHAR MOV AL, ' ' CALL WRITE_CHAR MOV CX, CS:[BX] ; last character of string SUB CX, SI ; compute length JAE REC_L2 ADD CX, STR_BUF_SIZE REC_L2: INC SI ; next character CMP SI, STR_BUF_END JNE REC_L3 ; wrap around if necessary MOV SI, STR_BUF_START REC_L3: MOV AL, CS:[SI] CALL DISPLAY_COMPLEX LOOP REC_L2 CALL SCROLLDO_TBL JMP REC_L1 REC_LX: RET RECALL ENDP D_OUTPUT: D_OUTPUT_VER: ;************************************************************ ;* Output routine. ;* Characters output to this device are interpreted as ;* control codes to switch the editor and buffer on and off. ;* Such control codes consist always of two characters: ;* "IK" = Install Keyboard Buffer. ;* "IE" = Install Keyboard Editor. ;* "UK" = Uninstall Keyboard Buffer. ;* "UE" = Uninstall Keyboard Editor. ;* "RE" = Reset Editor ;* "IA" = ANSI mode On ;* "UA" = ANSI mode Off ;* ;* On entry: ES:BX contains long pointer to Request Header ;************************************************************ PUSH ES PUSH BX MOV CX, ES: [BX].COUNT ; number of characters in CX OR CX, CX ; JZ O_LX ; check for a mistake LES BX, ES: [BX].BUFFER_ADR ; load address of buffer MOV AL, ES: [BX] ; get first character from buffer CMP EXPECTSECOND, ON; second part expected? JE O_L1 ; yes: treat second part MOV FIRSTPART, AL ; no: save this first part MOV EXPECTSECOND, ON; now we do expect the second part CMP CX, 1 ; was there more then one? JBE O_LX ; no: wait for next arrival MOV AL, ES: [BX+1] ; yes: get second character ;----- at this point there is a complete command ; and we are ready for interpreting ; O_L1: MOV EXPECTSECOND, OFF MOV AH, FIRSTPART ; AX now contains the ; two letter code AND AX, 0DFDFH ; capitalize CMP AX, 'IK' ; JNE O_L2 CALL INSTALL_BUF ; code = 'IK' JMPS O_LX O_L2: CMP AX, 'IE' ; JNE O_L3 CALL INSTALL_ED ; code = 'IE' JMPS O_LX O_L3: CMP AX, 'UK' ; JNE O_L4 CALL UNINSTALL_BUF ; code = 'UK' JMPS O_LX O_L4: CMP AX, 'UE' ; JNE O_L6 CALL UNINSTALL_ED ; code = 'UE' JMPS O_LX O_L6: CMP AX, 'IA' ; JNE O_L7 CALL INSTALL_ANSI ; code = 'IA' JMPS O_LX O_L7: CMP AX, 'UA' ; JNE O_L8 CALL UNINSTALL_ANSI ; code = 'UA' JMPS O_LX O_L8: CMP AX, 'RC' ; JNE O_L9 CALL RECALL ; code = 'UA' JMPS O_LX O_L9: CMP AX, 'RE' JNE O_LX CALL RESET_EDT ; code = 'RE' ;----- otherwise invalid combination ; O_LX: POP BX POP ES JMP D_EXIT ; to exit protocol ;----- round origin to paragraph boundary ; ORG ($ - START_CODE + 15) AND 0FFF0H END_CODE = $ ACTIVATE DB OFF ; activate immediate switch P_CHAR_COUNT DW ? ; character count on parameter line MSG_INVA_SW_1 DB ' Invalid switch at position : ', NULL MSG_INVA_SW_2 DB ' in Configuration file' DB CR, LF, LF, NULL MSG_INVA_CHR_1 DB ' Invalid character at position : ', NULL MSG_INVA_CHR_2 DB ' in Configuration file' DB CR, LF, LF, NULL MSG_ADR_OVL DB ' Buffer sizes too large, reduce parameter values' DB ' in Configuration file' DB CR, LF DB ' Default values substituted' DB CR, LF, LF, NULL MSG_OVL_1 DB ' Parameter value overflow at position: ', NULL MSG_OVL_2 DB ' in Configuration file' DB CR, LF, NULL MSG_ADJUST_1 DB ' Specified size for keyboard buffer too large,' DB ' size adjusted to : ', NULL MSG_ADJUST_2 DB ' bytes', CR, LF, NULL GET_PARMS PROC NEAR ;************************************************************* ; This procedure scans the string addressed by DS:SI for ; the presence of parameters to the driver. ; ; Parameters must have the following format: ; ; DEVICE=\path\drv_name K:nnn B:nnn C:nnn [/A] [/N] ; ; where nnn is a decimal number. ; ; K:nnn nnn is keyboard buffer size ; B:nnn nnn is buffer size for command strings ; C:nnn nnn is maximum number of commands that can be stored ; /A if present: activation on driver installation ; /N if present: cursor control through ANSI-codes ; ; ; The code should implement the following: ; ; ---------------------- ; ; C: CHAR; ; Separators = [NULL, ' ', ',', '=', ';', '+', TAB]; ; ; ON EndOfLine: EXIT; ; REPEAT GetChar(C) UNTIL C IN Separators; ; REPEAT ; WHILE (C IN Separators) DO GetChar(C); ; CASE C OF ; 'K': OUT1 := GetNum; ; 'B': OUT2 := GetNum; ; 'C': OUT3 := GetNum; ; '/': [GetChar(C); IF C='A' THEN ACTIVATE := ON ; ELSE IF C='N' THEN ANSI := ON ; ]; ; ; UNTIL EndOfLine; ; ; GetNum: ; GetNum := 0; ; IF C = ':' THEN GetChar(C); ; WHILE (C IN ['0'..'9']) DO [ ; GetNum := GetNum*10 + (Ord(C) - Ord('0')); ; GetChar(C) ; ]; ; ; --------------------- ; ; LDS SI, ES: [BX].PARMS MOV P_CHAR_COUNT, 7 ; assume 'DEVICE=' occupies ; first 7 positions in CONFIG GP_L1: CALL GET_P_CHAR JZ GP_LX CALL IN_SEPARATORS JNZ GP_L1 GP_NEXT: CALL GET_P_CHAR JZ GP_LX CALL IN_SEPARATORS JZ GP_NEXT CMP AL, 'K' JNE GP_LB ;----- collect keyboard buffer size ; CALL GET_NUM OR CX, CX ; check result JZ GP_LK1 ; zero ? JS GP_LO ; > 32K ? SHL CX, 1 ; each keystroke fills two bytes MOV KBBUFFER_SIZE, CX ; in buffer GP_LK1: JMP GP_NEXT GP_LB: CMP AL, 'B' JNE GP_LC ;----- collect string buffer size ; CALL GET_NUM OR CX, CX ; check result JZ GP_LB1 MOV STR_BUF_SIZE, CX GP_LB1: JMP GP_NEXT GP_LC: CMP AL, 'C' JNE GP_LS ;----- collect maximum number of commands ; CALL GET_NUM OR CX, CX ; check result JZ GP_LC1 INC CX ; table-size = no-of-entries + 1 JS GP_LO ; > 32K ? SHL CX, 1 ; CX = no-of-entries, convert to bytes MOV C_TBL_SIZE, CX GP_LC1: JMP GP_NEXT GP_LX: RET GP_LS: CMP AL, '/' JNE GP_L6 ;----- collect switches ; CALL GET_P_CHAR JZ GP_LX CMP AL, 'A' JNE GP_LS1 MOV ACTIVATE, ON JMP GP_NEXT GP_LS1: CMP AL, 'N' JNE GP_LS2 MOV ANSI, ON JMP GP_NEXT GP_LS2: ;----- invalid switch ; PUSH SI LEA SI, MSG_INVA_SW_1 CALL PRINT MOV AX, P_CHAR_COUNT CALL PRINT_NUM LEA SI, MSG_INVA_SW_2 CALL PRINT POP SI JMP GP_L1 GP_LO: ;----- overflow ; PUSH SI LEA SI, MSG_OVL_1 CALL PRINT MOV AX, P_CHAR_COUNT DEC AX CALL PRINT_NUM LEA SI, MSG_OVL_2 CALL PRINT POP SI JMP GP_NEXT GP_L6: ;----- invalid character on line ; PUSH SI LEA SI, MSG_INVA_CHR_1 CALL PRINT MOV AX, P_CHAR_COUNT CALL PRINT_NUM LEA SI, MSG_INVA_CHR_2 CALL PRINT POP SI JMP GP_L1 ; go on after next separator IN_SEPARATORS PROC NEAR ;----- determine if character is in the separator set ; in: AL: character ; return: zero flag set if Al in separators ; !! CR and LF are also return zero ; CMP AL, NULL JE IS_LX CMP AL, ' ' JE IS_LX CMP AL, ',' JE IS_LX CMP AL, '=' JE IS_LX CMP AL, '+' JE IS_LX CMP AL, ';' JE IS_LX CMP AL, TAB JE IS_LX CMP AL, CR JE IS_LX CMP AL, LF IS_LX: RET IN_SEPARATORS ENDP GET_P_CHAR PROC NEAR ;----- return next character from parameter-string in AL ; if EndOfLine reached then zero-flag is set ; CMP AL, CR JE GPC_LX LODSB INC P_CHAR_COUNT CMP AL, CR JE GPC_LX CMP AL, LF GPC_LX: RET GET_P_CHAR ENDP PUT_P_CHAR PROC NEAR ;----- reverse last action of GET_P_CHAR ; AL is pushed back onto the "input-stream" ; DEC SI DEC P_CHAR_COUNT RET PUT_P_CHAR ENDP GET_NUM PROC NEAR ;----- read a decimal number from parameter string ; out: CX contains the number ; this routine reads only digits, when an other ; character is read it is pushed back through ; PUT_P_CHAR and the routine exits ; CLR CX CALL GET_P_CHAR JZ GN_LX CMP AL, ':' JNE GN_L2 GN_L1: CALL GET_P_CHAR JZ GN_LX GN_L2: CMP AL, '9' ; test for digit JA GN_LX CMP AL, '0' JB GN_LX SUB AL, '0' XCHG CX, AX ; multiplication operand in AX MUL TEN ; x 10 XCHG CX, AX JNC GN_L3 ; test for overflow CLR CX ; if so, return zero JMPS GN_LX1 GN_L3: CLR AH ; ADD CX, AX ; add next digit JMP GN_L1 GN_LX: CALL PUT_P_CHAR GN_LX1: RET GET_NUM ENDP GET_PARMS ENDP D_INIT PROC NEAR ;************************************************************ ;* Driver initialization routine. ;* ;* !! version 2.0 only installs driver at boot-time ;* !! NO immediate activation of buffers and editor ;************************************************************ PUSH ES PUSH BX MOV BIOS_TTY_SW, ON MOV AX, CS MOV DS, AX ; tell about the instal- LEA SI, MSG_VERSION ; lation of this driver CALL PRINT ; CALL GET_PARMS ;----- check the parameters ; MOV CL, 4 MOV AX, KBBUFFER_SIZE ; compute end of KBBUFFER ADD AX, 0FH ; SHR AX, CL ; paragraph format ADD AX, (END_CODE - START_CODE) SHR 4 MOV CX, CS ; add segment paragraph number ADD AX, CX ; SUB AX, 1000H ; must not exceed first 64K JBE D_IN_L2 MOV CL, 4 ; SHL AX, CL ; in bytes again SUB KBBUFFER_SIZE, AX ; adjust KBBUFFER_SIZE JNC D_IN_L1 ; no negative values MOV KBBUFFER_SIZE, 0 D_IN_L1: LEA SI, MSG_ADJUST_1 ; CALL PRINT ; display message MOV AX, KBBUFFER_SIZE ; and new size of KBBUFFER CALL PRINT_NUM ; LEA SI, MSG_ADJUST_2 ; CALL PRINT D_IN_L2: LEA AX, END_CODE MOV KBBUFFER, AX ; set start address of KB-buffer ADD AX, KBBUFFER_SIZE MOV STR_BUF_START, AX ; initialize command string MOV STR_BUF_HEAD, AX ; buffer data-structure MOV STR_BUF_TAIL, AX ; ADD AX, STR_BUF_SIZE ; JC D_IN_ERR ; test for overflow MOV STR_BUF_END, AX ; MOV SI, AX ; initialize first entry MOV CS:[SI], AX ; in C_TBL with address of DEC WORD PTR CS:[SI] ; last byte in STR_BUF MOV C_TBL_START, AX ; start address of C_TBL MOV C_TBL_HEAD, AX ; MOV C_TBL_TAIL, AX ; MOV CURRENT, AX ADD AX, C_TBL_SIZE ; now AX = end of resident code JC D_IN_ERR ; test for overflow MOV C_TBL_END, AX ; end of C_TBL ;----- fill in in Request Header ; MOV WORD PTR ES: [BX].END_ADR, AX MOV WORD PTR ES: [BX].END_ADR+2, CS CMP ACTIVATE, ON ; /A switch present ? JNE D_IN_LX CALL INSTALL_BUF ; if so, install now CALL INSTALL_ED ; D_IN_LX: MOV BIOS_TTY_SW, OFF ; display through DOS POP BX POP ES JMP D_EXIT ; initialization done: ; to exit protocol D_IN_ERR: LEA SI, MSG_ADR_OVL ; address-overflow message CALL PRINT ; MOV C_TBL_SIZE, 32 ; set default values MOV STR_BUF_SIZE, 512 ; these values should not MOV ACTIVATE, OFF ; cause trouble JMP D_IN_L2 ; try again D_INIT ENDP CODE ENDS END