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- page 66, 132
- ;--- nansi.asm ----------------------------------------------------------
- ; New ANSI terminal driver.
- ; Optimized for speed in the case of multi-character write requests.
- ; (C) 1986 Daniel Kegel, Pasadena, CA
- ; May be distributed for educational and personal use only
- ; The following files make up the driver:
- ; nansi.asm - all DOS function handlers except init
- ; nansi_p.asm - parameter parser for ANSI escape sequences
- ; nansi_f.asm - ANSI command handlers
- ; nansi_i.asm - init DOS function handler
- ;
- ; Daniel Kegel, Bellevue, Washington & Pasadena, California
- ; Revision history:
- ; 5 july 85: brought up non-ANSI portion except forgot backspace
- ; 6 july 85: split off ANSI stuff into other files, added backspace
- ; 11 july 85: fixed horrible bug in getchar; changed dosfns to subroutines
- ; 12 july 85: fixed some scrolling bugs, began adding compaq flag
- ; 9 aug 85: added cursor position reporting
- ; 10 aug 85: added output character translation
- ; 11 aug 85: added keyboard redefinition, some EGA 80x43 support
- ; 10 sept 85: Tandy 2000 support via compaq flag (finding refresh buffer)
- ; 30 Jan 86: removed Tandy 2000 stuff, added graphics mode support
- ; 12 feb 86: added int 29h handler, added PUSHA/POPA, added direct beep,
- ; direct cursor positioning, takeover of BIOS write_tty,
- ; noticed & squashed 2 related bugs in tab expansion
- ; 13 feb 86: Squashed them again, harder
- ; 24 feb 86: There is a bug in the timing code used by the BEEP routine.
- ; If the addition of the beep period to the
- ; BIOS low timer word results in an overflow, the beep will be
- ; supressed. Also made code compatible eith earlier versions
- ; of assembler.
- ; 8 july 86: Changed version number to reflect bug fix in nansi_f.asm
- ; 9 Aug 86: Added "snow_flag", snow mode code, "pseudo_flag"
- ; 11 aug 86: added snow_stosw
- ; 22 feb 90: modified to skip nulls C.R. Henderson (CRH)
- ; 23 feb 90: modified to perform a non-overwrite TAB expansion (CRH)
- ; 9 mar 90: modified to stuff 'nansi' followed by a carriage return (CRH)
- ; into the keyboard buffer in response to a ESC[c command
- ; 30 Oct 90: Merged crh's 2.2 mods with 2.4 -- Howard Chu
- ;------------------------------------------------------------------------
-
- include nansi_d.asm ; definitions
-
- ; from nansi_f.asm
- extrn f_escape:near, f_in_escape:near
-
- ; from nansi_p.asm
- extrn param_end:word, redef_end:word
-
- ; from nansi_i.asm
- extrn dosfn0:near
-
- ; to nansi_p.asm
- public f_loopdone
- public f_not_ansi
- public f_ansi_exit
-
- ; to both nansi_p.asm and nansi_f.asm
- public cur_x, cur_y, max_x, cur_attrib
- public sr_min_y, sr_max_y
-
- ; to nansi_f.asm
- public snow_flag, pseudo_flag
- public xy_to_regs, get_blank_attrib
- public port_6845
- public wrap_flag
- public cur_parm_ptr
- public cur_coords, saved_coords, max_y
- public escvector, string_term
- public cpr_esc, cprseq
- public id_str, id_end, idseq ; CRH 3-9-90
- public video_mode
- public lookup
- public in_g_mode
- public snow_stosw, snow_movsw
-
- ; to nansi_i.asm
- public req_ptr, break_handler
- public int_29
- if takeBIOS
- public new_vid_bios, old_vid_bios
- endif
-
- ; to all modules
- public xlate_tab_ptr
-
- ;--- seg_cs is the CS: override prefix
- ; (assembler forgets cs: on second "xlat dummy_cs_byte")
- seg_cs macro
- db 2eh
- endm
-
- ;--- push_all, pop_all ------------------------------------------------
- ; Save/restore all user registers.
- push_all macro
- if is_8088
- push ax
- push bx
- push cx
- push dx
- push bp
- push si
- push di
- else
- pusha
- endif
- endm
-
- pop_all macro
- if is_8088
- pop di
- pop si
- pop bp
- pop dx
- pop cx
- pop bx
- pop ax
- else
- popa
- endif
- endm
-
- keybuf struc ; Used in getchar
- len dw ?
- adr dw ?
- keybuf ends
-
-
- ABS40 segment at 40h
- org 1ah
- buffer_head dw ? ; Used in 'flush input buffer' dos call.
- buffer_tail dw ?
-
- org 49h
- crt_mode db ?
- crt_cols dw ?
- crt_len dw ?
- crt_start dw ?
- cursor_posn dw 8 dup (?)
- cursor_mode dw ?
- active_page db ?
- addr_6845 dw ?
- crt_mode_set db ? ; = 7 only if monochrome display adaptor
- crt_palette db ?
- org 6ch
- timer_low dw ? ; low word of time-of-day counter (18.2 hz)
-
- ABS40 ends
-
- page
-
- CODE segment byte public 'CODE'
- assume cs:code, ds:code
-
- ; Device Driver Header
-
- org 0
-
- dd -1 ; next device
- dw 8013h ; attributes
- dw strategy ; request header pointer entry
- dw interrupt ; request entry point
- db 'CON' ; device name (8 char)
- db 5 dup (20h) ; pad with blanks
-
- ; Identification- in case somebody TYPEs the assembled driver
- db 27, '[2J'
- db 'Nansi.sys v2.4: New ANSI driver (C) Daniel Kegel, Rochester, NY 1986'
- db 13, 10, 'With modifications by Howard Chu @ University of Michigan, 10-30-90'
- db 13, 10, 26
-
-
- ;----- variable area --------------------
- req_ptr label dword
- req_off dw ?
- req_seg dw ?
-
- pseudo_flag db 1 ; 1 = simulate cursor in graphics modes
- snow_flag db 0 ; 1 = wait for retrace before writing
- wrap_flag db 1 ; 0 = no wrap past line end
- escvector dw 0 ; state vector of ESCape sequencor
- video_mode db 3 ; ROM BIOS video mode (2=BW, 3=color)
- max_y db 24
- max_cur_x label word ; used to get both max & cur at once
- max_x db 79 ; line width (79 for 80x25 modes)
- cur_coords label word
- cur_x db 0 ; cursor position (0 = left edge)
- cur_y db 0 ; (0 = top edge)
- saved_coords dw ? ; holds XY after a SCP escape sequence
- string_term db 0 ; either escape or double quote
- cur_attrib db 7 ; current char attributes
- cur_page db 0 ; current display page
- video_seg dw ? ; segment of video card
- f_cptr_seg dw ? ; part of fastout write buffer pointer
- cur_parm_ptr dw ? ; last byte of parm area now used
- port_6845 dw ? ; port address of 6845 card
- xlate_tab_ptr dw ? ; pointer to output translation table
- sr_min_y db ? ; 0 based; first line of scrolling region
- sr_max_y db ? ; 0 based; last line of scrolling region
- if takeBIOS
- old_vid_bios dd ? ; pointer to old video bios routine
- endif
-
- brkkeybuf db 3 ; control C
- fnkeybuf db ? ; holds second byte of fn key codes
- cpr_buf db 8 dup (?), '['
- cpr_esc db 1bh ; descending buffer for cpr function
- id_str db 13,"isna"
- id_end db 'n'
-
- ; following four keybufs hold information about input
- ; Storage order determines priority- since the characters making up a function
- ; key code must never be separated (say, by a Control-Break), they have the
- ; highest priority, and so on. Keyboard keys (except ctrl-break) have the
- ; lowest priority.
-
- fnkey keybuf <0, fnkeybuf> ; fn key string (0 followed by scan code)
- cprseq keybuf <0> ; CPR string (ESC [ y;x R)
- brkkey keybuf <0, brkkeybuf> ; ^C
- xlatseq keybuf <0> ; keyboard reassignment string
- idseq keybuf <0> ; response to ESC [ c CRH 3-9-90
-
- ;------ xy_to_regs --------------------------------------------
- ; on entry: x in cur_x, y in cur_y
- ; on exit: dx = chars left on line, di = address
- ; Alters ax, bx.
- xy_to_regs proc near
- ; Find number of chars 'till end of line, keep in DX
- mov ax, max_cur_x
- mov bx, ax ; save max_x & cur_x for next block
- mov ah, 0 ; ax = max_x
- xchg dx, ax
- mov al, bh
- mov ah, 0 ; ax = cur_x
- sub dx, ax
- inc dx ; dx is # of chars till EOL
- ; Calculate DI = current address in text buffer
- mov al, bl ; al = max_x
- inc al
- mul cur_y
- add al, bh ; al += cur_x
- adc ah, 0 ; AX is # of chars into buffer
- add ax, ax
- xchg di, ax ; DI is now offset of cursor.
- ret
- xy_to_regs endp
-
-
- ;------- dos_fn_tab -------------
- ; This table is used in "interrupt" to call the routine that handles
- ; the requested function.
-
- max_cmd equ 12 ; number of commands
- dos_fn_tab:
- dw dosfn0, nopcmd, nopcmd, badcmd, dosfn4, dosfn5, dosfn6
- dw dosfn7, dosfn8, dosfn8, nopcmd, nopcmd
-
- ;------- strategy ----------------------------------------------------
- ; DOS calls strategy with a request which is to be executed later.
- ; Strategy just saves the request.
-
- strategy proc far
- mov cs:req_off,BX
- mov cs:req_seg,ES
- ret
- strategy endp
-
- ;------ interrupt -----------------------------------------------------
- ; This is where the request handed us during "strategy" is
- ; actually carried out.
- ; Calls one of 12 subroutines depending on the function requested.
- ; Each subroutine returns with exit status in AX.
-
- interrupt proc far
- sti
- push_all ; preserve caller's registers
- push ds
- push es
-
- ; Read requested function information into registers
- lds bx, dword ptr cs:req_ptr
- mov al,[BX+02h] ; al = function code
- cbw
- les si,[BX+0Eh] ; ES:SI = input/output buffer addr
- mov cx,[BX+12h] ; cx = input/output byte count
-
- cmp al, max_cmd
- jae unk_command ; too big, exit with error code
-
- xchg bx, ax
- shl bx, 1 ; form index to table of words
- mov ax, cs
- mov ds, ax
- call word ptr dos_fn_tab[bx]
- int_done:
- lds bx, dword ptr cs:req_ptr; report status
- or ax, 100h ; (always set done bit upon exit)
- mov [bx+03],ax
-
- pop ES ; restore caller's registers
- pop DS
- pop_all
- ret ; return to DOS.
-
- unk_command:
- call badcmd
- jmp int_done
-
- interrupt endp
-
- ;----- BIOS break handler -----------------------------------------
- ; Called by BIOS when Control-Break is hit (vector was set up in Init).
- ; Simply notes that a break was hit. Flag is checked during input calls.
-
- break_handler proc
- mov cs:brkkey.len, 1
- iret
- break_handler endp
-
- page
-
- ;------ badcmd -------------------------------------------------------
- ; Invalid function request by DOS.
- badcmd proc near
- mov ax, 813h ; return "Error: invalid cmd"
- ret
- badcmd endp
-
-
- ;------ nopcmd -------------------------------------------------------
- ; Unimplemented or dummy function request by DOS.
- nopcmd proc near
- xor ax, ax ; No error, not busy.
- ret
- nopcmd endp
-
- ;------- dos function #4 ----------------------------------------
- ; Reads CX characters from the keyboard, places them in buffer at
- ; ES:SI.
- dosfn4 proc near
- jcxz dos4done
- mov di, si
- dos4lp: push cx
- call getchar
- pop cx
- stosb
- loop dos4lp
- dos4done:
- xor ax, ax ; No error, not busy.
- ret
- dosfn4 endp
-
- ;-------- dos function #5: non-destructive input, no wait ------
- ; One-character lookahead into the keyboard buffer.
- ; If no characters in buffer, return BUSY; otherwise, get value of first
- ; character of buffer, stuff into request header, return DONE.
- dosfn5 proc near
- call peekchar
- jz dos5_busy
-
- lds bx,req_ptr
- mov [bx+0Dh], al
- xor ax, ax ; No error, not busy.
- jmp short dos5_exit
- dos5_busy:
- MOV ax, 200h ; No error, busy.
- dos5_exit:
- ret
-
- dosfn5 endp
-
- ;-------- dos function #6: input status --------------------------
- ; Returns "busy" if no characters waiting to be read.
- dosfn6 proc near
- call peekchar
- mov ax, 200h ; No error, busy.
- jz dos6_exit
- xor ax, ax ; No error, not busy.
- dos6_exit:
- ret
- dosfn6 endp
-
- ;-------- dos function #7: flush input buffer --------------------
- ; Clears the IBM keyboard input buffer. Since it is a circular
- ; queue, we can do this without knowing the beginning and end
- ; of the buffer; all we need to do is set the tail of the queue
- ; equal to the head (as if we had read the entire queue contents).
- ; Also resets all the device driver's stuffahead buffers.
- dosfn7 proc near
- xor ax, ax
- mov fnkey.len, ax ; Reset the stuffahead buffers.
- mov cprseq.len, ax
- mov brkkey.len, ax
- mov xlatseq.len, ax
- mov idseq.len, ax ; CRH 3-9-90
-
- mov ax, abs40
- mov es, ax
- mov ax, es:buffer_head ; clear queue by making the tail
- mov es:buffer_tail, ax ; equal to the head
-
- xor ax, ax ; no error, not busy.
- ret
- dosfn7 endp
-
- page
- if takeBIOS
- ;--- new_vid_bios -------------------------------------------
- ; New_vid_bios simply replaces the write_tty call.
- ; All other calls get sent to the old video bios.
- ; This gives BIOS ANSI capability.
- ; However, it takes away the escape character.
- ; If this is not desired, just tell init to not take over the vector.
-
- new_vid_bios proc
- cmp ah, 14
- jz nvb_write_tty
- jmp dword ptr cs:old_vid_bios
- nvb_write_tty:
- push cx
- mov cl, cs:cur_attrib
- ; If in graphics mode, BL is new color
- call in_g_mode ; returns carry set if text mode
- jc nvb_wt_text
- mov cs:cur_attrib, bl ; ja?
- nvb_wt_text:
- int 29h ; write AL
- mov cs:cur_attrib, cl ; restore color
- pop cx
- iret
-
- new_vid_bios endp
- endif
-
- ;------ int_29 ----------------------------------------------
- ; Int 29 handles DOS quick-access putchar.
- ; Last device loaded with attribute bit 4 set gets accessed for
- ; single-character writes via int 29h instead of via interrupt.
- ; Must preserve all registers.
- ; Installed as int 29h by dosfn0 (init).
- int_29_buf db ?
-
- int_29 proc near
- sti
- push ds
- push es
- push_all
- mov cx, 1
- mov bx, cs
- mov es, bx
- mov ds, bx
- mov si, offset int_29_buf
- mov byte ptr [si], al
- call dosfn8
- pop_all
- pop es
- pop ds
- iret
- int_29 endp
-
- page
- ;------ dosfn8 -------------------------------------------------------
- ; Handles writes to the device (with or without verify).
- ; Called with
- ; CX = number of bytes to write
- ; ES:SI = transfer buffer
- ; DS = CS, so we can access local variables.
-
- dosfn8 proc near
-
- mov f_cptr_seg, es ; save segment of char ptr
-
- ; Read the BIOS buffer address/cursor position variables.
- mov ax, abs40
- mov ds, ax
- assume ds:abs40
-
- ; Find current video mode and screen size.
- mov ax,word ptr crt_mode ; al = crt mode; ah = # of columns
- mov cs:video_mode, al
- dec ah ; ah = max column
- mov cs:max_x, ah
-
- ; Find current cursor coordinates.
- mov al,active_page
- cbw
- add ax,ax
- xchg bx,ax
- mov ax,cursor_posn[bx]
- mov cs:cur_coords,AX
-
- ; Find video buffer segment address; adjust it
- ; so the offset is zero; return in AX.
-
- ; DS is abs40.
- ; Find 6845 address.
- mov ax, addr_6845
- mov cs:port_6845, ax
- ; Find video buffer address.
- MOV AX,crt_start
- shr ax, 1
- shr ax, 1
- shr ax, 1
- shr ax, 1
- add ah, 0B0h ; assume it's a monochrome card...
- CMP cs:video_mode,07
- jz d8_gots
- add ah, 8 ; but if not mode 7, it's color.
- mov snow_flag,1 ; [REN] set to remove CGA snow
- mov pseudo_flag,0 ; [REN] and graphics pseudo-cursor
- d8_gots:
- push cs
- pop ds
- assume ds:code
- mov video_seg, ax
- mov es, ax
- call xy_to_regs ; Set DX, DI according to cur_coords.
-
- ; | If in graphics mode, clear old pseudocursor
- call in_g_mode
- jc d8_no_cp
- call pseudocursor ; write block in xor
- d8_no_cp:
- mov bx, xlate_tab_ptr ; get pointer to translation table
-
- mov ah, cur_attrib
- mov ds, f_cptr_seg ; get segment of char ptr
- assume ds:nothing
- cld ; make sure we'll increment
-
- ; The Inner Loop: 4+12 +4+4 +4+4 +0+15 +4+4 +4+18 = 77 cycles/loop
- ; on 8088; at 4.77 MHz, that gives 16.1 microseconds/loop.
- ; At that speed, it takes 32 milliseconds to fill a screen.
-
- ; Get a character, put it on the screen, repeat 'til end of line
- ; or no more characters.
- jcxz f_loopdone ; if count = 0, we're already done.
- cmp cs:escvector, 0 ; If in middle of an escape sequence,
- jnz f_in_escapex ; jump to escape sequence handler.
-
- f_tloop:; | If in graphics mode, jump to alternate loop
- ; | What a massive kludge! A better approach would have been
- ; | to collect characters for a "write n chars" routine
- ; | which would handle both text and graphics modes.
- call in_g_mode
- jc f_t_modetest
- jmp f_g_cloop
-
- f_in_escapex:
- jmp f_in_escape
-
- ;--- snow mode code
- f_t_modetest:
- test cs:snow_flag, 1
- jnz f_t_cgaloop
- ;--- End of snow mode code
-
- f_t_cloop:
- LODSB ; get char! (al = ds:[si++])
- test al, al ; skip nulls hyc 31 Oct 90
- jnz f_t_cloop1 ; ditto
- loop f_t_cloop ; ditto
- jmp short f_loopdone ; ditto
- f_t_cloop1:
- cmp al, 28 ; is it a control char?
- jb f_control ; maybe...
- f_t_nctl:
- seg_cs
- xlat
- STOSW ; Put Char! (es:[di++] = ax)
- dec dx ; count down to end of line
- loopnz f_t_cloop ; and go back for more.
- jz f_t_at_eol ; at end of line; maybe do a crlf.
- jmp short f_loopdone
-
- ;--- snow mode code ---
- ; Alternate main loop for snowy text cards.
- f_t_cgaloop:
- LODSB ; get char! (al = ds:[si++])
- test al, al ; skip nulls hyc 31 Oct 90
- jnz f_t_cgal1
- loop f_t_cgaloop
- jmp short f_loopdone
- f_t_cgal1:
- cmp al, 28 ; is it a control char?
- jb f_control ; maybe...
- f_t_cganctl:
- seg_cs
- xlat
-
- ; Wait for horizontal or vertical retrace.
- push dx
- xchg ax, bp ; save AX in BP during wait
- mov dx, 03dah ; access CGA status register
- f_t_cga1wait: in al, dx
- test al, 1 ; wait until end of horizontal
- jnz f_t_cga1wait ; blanking...
- f_t_cga2wait: in al, dx
- test al, 9 ; then wait for start of blanking...
- jz f_t_cga2wait
- xchg ax, bp ; very, very quickly recover AX
-
- STOSW ; Put Char! (es:[di++] = ax)
- pop dx
-
- dec dx ; count down to end of line
- loopnz f_t_cgaloop ; and go back for more.
- jz f_t_at_eol ; at end of line; maybe do a crlf.
- jmp short f_loopdone
- ;--- end of snow mode code ---
-
- f_looploop:
- f_ansi_exit: ; in case we switched into
- loopnz f_tloop ; a graphics mode
- f_t_at_eol:
- jz f_at_eol
-
- f_loopdone:
-
- ;--------- All done with write request -----------
- ; DI is cursor address; cursor position in cur_y, dl.
- mov ax, cs
- mov ds, ax ; get our segment back
- assume ds:code
-
- ; Restore cur_x = max_x - dx + 1.
- mov al, max_x
- inc al
- sub al, dl
- mov cur_x, al
- ; Set cursor position; cursor adr in DI; cursor pos in cur_x,cur_y
- call set_pseudocursor
- ; Return to DOS.
- xor ax, ax ; No error, not busy.
- ret
-
- ;---- handle control characters ----
- ; Note: cur_x is not kept updated in memory, but can be
- ; computed from max_x and dx.
- ; Cur_y is kept updated in memory.
- f_control:
- cmp al, 27 ; Is it an escape?
- jz f_escapex
- cmp al, 13 ; carriage return?
- jz f_cr
- cmp al, 10 ; line feed?
- jz f_lf
- cmp al, 9 ; tab?
- jz f_tabx
- cmp al, 8 ; backspace?
- jz f_bs
- cmp al, 7 ; bell?
- jz f_bell
- jmp f_nctl ; then it is not a control char.
-
- f_tabx: jmp f_tab
- f_escapex:
- jmp f_escape
-
- f_bs: ;----- Handle backspace -----------------
- ; Moves cursor back one space without erasing. No wraparound.
- cmp dl, cs:max_x ; wrap around to previous line?
- ja fbs_wrap ; yep; disallow it.
- dec di ; back up one char & attrib,
- dec di
- inc dx ; and note one more char left on line.
- fbs_wrap:
- jmp f_looploop
-
- f_bell: ;----- Handle bell ----------------------
- ; Use BIOS to do the beep. DX is not changed, as bell is nonprinting.
- call beep
- or al, al ; clear z
- ; old (more portable) version:
- ; mov ax, 0e07h ; "write bell to tty simulator"
- ; mov bx, 0 ; "page zero, color black"
- ; int 10h ; call BIOS
- ; mov ah, cs:cur_attrib ; restore current attribute
- ; mov bx, cs:xlate_tab_ptr ; restore translate table address
- ; or al, al ; al still 7; this clears Z.
- jmp f_looploop ; Let main loop decrement cx.
-
- f_cr: ;----- Handle carriage return -----------
- ; di -= cur_x<<1; set di= address of start of line
- ; dx=max_x+1; set bx= chars left in line
- mov al, cs:max_x
- inc al
- sub al, dl ; Get cur_x into ax.
- mov ah, 0
- sub di, ax
- sub di, ax
- mov dl, cs:max_x ; Full line ahead of us.
- inc dx
- mov ah, cs:cur_attrib ; restore current attribute
- or al, 1 ; clear z
- jmp f_looploop ; and let main loop decrement cx
-
- f_at_eol:
- ;----- Handle overrunning right end of screen -------
- ; cx++; compensate for double loop
- ; if (!wrap_flag) { dx++; di-=2; }
- ; else do_crlf;
- inc cx
- test cs:wrap_flag, 1
- jnz feol_wrap
- dec di
- dec di
- inc dx
- jmp f_looploop
- feol_wrap:
- ; dx=max_x+1; set bx= chars left in line
- ; di -= 2*(max_x+1);
- ; do_lf
- mov dl, cs:max_x
- inc dx
- sub di, dx
- sub di, dx
- ; fall thru to line feed routine
-
- f_lf: ;----- Handle line feed -----------------
- ; if (cur_y >= sr_max_y) scroll; scroll screen up if needed
- ; else { cur_y++; di += max_x<<1; else increment Y
-
- mov al, cs:sr_max_y
- cmp cs:cur_y, al
- jb flf_noscroll
- call scroll_up ; preserves bx,cx,dx,si,di
- jmp short flf_done
- flf_noscroll:
- inc cs:cur_y
- mov al, cs:max_x
- mov ah, 0
- inc ax
- add ax, ax
- add di, ax
- flf_done:
- mov ah, cs:cur_attrib ; restore current attribute
- or al, 1 ; clear z
- jmp f_looploop ; and let main loop decrement cx
-
- f_tab: ;----- Handle tab expansion -------------
- ; Get cur_x into al.
- mov al, cs:max_x
- inc al
- sub al, dl
- ; Calculate number of spaces to output.
- push cx ; save cx
- mov ch, 0
- mov cl, al ; get zero based x coordinate
- and cl, 7
- neg cl
- add cl, 8 ; 0 -> 8, 1 -> 8, ... 7 -> 1
- sub dx, cx ; update chars-to-eol, maybe set z
- pushf ; || save Z for main loop
- ; ah is still current attribute. Move CX spaces to the screen.
- ;
- ; mods to create version with non destructive tab. CRH 23 FEB 90
- ; mov al, '=' ;xxxx
- call in_g_mode ; | graphics mode
- jnc f_tab_putc ; |
- ; call snow_stosw ; Carefully do a REP STOSW.
- ntl: ; added for non-destructive TAB
- inc di ; added for non-destructive TAB
- inc di ; added for non-destructive TAB
- loop ntl ; added for non-destructive TAB
- popf ; || restore Z flag for main loop test
- pop cx ; restore cx
- jmp f_looploop ; Let main loop decrement cx.
-
- ;--------------- graphics mode support -----------------------
-
- f_tab_putc: ; graphics mode- call putc to put the char
- add dx, cx ; move back to start of tab
- f_tp_lp:
- ;
- ; mod to create version with non destructive tab. CRH 23 FEB 90
- ; call putchar
- dec dx ; go to next cursor position
- loop f_tp_lp
- popf ; Z set if wrapped around EOL
- pop cx
- jmp f_looploop
-
- ;--- snow_stosw -----------------------------------------------
- ; Useful for tab expansion and insert/delete character.
- ; Preserves all registers except BP and CX.
-
- snow_stosw proc near
- test cs:snow_flag, 1 ; wait for retrace?
- jnz snos_snow
- REP STOSW
- ret
- snos_snow:
- push dx
- mov dx, 03dah ; access CGA status register
- snos_loop: xchg ax, bp ; save AX in BP during wait
- snos_cga1wait: in al, dx
- test al, 1 ; wait until end of horizontal
- jnz snos_cga1wait ; blanking...
- snos_cga2wait: in al, dx
- test al, 9 ; wait for start of blanking...
- jz snos_cga2wait
- xchg ax, bp ; very, very quickly recover AX
- stosw
- loop snos_loop
- pop dx
- ret
- snow_stosw endp
-
- ;--- snow_movsw -----------------------------------------------
- ; Useful for insert/delete character.
- ; Preserves all registers except AX and CX.
- ; Still snows a little near the left edge on a 4.77 MHz 8088;
- ; probably doesn't snow on an 80286.
-
- snow_movsw proc near
- test cs:snow_flag, 1 ; wait for retrace?
- jnz snom_snow
- rep movsw
- ret
- snom_snow:
- push dx
- mov dx, 03dah ; access CGA status register
- snom_loop:
- snom_cga1wait: in al, dx
- test al, 1 ; wait until end of horizontal
- jnz snom_cga1wait ; blanking...
- snom_cga2wait: in al, dx
- test al, 9 ; wait for start of blanking...
- jz snom_cga2wait
- movsw ; Even this is too slow- but who cares.
- loop snom_loop
- pop dx
- ret
- snow_movsw endp
-
- ;---- in_g_mode -------------
- ; Returns Carry set if not in a graphics mode.
- ; Preserves all registers.
-
- in_g_mode proc near
- cmp cs:video_mode, 4
- jb igm_stc
- cmp cs:video_mode, 7
- jz igm_stc
- clc
- ret
- igm_stc:
- stc
- ret
- in_g_mode endp
-
- ;---- Where to go when a character turns out not to be special
- f_nctl:
- f_not_ansi:
- call in_g_mode
- jnc f_g_nctl ; graphics mode
- f_jmptnctl:
- ; | Snow Mode Code
- test cs:snow_flag, 1
- jz f_jnctl ;[REN] - was "jnz"
- jmp f_t_cganctl
- f_jnctl:
- ; | End of Snow Mode Code
- jmp f_t_nctl ; text mode
-
- ;---- Alternate main loop for graphics mode ----
- f_g_cloop:
- LODSB ; get char! (al = ds:[si++])
- test al, al ; skip nulls hyc 31 Oct 90
- jnz f_g_cloop1 ; ditto
- loop f_g_cloop ; ditto
- jmp f_loopdone ; ditto
- f_g_cloop1:
- cmp al, 28 ; is it a control char?
- jb f_g_control ; maybe...
- f_g_nctl:
- seg_cs
- xlat
- call putchar
- dec dx ; count down to end of line
- loopnz f_g_cloop ; and go back for more.
- jz f_g_at_eol ; at end of line; maybe do a crlf.
- jmp f_loopdone
-
- f_g_control: jmp f_control
- f_g_at_eol: jmp f_at_eol
-
- ;---- putchar ------------------------------------------------
- ; Writes char AL, attribute AH to screen at (max_x+1-dl), cur_y.
- ; On entry, registers set up as per xy_to_regs.
- ; Preserves all registers.
- putchar proc near
- push dx
- push cx
- push bx
- push ax
- ; 1. Set cursor position.
- mov al, cs:max_x
- inc al
- sub al, dl
- mov cs:cur_x, al
- mov dx, cs:cur_coords ; get X & Y into DX
- xor bx, bx ; choose dpy page 0
- mov ah, 2 ; chose "Set Cursor Position"
- int 10h ; call ROM BIOS
- ; 2. Write char & attribute.
- mov cx, 1
- pop ax ; get char in AL
- push ax
- mov bl, ah ; attribute in BL
- mov bh, 0
- mov ah, 9
- int 10h
- pop ax
- pop bx
- pop cx
- pop dx
- ret
- putchar endp
-
- ;---- set_pseudocursor ------------
- ; If in graphics mode, set pseudocursor, else set real cursor.
- ; Destroys DS!!!!
- ; 8/10/86 drk Fixed multiple display page code
-
- set_pseudocursor proc near
- call in_g_mode
- jnc pseudocursor
- ; old (more portable, but slower) version
- ; mov dx, cur_coords ; get X & Y into DX
- ; xor bx, bx ; choose dpy page 0 (not right)
- ; mov ah, 2 ; chose "Set Cursor Position"
- ; int 10h ; call ROM BIOS
-
- ; Write directly to 6845 cursor address register.
- mov bx, di
- assume ds:abs40
- mov ax, abs40
- mov ds, ax
- add bx, crt_start ; In case not display page 0.
- shr bx, 1 ; Convert word index to byte index.
-
- mov dx, port_6845
- mov al, 0eh
- out dx, al
-
- jmp $+2
- inc dx
- mov al, bh
- out dx, al
-
- jmp $+2
- dec dx
- mov al, 0fh
- out dx, al
-
- jmp $+2
- inc dx
- mov al, bl
- out dx, al
-
- ; Set cursor position in low memory.
- ; Does anybody ever use anything but page zero?
- mov al,active_page
- cbw
- add ax,ax
- xchg bx,ax
- mov ax, cs:cur_coords
- mov cursor_posn[bx],ax
- ret
-
- assume ds:code
- set_pseudocursor endp
-
-
- ;---- pseudocursor --------------------------------------------------
- ; If pseudo_flag is true, writes a color 15 block in XOR at the
- ; current cursor location, and sets cursor position.
- ; Otherwise, just sets cursor position.
- ; Preserves DS, ES, BX, CX, DX, SI, DI.
-
- pseudocursor proc near
- test pseudo_flag, 1
- jz psc_setpos
- mov ax, 8f16h ; xor, color 15, ^V (small block)
- call putchar
- jmp short psc_ret
-
- psc_setpos:
- push dx
- push bx
- push ax
-
- mov dx, cur_coords ; get X & Y into DX
-
- push ds
- mov ax, abs40
- mov ds, ax
- assume ds:abs40
- mov bh, active_page ; supposed to be zero in graph modes?
- pop ds
- assume ds:code
- mov ah, 2 ; chose "Set Cursor Position"
- int 10h ; call ROM BIOS
-
- pop ax
- pop bx
- pop dx
-
- psc_ret:
- ret
-
- pseudocursor endp
-
- ;--------------- end of graphics mode support --------------------
-
- dosfn8 endp
-
- ;--- get_blank_attrib ------------------------------------------------
- ; Determine new attribute and character for a new blank region.
- ; Use current attribute, just disallow blink and underline.
- ; (Pretty strange way to do it. Might want to disallow rev vid, too.)
- ; Returns result in AH, preserves all other registers.
- get_blank_attrib proc near
- mov ah, 0
- call in_g_mode
- jnc gb_aok ; if graphics mode, 0 is bkgnd
-
- mov ah, cs:cur_attrib
- and ah, 7fh ; disallow blink
- cmp cs:video_mode, 7 ; monochrome?
- jnz gb_aok
- cmp ah, 1 ; underline?
- jnz gb_aok
- mov ah, 7 ; yep- set it to normal.
- gb_aok: ret
- get_blank_attrib endp
-
-
- ;---- scroll_up ---------------------------------------------------
- ; Scroll screen up- preserves ax, bx, cx, dx, si, di, ds, es.
- ; Moves screen up 1 line, fills the last line with blanks.
- ; Attribute of blanks is the current attribute sans blink and underline.
-
- scroll_up proc near
- push ax
- push bx
- push cx
- push dx
-
- call get_blank_attrib
- mov bh, ah ; color to use on new blank areas
- mov al, 1 ; AL is number of lines to scroll.
- mov ah, 6 ; BIOS: scroll up
- mov cl, 0 ; upper-left-x of data to scroll
- mov ch, cs:sr_min_y ; upper-left-y of data to scroll
- mov dl, cs:max_x ; lower-rite-x
- mov dh, cs:sr_max_y ; lower-rite-y (zero based)
- int 10h ; call BIOS to scroll a rectangle.
-
- pop dx
- pop cx
- pop bx
- pop ax
- ret
- scroll_up endp
-
- ;---- lookup -----------------------------------------------
- ; Called by getchar, peekchar, and key to see if a given key has
- ; been redefined.
- ; Sets AH to zero if AL is not zero (i.e. if AX is not a function key).
- ; Returns with Z cleared if no redefinition; otherwise,
- ; Z is set, SI points to redefinition string, CX is its length.
- ; Preseves AL, all but CX and SI.
- ; Redefinition table organization:
- ; Strings are stored in reversed order, first char last.
- ; The word following the string is the character to be replaced;
- ; the next word is the length of the string sans header.
- ; param_end points to the last byte used by the parameter buffer;
- ; redef_end points to the last word used by the redef table.
-
- lookup proc near
- mov si, redef_end ; Start at end of table, move down.
- or al, al
- jz lu_lp
- mov ah, 0 ; clear extraneous scan code
- lu_lp: cmp si, param_end
- jbe lu_notfound ; If below redef table, exit.
- mov cx, [si]
- cmp ax, [si-2] ; are you my mommy?
- jz lu_gotit
- sub si, 4
- sub si, cx ; point to next header
- jmp lu_lp
- lu_notfound:
- or si, si ; clear Z
- jmp short lu_exit
- lu_gotit:
- sub si, 2
- sub si, cx ; point to lowest char in memory
- cmp al, al ; set Z
- lu_exit:
- ret
- lookup endp
-
- ;---- searchbuf --------------------------------------------
- ; Called by getchar and peekchar to see if any characters are
- ; waiting to be gotten from sources other than BIOS.
- ; Returns with Z set if no chars found, BX=keybuf & SI=keybuf.len otherwise.
- searchbuf proc near
- ; Search the stuffahead buffers.
- ; mov cx, 4 ; number of buffers to check for chars
- mov cx, 5 ; CRH 3-9-90
- mov bx, offset fnkey - 4
- sbloop: add bx, 4 ; point to next buffer record
- mov si, [bx].len
- or si, si ; empty?
- loopz sbloop ; if so, loop.
- ret
- searchbuf endp
-
- ;---- getchar -----------------------------------------------
- ; Returns AL = next char.
- ; Trashes AX, BX, CX, BP, SI.
- getchar proc near
- gc_searchbuf:
- ; See if any chars are waiting in stuffahead buffers.
- call searchbuf
- jz gc_trykbd ; No chars? Try the keyboard.
- ; A nonempty buffer was found.
- dec [bx].len
- dec si
- mov bp, [bx].adr ; get pointer to string
- mov al, byte ptr ds:[bp][si]; get the char
- ; Recognize function key sequences, move them to highest priority
- ; queue.
- sub si, 1 ; set carry if si=0
- jc gc_nofnkey ; no chars left -> nothing to protect.
- cmp bx, offset fnkey
- jz gc_nofnkey ; already highest priority -> done.
- or al, al
- jnz gc_nofnkey ; nonzero first byte -> not fnkey.
- ; Found a function key; move it to highest priority queue.
- dec [bx].len
- mov ah, byte ptr ds:[bp][si]; get the second byte of fn key code
- gc_fnkey:
- mov fnkey.len, 1
- mov fnkeybuf, ah ; save it.
- gc_nofnkey:
- ; Valid char in AL. Return with it.
- jmp short gcdone
-
- gc_trykbd:
- ; Actually get a character from the keyboard.
- mov ah, 0
- int 16h ; BIOS returns with char in AX
- ; If it's Ctrl-break, it has already been taken care of.
- or ax, ax
- jz gc_trykbd
-
- ; Look in the reassignment table to see if it needs translation.
- call lookup ; Z=found; CX=length; SI=ptr
- jnz gc_noredef
- ; Okay; set up the reassignment, and run thru the translation code.
- mov xlatseq.len, cx
- mov xlatseq.adr, si
- jmp gc_searchbuf
- gc_noredef:
- ; Is it a function key?
- cmp al, 0
- jz gc_fnkey ; yep- special treatment.
- gcdone: ret ; with character in AL.
-
- getchar endp
-
- ;---- peekchar -----------------------------------------------
- ; Returns Z if no character ready, AL=char otherwise.
- ; Trashes AX, BX, CX, BP, SI.
- peekchar proc near
- pc_searchbuf:
- call searchbuf
- jz pc_trykbd ; No chars? Try the keyboard.
- ; A nonempty buffer was found.
- dec si
- mov bp, [bx].adr ; get pointer to string
- mov al, byte ptr ds:[bp][si]; get the char
- ; Valid char from buffer in AL. Return with it.
- jmp short pcdone
- pc_trykbd:
- ; Actually peek at the keyboard.
- mov ah, 1
- int 16h ; BIOS returns with char in AX
- jz pcexit
- ; If it's control-break, it's already been taken care of.
- or ax, ax
- jnz pc_notbrk
- mov ah, 0
- int 16h ; so get rid of it!
- jmp short pc_trykbd
- pc_notbrk:
- ; Look in the reassignment table to see if it needs translation.
- call lookup ; Z=found; CX=length; SI=ptr
- jnz pcdone ; Nope; just return the char.
- ; Okay; get the first code to be returned.
- add si, cx
- mov al, [si-1]
- pcdone: or ah, 1 ; NZ; char ready!
- pcexit: ret ; with character in AL, Z true if no char waiting.
- peekchar endp
-
- ;---- beep ------------------------------------------------------
- ; Beep speaker; period given by beep_div, duration by beep_len.
- ; Preserves all registers.
-
- beep_div dw 1300 ; fairly close to IBM beep
- beep_len dw 2 ; [REN] 2/18 sec- shorter than IBM
-
- beep proc near
- push_all
-
- mov al, 10110110b ; select 8253
- mov dx, 43h ; control port address
- out dx, al
- dec dx ; timer 2 address
- mov ax, cs:beep_div
- jmp $+2
- out dx, al ; low byte of divisor
- xchg ah, al
- jmp $+2
- out dx, al ; high byte of divisor
- mov dx, 61h
- jmp $+2
- in al, dx ; get current value of control bits
- push ax
- or al, 3
- jmp $+2
- out dx, al ; turn speaker on
-
- ; Wait for desired duration by monitoring time-of-day 18 Hz clock
- push es
- mov ax, abs40
- mov es, ax
- assume es:abs40
- mov bx, timer_low
- add bx, cs:beep_len
- mov cx, -1 ; emergency, in case clock dead
- beeplp: mov ax, timer_low
- cmp ax, bx
- jg beepover
- loop beeplp
- beepover:
- pop es
- assume es:code
-
- ; Turn off speaker
- pop ax
- and al, not 3 ; turn speaker off
- out dx, al
- pop_all
- ret
- beep endp
-
- CODE ends
-
- end ; of nansi.asm
-