;----- zansi_f.asm --------------------------------------------- ; Zephyr ANSI terminal driver. ; Copyright (C) 1986, Thomas Hanlin III, Springfield VA. ; Based on original code for NANSI by Daniel Kegel, Pasadena, CA. ;------------------------------------------------------------------------ ; Each routine is called with the following register usage: ; AX = max(1, value of first parameter) ; Z flag is set if first parameter is zero. ; CX = number of paramters ; SI = offset of second parameter from CS ; DS = CS ; ES:DI points to the current location on the memory-mapped screen. ; DX is number of characters remaining on the current screen line. ; The control routine is free to trash AX, BX, CX, SI, and DS. ; It must preserve ES, and can alter DX and DI if it wants to move the ; cursor. ;---------------------------------------------------------------- ; To zansi_p.asm public ansi_fn_table ; From zansi.asm extrn port_6845:word extrn cur_coords:word, saved_coords:word extrn cur_x:byte, max_x:byte extrn cur_y:byte, max_y:byte extrn cur_attrib:byte, wrap_flag:byte extrn xy_to_regs:near extrn get_blank_attrib:near extrn cpr_esc:byte, cprseq:word extrn video_mode:byte extrn lookup:near ; from zansi_p.asm extrn param_buffer:word ; used in keyboard programming extrn param_end:word extrn redef_end:word keybuf struc ; used in making cpr sequence 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 ? crt_palette db ? ABS40 ends code segment byte public 'CODE' assume cs:code, ds:code ;----- byteout --------------------------------------------------- ; Converts al to a decimal ASCII string (in 0..99), ; stores it at ES:DI++. Returns DI pointing at byte after last digit. ; Destroys DL. byteout proc near aam add ax, 3030h xchg ah, al stosb xchg ah, al stosb ret byteout endp ;----- ansi_fn_table ----------------------------------- ; Table of offsets of terminal control subroutines in order of ; the character that invokes them, @..Z, a..z. Exactly 53 entries. ; All the subroutines are defined below in this module. ansi_fn_table label word dw ic, cup, cdn, cfw, cbk ; @, A, B, C, D dw nul, nul, nul, hvp, nul ; E, F, G, H, I dw eid, eil, il, d_l, nul ; J, K, L, M, N dw nul, dc, nul, nul, nul ; O, P, Q, R, S dw nul, nul, nul, nul, nul ; T, U, V, W, X dw nul, nul ; Y, Z dw nul, nul, nul, nul, nul ; a, b, c, d, e dw hvp, nul, sm, nul, nul ; f, g, h, i, j dw nul, rm, sgr, dsr, nul ; k, l, m, n, o dw key, nul, nul, scp, nul ; p, q, r, s, t dw rcp, nul, nul, nul, nul ; u, v, w, x, y dw nul ; z ansi_functions proc near ; set return type to NEAR ;----- nul --------------------------------------------- ; No-action ansi sequence; called when unknown command given. nul: ret ;----- Cursor Motion ----------------------------------------------- ;-- cursor to y,x hvp: or al,al ; First parameter is desired Y coordinate. jz hvp_yok dec ax ; Convert to zero-based coordinates. hvp_yok:mov cur_y,al ; Get second parameter, if it is there, and set X with it. xor ax,ax cmp cx,2 ; was there a second parameter? jb hvp_xok lodsb ; yes. or al,al jz hvp_xok dec ax ; convert to zero-based coordinates. hvp_xok:mov cur_x,al ; Clip to maximum coordinates. hvp_set: mov ax, cur_coords ; al = x, ah = y cmp al, max_x jbe hvp_sxok mov al, max_x mov cur_x, al hvp_sxok: cmp ah, max_y jbe hvp_syok mov al, max_y mov cur_y, al hvp_syok: ; Set values of DX and DI accordingly. call xy_to_regs ret ;-- cursor forward -- cfw: add cur_x, al jmp hvp_set ;-- cursor back ----- cbk: sub cur_x, al jae cbk_ok mov cur_x, 0 cbk_ok: jmp hvp_set ;-- cursor down ----- cdn: add cur_y, al jmp hvp_set ;-- cursor up ------- cup: sub cur_y, al jae cup_ok mov cur_y, 0 cup_ok: jmp hvp_set ;-- save cursor position -------------------------------------- scp: mov ax, cur_coords mov saved_coords, ax ret ;-- restore cursor position ----------------------------------- rcp: mov ax, saved_coords mov cur_coords, ax jmp hvp_set ; Clip in case we have switched video modes. ;-- set graphics rendition ------------------------------------ ; Modifies the color in which new characters are written. sgr: dec si ; get back pointer to first parameter or cx, cx ; Did he give any parameters? jnz sgr_loop mov [si],cl ; no parameters, so fake inc cx ; one with the default value. sgr_loop: ; Handles each parameter lodsb ; al = next parameter push cx mov cx,colors mov bx,offset color_table -3 sgr_search: add bx,3 cmp al,[bx] loopne sgr_search ; until match found or done jne sgr_loopx ; If parameter named a known color, set the current color variable. mov bx,1[bx] mov al,cur_attrib and al,bl or al,bh mov cur_attrib,al sgr_loopx: pop cx loop sgr_loop ; until no more parameters. ret ;-- erase in line ---------------------------------------- ; Uses BIOS to scroll away a one-line rectangle eil: push dx mov cx, cur_coords mov dh, ch jmp short scrollem ;-- erase in display ------------------------------------- ; Uses BIOS to scroll away all of display eid: cmp al,2 jnz eid_ignore ; param must be two xor cx,cx mov cur_coords,cx call xy_to_regs ; doesn't modify CX push dx mov dh,max_y scrollem: call get_blank_attrib mov bh,ah mov dl,max_x mov ax,600h int 10h pop dx eid_ignore: ret ;-- device status report -------------------------------- ; Stuffs an escape, a left bracket, current Y, semicolon, current X, ; a capital R, and a carriage return into input stream. ; The coordinates are 1 to 3 decimal digits each. dsr: push di push dx push es mov ax,cs mov es,ax std ; Store string in reversed order for fun mov di,offset cpr_esc - 2 mov al,cur_y inc al ; convert to one-based coords call byteout ; row mov al,';' stosb mov al,cur_x inc al ; convert to one-based coords call byteout ; column mov al,'R' ; R ANSI function 'Cursor Position Report' stosb mov al,13 mov word ptr cprseq.adr, di ; save pointer to last char in string stosb ; send a carriage return, too mov ax,offset cpr_esc sub ax,di ; ax is # of characters in string mov word ptr cprseq.len,ax ; pass info to the getchar routine cld pop es pop dx pop di ret ;-- keyboard reassignment ------------------------------- ; Key reassignment buffer is between param_end and redef_end+2, exclusive. ; When it shrinks or grows, param_end is moved. ; Format of an entry is as follows: ; highest address -> length:word (may be 0) ; key to replace:word (either hi or low byte is zero) ; . ; . new key value, "length" bytes long ; . ; lowest address -> next entry, or free space. ; If no arguments are given, keyboard is reset to default condition. ; Otherwise, first parameter (or first two, if first is zero) defines ; the key whose value is to be changed, and the following parameters ; define the key's new, possibly zero-length, value. key: ; Is this a reset? jcxz key_init ; Get the first (or first two) parameters cld dec si ; point to first param dec cx ; Assume it's a fn key, get two params dec cx lodsw or al, al ; Is it a function key? jz key_fnkey inc cx ; It's not a function key- put second param back dec si key_fnkey: ; Key to redefine now in AX. If it's already redefined, ; lookup will set Z, point SI to redef string, set CX to its length. push di push es push cx push si std ; moving up, must move from top down push ds pop es ; string move must have ES=DS call lookup ; rets Z if redefined... jnz key_newkey ; It's already defined. Erase its old definition- i.e., move ; region param_end+1..SI-1 upwards CX+4 bytes, add CX+4 to param_end. add cx, 4 mov bp, param_end ; save old value in bp... add param_end, cx dec si ; start at (SI-1) mov di, si add di, cx ; move to (start + CX+4) mov cx, si sub cx, bp ; length of region old_param_end+1..start rep movsb key_newkey: ; Key not redefined. See if there's enough room to redefine it. pop si ; get back pointer to redef string pop cx ; get back number of bytes in redef string mov di, param_end ; hi byte of new redef record, hi byte of len sub di, 4 ; hi byte of new data field mov bx, di sub bx, cx ; hi byte of remaining buffer space sub bx, 16 ; better be at least 16 bytes room cmp bx, param_buffer jb key_popem ; nope- forget it. ; Nothing in the way now! mov [di+3], cx ; save length field mov [di+1], ax ; save name field jcxz key_nullstring key_saveloop: ; save data field movsb add si, 2 ; input string ascending, output descending loop key_saveloop key_nullstring: mov param_end, di ; save adr of new hi byte of free area key_popem: pop es pop di key_exit: cld ret key_init: ; Build the default redefinition table: ; control-printscreen -> control-P push es push ds pop es std mov di, redef_end mov ax, 1 stosw mov ax, 7200h ; control-printscreen stosw mov al, 16 ; control P stosb mov param_end, di ; save new bottom of redef table pop es jmp key_exit ;---- Delete/Insert Lines ------------------------------- ; AL is number of lines to delete/insert. ; Preserves DX, DI; does not move cursor. d_l: ; Delete lines. mov ah, 6 ; BIOS: scroll up jmp short il_open il: ; Insert lines. mov ah, 7 ; BIOS: scroll down il_open: ; Whether inserting or deleting, limit him to (max_y - cur_y) lines; ; if above that, we're just clearing; set AL=0 so BIOS doesn't burp. mov bh, max_y sub bh, cur_y cmp al, bh jbe il_ok ; DRK 9/4... xor al,al ; he tried to move too far il_ok: push ax call get_blank_attrib mov bh, ah ; color to use on new blank areas pop ax ; AL is number of lines to scroll. xor cl,cl ; upper-left-x of data to scroll mov ch, cur_y ; upper-left-y of data to scroll push dx mov dl, max_x ; lower-right-x mov dh, max_y ; lower-right-y (zero based) int 10h ; call BIOS to scroll a rectangle. pop dx ret ; done. ;-- Insert / Delete Characters ---------------------------- ; AL is number of characters to insert or delete. ; Preserves DX, DI; does not move cursor. ic: mov ch, 1 ; 1 => swap dest & source below jmp short dc_ch dc: xor cl,cl dc_ch: cmp cs:video_mode, 4 jb DC_CH_DO cmp cs:video_mode, 7 jnz dc_ret ; | if in graphics mode, ignore. DC_CH_DO: ; AL = number of chars to ins or del (guarenteed nonzero). ; Limit him to # of chars left on line. cmp al, dl jbe dc_cok mov al, dl dc_cok: push di ; DI is current address of cursor xchg ax, cx ; CX gets # of chars to ins/del mov bp, cx ; BP gets # of columns to clear. ; Set up source = destination + cx*2, count = dx - cx xor ch,ch ; make it a word mov si, di add si, cx add si, cx neg cl add cl, dl xor ch,ch ; CX = # of words to transfer cld ; REP increments si & di ; If this is an insert, then flip transfer around in both ways. test ah, 1 jz dc_noswap xchg di,si ; source <-> dest std ; up <-> down mov ax,cx ; make move over same range dec ax shl ax,1 ; AX=dist from 1st to last byte. add di,ax ; Start transfer at high end of block add si,ax ; instead of low end. dc_noswap: ; Move those characters. push es pop ds rep movsw mov cx,bp ; Figure out what color to make the new blanks. call get_blank_attrib mov al,' ' ; Blank out vacated region. rep stosw ; All done. cld ; restore normal REP state and pop di ; cursor address. dc_ret: ret ;---- set / reset mode --------------------------------------- ; Sets graphics/text mode; also sets/resets "no wrap at eol" mode. sm: mov cl, 0ffh ; set sm_rs: ; Is it "wrap at eol" ? cmp al,7 jnz sm_notwrap mov wrap_flag, cl ; true = wrap at EOL ret sm_notwrap: ; Is it "set highest number of screen lines available"? cmp al, 43 jnz sm_video ; Only valid for the Enhanced Graphics Adaptor on ; a monochrome display or an enhanced color display. ; Test presence of EGA by calling BIOS fn 12h.10h. mov ah, 12h mov bx, 0ff10h int 10h ; bh=0-1, bl=0-3 if EGA test bx, 0FEFCH jnz sm_done ; sorry, charlie ; 43 line mode only allowed in text modes, for now. cmp cs:video_mode, 4 jb DO_43L cmp cs:video_mode, 7 jnz sm_done DO_43L: xor ah,ah ; "Set video mode" mov al, video_mode ; Re-init current mode int 10h mov ax,1112h ; Load 8x8 font xor bl,bl ; (instead of 8x14) int 10h mov ax, 1200h ; Load new printscreen mov bl,20h int 10h mov ah,1 mov cx,0707h ; (Load cursor scan lines) int 10h ; | Patch; this gotten by painful observation of ; | IBM's professional editor. I think there's a ; | documented bug in Video Bios's "load cursor scan line" ; | call; try looking in latter 1985 PC Tech Journal. mov dx, port_6845 ; '6845' command reg mov al, 10 out dx, al inc dx mov al, 7 out dx, al ; set cursor start line ; Assume that gets us 43 lines. mov max_y, 42 jmp short sm_home sm_video: ; It must be a video mode. Call BIOS. xor ah,ah ; "set video mode" int 10h ; Assume that gets us 25 lines. mov max_y,24 sm_home: ; Read the BIOS buffer address/cursor position variables. mov ax,abs40 push ds 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 pop ds mov video_mode,al dec ah ; ah = max column mov max_x,ah ; Since cursor may end up in illegal position, it's best to ; just go home after switching video modes. mov cur_coords,0 call xy_to_regs sm_done: ret rm: xor cl,cl ; reset jmp sm_rs ansi_functions endp ; end dummy procedure block ;-------- Color table ----------------------------------------- ; Used in "set graphics rendition" colors equ 22 ; number of colors in table color_table: db 0, 000h,07h ; all attribs off; normal. db 1, 0ffh,08h ; bold db 4, 0f8h,01h ; underline db 5, 0ffh,80h ; blink db 7, 0f8h,70h ; reverse db 8, 088h,00h ; invisible db 30,0f8h,00h ; black foreground db 31,0f8h,04h ; red db 32,0f8h,02h ; green db 33,0f8h,06h ; yellow db 34,0f8h,01h ; blue db 35,0f8h,05h ; magenta db 36,0f8h,03h ; cyan db 37,0f8h,07h ; white db 40,08fh,00h ; black background db 41,08fh,40h ; red db 42,08fh,20h ; green db 43,08fh,60h ; yellow db 44,08fh,10h ; blue db 45,08fh,50h ; magenta db 46,08fh,30h ; cyan db 47,08fh,70h ; white code ends end