diff options
Diffstat (limited to 'pc.c')
| -rw-r--r-- | pc.c | 270 |
1 files changed, 270 insertions, 0 deletions
@@ -0,0 +1,270 @@ +/* pc.c */ + +/* Author: + * Guntram Blohm + * Buchenstrasse 19 + * 7904 Erbach, West Germany + * Tel. ++49-7305-6997 + * sorry - no regular network connection + */ + +/* This file implements the ibm pc bios interface. See IBM documentation + * for details. + * If TERM is set upon invocation of elvis, this code is ignored completely, + * and the standard termcap functions are used, thus, even not-so-close + * compatibles can run elvis. For close compatibles however, bios output + * is much faster (and permits reverse scrolling, adding and deleting lines, + * and much more ansi.sys isn't capable of). GB. + */ + +#include "config.h" +#include "vi.h" + +#if MSDOS + +#include <dos.h> + +static void video(); + +/* vmode contains the screen attribute index and is set by attrset.*/ + +int vmode; + +/* The following array contains attribute definitions for + * color/monochrome attributes. Screen selects one of the sets. + * Maybe i'll put them into elvis options one day. + */ + +static int screen; +static char attr[2][5] = +{ + /* :se: :so: :VB: :ul: :as: */ + { 0x1f, 0x1d, 0x1e, 0x1a, 0x1c, }, /* color */ + { 0x07, 0x70, 0x0f, 0x01, 0x0f, }, /* monochrome */ +}; + +/* + * bios interface functions for elvis - pc version + */ + +/* cursor up: determine current position, decrement row, set position */ + +void v_up() +{ + int dx; + video(0x300,(int *)0,&dx); + dx-=0x100; + video(0x200,(int *)0,&dx); +} + +#ifndef NO_CURSORSHAPE +/* cursor big: set begin scan to end scan - 4 */ +void v_cb() +{ + int cx; + video(0x300, &cx, (int *)0); + cx=((cx&0xff)|(((cx&0xff)-4)<<8)); + video(0x100, &cx, (int *)0); +} + +/* cursor small: set begin scan to end scan - 1 */ +void v_cs() +{ + int cx; + video(0x300, &cx, (int *)0); + cx=((cx&0xff)|(((cx&0xff)-1)<<8)); + video(0x100, &cx, (int *)0); +} +#endif + +/* clear to end: get cursor position and emit the aproppriate number + * of spaces, without moving cursor. + */ + +void v_ce() +{ + int cx, dx; + video(0x300,(int *)0,&dx); + cx=COLS-(dx&0xff); + video(0x920,&cx,(int *)0); +} + +/* clear screen: clear all and set cursor home */ + +void v_cl() +{ + int cx=0, dx=((LINES-1)<<8)+COLS-1; + video(0x0600,&cx,&dx); + dx=0; + video(0x0200,&cx,&dx); +} + +/* clear to bottom: get position, clear to eol, clear next line to end */ + +void v_cd() +{ + int cx, dx, dxtmp; + video(0x0300,(int *)0,&dx); + dxtmp=(dx&0xff00)|(COLS-1); + cx=dx; + video(0x0600,&cx,&dxtmp); + cx=(dx&0xff00)+0x100; + dx=((LINES-1)<<8)+COLS-1; + video(0x600,&cx,&dx); +} + +/* add line: scroll rest of screen down */ + +void v_al() +{ + int cx,dx; + video(0x0300,(int *)0,&dx); + cx=(dx&0xff00); + dx=((LINES-1)<<8)+COLS-1; + video(0x701,&cx,&dx); +} + +/* delete line: scroll rest up */ + +void v_dl() +{ + int cx,dx; + video(0x0300,(int *)0,&dx); + cx=(dx&0xff00)/*+0x100*/; + dx=((LINES-1)<<8)+COLS-1; + video(0x601,&cx,&dx); +} + +/* scroll reverse: scroll whole screen */ + +void v_sr() +{ + int cx=0, dx=((LINES-1)<<8)+COLS-1; + video(0x0701,&cx,&dx); +} + +/* set cursor */ + +void v_move(x,y) + int x, y; +{ + int dx=(y<<8)+x; + video(0x200,(int *)0,&dx); +} + +/* put character: set attribute first, then execute char. + * Also remember if current line has changed. + */ + +int v_put(ch) + int ch; +{ + int cx=1; + ch&=0xff; + if (ch>=' ') + video(0x900|ch,&cx,(int *)0); + video(0xe00|ch,(int *)0, (int *)0); + if (ch=='\n') + { exwrote = TRUE; + video(0xe0d, (int *)0, (int *)0); + } + return ch; +} + +/* determine number of screen columns. Also set attrset according + * to monochrome/color screen. + */ + +int v_cols() +{ + union REGS regs; + regs.h.ah=0x0f; + int86(0x10, ®s, ®s); + if (regs.h.al==7) /* monochrome mode ? */ + screen=1; + else + screen=0; + return regs.h.ah; +} + +/* Getting the number of rows is hard. Most screens support 25 only, + * EGA/VGA also support 43/50 lines, and some OEM's even more. + * Unfortunately, there is no standard bios variable for the number + * of lines, and the bios screen memory size is always rounded up + * to 0x1000. So, we'll really have to cheat. + * When using the screen memory size, keep in mind that each character + * byte has an associated attribute byte. + * + * uses: word at 40:4c contains memory size + * byte at 40:84 # of rows-1 (sometimes) + * byte at 40:4a # of columns + */ + +int v_rows() +{ + int line, oldline; + + /* screen size less then 4K? then we have 25 lines only */ + + if (*(int far *)(0x0040004cl)<=4096) + return 25; + + /* VEGA vga uses the bios byte at 0x40:0x84 for # of rows. + * Use that byte, if it makes sense together with memory size. + */ + + if ((((*(unsigned char far *)(0x0040004aL)*2* + (*(unsigned char far *)(0x00400084L)+1))+0xfff)&(~0xfff))== + *(unsigned int far *)(0x0040004cL)) + return *(unsigned char far *)(0x00400084L)+1; + + /* uh oh. Emit '\n's until screen starts scrolling. */ + + v_move(oldline=0, 0); + for (;;) + { + video(0xe0a,(int *)0,(int *)0); + video(0x300,(int *)0,&line); + line>>=8; + if (oldline==line) + return line+1; + oldline=line; + } +} + +/* the REAL bios interface -- used internally only. */ + +static void video(ax, cx, dx) + int ax, *cx, *dx; +{ + union REGS regs; + + regs.x.ax=ax; + if ((ax&0xff00)==0x600 || (ax&0xff00)==0x700) + regs.h.bh=attr[screen][vmode]; + else + { + regs.h.bh=0; + regs.h.bl=attr[screen][vmode]; + } + if (cx) regs.x.cx=*cx; + if (dx) regs.x.dx=*dx; + int86(0x10, ®s, ®s); + if (dx) *dx=regs.x.dx; + if (cx) *cx=regs.x.cx; +} + +/* The following function determines which character is used for + * commandline-options by command.com. This system call is undocumented + * and valid for versions < 4.00 only. + */ + +int switchar() +{ + union REGS regs; + regs.x.ax=0x3700; + int86(0x21, ®s, ®s); + return regs.h.dl; +} + +#endif |