Power-Programmierung

home *** CD-ROM | disk | FTP | other *** search

/ Power-Programmierung / CD1.mdf / assemblr / library / screen / asmlib / system.doc < prev next >

Wrap

Text File | 1992-06-13 | 15.8 KB | 538 lines

***************************** SYSTEM ************************************* ASMLIB system subroutines Copyright (C) 1991, 1992 Douglas Herr all rights reserved ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ BREAKTRAP: initialize Ctrl+Break trap BREAKRELEASE:restore previous Ctrl+Break handler Source: break.asm BREAKFLAG: public byte in DGROUP, indicating Ctrl+Break key press Source: asmflags.asm Call with: no parameters BreakTrap uses well-behaved methods to trap Ctrl+Break, Ctrl+C and Ctrl-Alt-Del key sequences. When one of these key combinations is pressed, ASMLIB's break trap sets the public flag "breakflag" in the data area. BreakRelease de-activates ASMLIB's break trap, restoring the previous Ctrl+Break handler. BreakFlag = 0 until a monitored key combination is pressed, at which time breakflag is set equal to 1. If you use BreakTrap, you MUST call BreakRelease before the end of your program, or you will find yourself reaching for the Big Red Switch. See STARTUP.ASM. Returns: nothing Uses: nothing Example: see STARTUP.ASM ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ DOSALLOC: allocate memory block from unused DOS memory Source: dosalloc.asm Call with: DX:AX = number of bytes to allocate DOSAlloc uses DOS function 48h to allocate memory from free DOS memory. See STARTUP.ASM and subroutine ENDPROG. Returns: if CF = 0, AX = segment address of start of memory block offset of start of memory block = 0 if CF = 1, insufficient DOS memory space is available. Uses: AX, CF; all other flags and registers are saved Example: .model huge extrn bitblockbytes:proc, dosalloc:proc .code ; this example uses bitblockbytes to calculate the memory required ; to save a bit block on a graphics screen . . . lea bx,corners ; point to bit block corner coordinates call bitblockbytes ; returns DX:AX = number of bytes required call dosalloc jc no_memory ; do some error handling stuff ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ENDPROG: determines program's code, static data and stack size this is handy for dynamic memory allocation, or for TSR work Source: endprog.asm Call with: no parameters Returns: AX = segment address of end of program. See STARTUP.ASM. ENDPROG defines ZSEG as the last segment in the program. If you add any object modules to ASMLIB.LIB, be certain any segments in the added modules are defined before LINK encounters ENDPROG. Be sure to review the .MAP file after linking. Uses: AX Example: see STARTUP.ASM ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ EXENAME: determine the full path and filename of the executing program Source: exename.asm (strlen.asm) Call with: ES = PSP segment (see STARTUP.ASM) Returns: ES:[BX] pointing to the the name of the executing program, including drive and full path, CX = length of the filename. The filename returned is an ASCIIZ string, and may be mixed upper- and lower-case characters. Uses: ES, BX, CX; all other registers and flags are saved. Example: include asm.inc extrn exename:proc .data extrn pspseg:word .code ; program fragment assumes DS:@data . . . mov es,pspseg call exename ; string returned at ES:[BX] can be ; copied to heap with STRNDUP ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FINDMONO: detects a monochrome-compatible video card this is handy in 2-monitor systems. Source: findmono.asm (a$herc.asm, isega.asm, find6845.asm) Parameters: none Returns: if CF = 1, no monochrome monitor if CF = 0, AX = monitor code 0 = MDA 0101h = EGA monochrome 0301h = VGA monochrome 128 = Hercules or clone 144 = Hercules Graphics Card plus 208 = Hercules InColor Uses: AX, CF Supports: MDA, EGA & VGA MONO, HGC, HGC+, InColor Example: call findmono jc no_monochrome ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FLOPPIES: determine the number of floppy disk drives intalled Source: floppies.asm Call with: no parameters Returns: AX = number of floppy drives Uses: AX; all other registers and flags are saved Example: .model medium public myproc extrn floppies:proc .code myproc proc . call floppies ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FLOPPYTYPE: determine the number of floppy disk drives intalled Source: floptype.asm Call with: DL = drive number (0 = drive A:) Returns: AX = floppy drive type 0 = invalid drive number 1 = 360k 2 = 1.2M 3 = 720k 4 = 1.44M Uses: AX, flags Example: .model medium public myproc extrn floppytype:proc .data drive_number db 0 .code myproc proc . mov dl,drive_number call floppytype or ax,ax jz bad_drive_number ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ GETCPU: detects cpu type Source: getcpu.asm Call with: no parameters Returns: AX = 0 if 8086/8088 AX = 1 if 80186/80188 AX = 2 if 80286 AX = 3 if 386 (SX or DX) AX = 4 if 486 (SX or DX) Uses: AX Example: call getcpu ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ GETCRT: determines active monitor type Source: getcrt.asm (a$herc.asm, isevga.asm) Call with: no parameters Returns: AX = code for active video system CGA = -1 MDA = 0 EGA mono = 0100h VGA mono = 0300h EGA color = 1 MCGA = 2 VGA color = 3 HGC = 128 HGC+ = 144 InColor = 208 Note: GetCRT may be re-assembled with the /DNOHERC switch to eliminate code which detects Hercules equipment Uses: AX Supports: CGA, MCGA, MDA, HGC, HGC+, InColor, EGA, VGA Example: call getcrt ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ HALLOC: allocates memory from near heap Source: heap.asm Call with: AX = bytes requested; assumes DS:@data heap must be initialized with hinit Returns: if space available: BX = near pointer for allocated data if space not available: CF = 1 Uses: AX, BX, flags Example: mov ax,bytes call halloc jc no_memory ; check to see if there was enough space ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ HFREE: releases heap memory previously allocated Source: heap.asm Call with: BX = near pointer to memory block; assumes DS:@data Returns: nothing Uses: AX, BX, flags Example: mov bx,pointer call hfree ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ HINIT: initializes heap manager Source: heap.asm Call with: AX = number of bytes to be managed by heap manager 2 <=bytes<= 32767 BX = near pointer to memory block to be managed assumes DS:@data Returns: CF = 0 if ok, CF = 1 if bad parameter (bytes too small or too large) Uses: flags Example: .data heap db 32767 dup(0) .code mov ax,@data mov ds,ax assume ds:@data mov ax,32767 lea bx,heap call hinit ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ HMAX: determines largest free block in asmlib's near heap Source: heap.asm Call with: no parameters Returns: AX = block size in bytes AX = -1 if the heap has not been initialized Uses: AX Example: call hmax ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ HREALLOC: re-sizes a block of memory in the near heap Source: heap.asm Call with: BX = original pointer to memory block AX = new byte size Returns: if successful, CF = 0, BX = new block pointer if not successful, CF = 1 Uses: BX, flags Example: mov bx,pointer mov ax,newsize call hrealloc ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISANSI: determines if ANSI or compatible is loaded and active Source: isansi.asm Parameters: none Returns: CF = 1 if no ANSI device driver loaded and active CF = 0 if ANSI loaded and active Uses: CF Example: call isansi ; let's see if ansi.sys is loaded jc no_ansi ; jump if not ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISEVGA: determines if an EGA or VGA is installed Source: isevga.asm Call with: no parameters Returns: if CF = 1, no EGA or VGA if CF = 0 DX = video memory in kbytes AL = monitor type AL = -1 if monitor is CGA AL = 0 if monitor is monochrome AL = 1 if monitor is EGA or better AH = EGA/VGA flag AH = 1 if EGA AH = 3 if VGA Uses: AX, DX, CF Example: call isevga jc no_evga ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISHERC: determines if a Hercules card or compatible is installed and if so, determines if it is the active video system. Source: isherc.asm (a$herc.asm) Call with: no parameters Returns: if CF = 1, no Hercules or compatible installed if CF = 0, AX = Hercules model 128 = Hercules Graphics Card or compatible; active 144 = Hercules Graphics Card Plus; active 208 = Hercules InColor card; active -128 = Hercules Graphics Card or compatible; not active -144 = Hercules Graphics Card Plus; not active -208 = Hercules InColor card; not active Uses: AX, CF; all other flags and registers are saved Example: call isherc jc no_herc ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISMOUSE: determines if a mouse is installed Source: ismouse.asm (asmflags.asm) Parameters: none Returns: AX = number of mouse buttons AX = 0 if no mouse or mouse driver installed Uses: AX Example: include asm.inc .code . . . call ismouse or ax,ax jz no_mouse ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISSEVGA: determines if a Super EGA or Super VGA is installed Source: issevga.asm Parameters: none Returns: if CF = 1, no Super EGA or Super VGA recognized by ASMLIB if CF = 0 if AH = 1: (Super EGA) AL = 1 if Paradise EGA 480 AL = 2 if Everex EGA if AH = 3: (Super VGA) AL = 1 if Paradise VGA AL = 3 if Tseng VGA chipset AL = 4 if Oak VGA AL = 5 if Western Digital VGA chipset See also IsEVGA Uses: AX, CF Example: call issevga jc no_superevga ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MATHCHIP: determines if 80x87 math coprocessor is installed Source: mathchip.asm Parameters: none Returns: AX = code for 80x87 model 0 = not installed 1 = 8087 2 = 287 3 = 387 (DX or SX) 4 = 487 (486DX or 487SX) If the coprocessor is present, it is initilaized by MathChip. Uses: AX, all 80x87 registers Example: call mathchip ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MOUSEINIT: initializes mouse driver if mouse present Source: mouseini.asm MOUSEFLAG: public byte in DGROUP indicating mouse buttons Source: asmflags.asm Parameters: assumes DS:@data Returns: if mouse installed, ZF = 0 and AX = number of mouse buttons also updates mouseflag if no mouse, ZF = 1 and AX = 0 Uses: AX, flags Example: include asm.inc extrn mouseinit:proc .code ; program fragment assumes DS:@data . . . call mouseinit jz no_mouse ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ SYSTEM: execute a second copy of COMMAND.COM; optionally runs another program. Source: system.asm (strlen.asm) Parameters: ES = PSP segment DS:[BX] points to command tail if DS:[BX] points to a nul byte, control is transfered to the second copy of COMMAND.COM and you get a DOS prompt. control is passed back to the calling program when EXIT is entered at the DOS prompt. if DS:[BX] points to an ASCIIZ string with the name of a program (and optional command line parameters), the program will be executed, and control will pass back to the calling program at the termination of the second program. Returns: nothing Uses: AX Example: include asm.inc ; I want to go to DOS temporarily to format a 720k disk extrn system:proc .data ; PSP segment is saved here by my startup code pspseg dw ? cmdtail db 'format a: /n:9 /t:80',0 .code ; program fragment assumes DS:@data . . lea bx,cmdtail ; DS:[BX] points to command tail mov es,pspseg call system ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ USE32K: limit Hercules equipment to 32k memory (128k on InColor) USE64K: allow full 64k on HGC and HGC+ (256k on InColor) Source: a$herc.asm Requires Hercules or compatible Call with: no parameters Use32k is equivalent to the Hercules "half" configuration Use64k is equivalent to the Hercules "full" configuration ASMLIB's default is "half". Use this configuration if you have a 2-monitor system, unless you are using the Hercules CGA card. Returns: nothing Uses: nothing Example: ; in this example I'm determining if a Hercules is installed ; and setting the configuration to "full" extrn IsHerc:proc extrn Use64k:proc .code . . . call IsHerc jc no_herc or ax,ax js use_only_half ; use_only_half if HGC is not default monitor call use64k ; else use all Hercules memory use_only_half: