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Text File | 1994-01-06 | 28.3 KB | 957 lines

***************************** SYSTEM ************************************* ASMLIB system subroutines Copyright (C) 1991 - 1993 Douglas Herr all rights reserved ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ALLOCDOS: allocate memory block from DOS memory Source: allocdos.asm Call with: DX:AX = bytes requested Before using AllocDOS, you must release unused memory with ENDPROG (see STARTUP.ASM). Memory allocated with AllocDOS may be released with DOS function 49h Returns: if CF = 0, BX = segment address of allocated memory block if CF = 1, AH = AL = DOS error code Uses: AX, BX, flags Example: include asm.inc public myprog extrn allocdos:proc .data dseg dw ? ; storage for segment address of allocated memory bytes dd 100000 ; about 100k .code myprog proc ; program fragment assumes DS:@data . . . mov ax,word ptr bytes mov dx,word ptr bytes+2 ; DX:AX = bytes requested call allocdos jc alloc_error mov dseg,bx ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 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: $flags.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 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ COLOR16: calculate color value for palette register Source: color16.asm Call with: DS:[BX] pointing to red value (0-3), green value (0-3) and blue value (0-3) Assumes DS:@data; see also Palette16 Returns: AH = color value for 16-color palette register Uses: AH Supports: VGA 16-color modes (text or graphics) EGA 16-color modes, except with CGA monitor Example: .data c16 db 3 ; brightest red db 1 ; dim green db 0 ; no blue .code ; program fragment assumes DS:@data . . . lea bx,c16 call color16 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ DOSFREE: deteremines DOS memory available Source: dosfree.asm Call with: no parameters Returns: DX:AX = bytes available in conventional memory space For best results, release excess memory with ENDPROG (see STARTUP.ASM). Uses: DX, AX Example: call dosfree ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ENDPROG: determines program's size this is handy for dynamic memory allocation, or for TSR work Source: endprog.asm Call with: no parameters Returns: (small, medium, huge models) 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. ZSEG should be at the end of the program. (tiny model) AX = offset of end of the program's code and initialized data. See TINY.ASM startup code. If you add any object modules to ASMTINY.LIB, be certain any segments in the added modules are defined before LINK encounters ENDPROG, and that all segments are grouped in DGROUP. Be sure to review the .MAP file after linking. ZSEG should be at the end of the program. With TINY model, program stack extends beyond the end of the code and initialized data to the end of the 64k program segment. Uses: AX Example: see STARTUP.ASM or TINY.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 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ EXESIZE: determine size of .EXE program NOTE: not in ASMTINY.LIB or 286TINY.LIB Source: exesize.asm Call with: DS:[DX] pointing to ASCIIZ .EXE filename Returns: if CF = 1, AX = DOS error code if AX = 0, not an EXE-format file if CF = 0, DX:AX = bytes in .EXE file loaded by DOS program loader Note that additional data may be copied to the end of a DOS .EXE file with the DOS COPY /B command. This is handy for help screens or other such data that you want to keep with the .EXE file, but that you don't want to be loaded in memory with the program. If you do copy additional data to the .EXE file, EXESize will report only the portion of the file loaded in RAM by the DOS program loader, while FSize (in DISK.DOC) reports the entire file size. Uses: AX, DX, flags Example: ; ; code used to test EXEsize ; include asm.inc public testcode extrn exename:proc, exesize:proc extrn strndup:proc, i4tostr:proc extrn tprint:proc, getkey:proc .data extrn pspseg:word space db 20 dup(0) .code testcode proc mov es,pspseg call exename ; get name of this program call strndup ; copy to near heap ; startup code was assembled with /DHEAP mov dx,bx ; DS:[DX] -> EXE filename call exesize ; DX:AX = EXE program size lea si,space call i4tostr ; convert to ASCIIZ string xor dx,dx ; point to UL corner of screen mov ah,12 ; "can't miss it" color call tprint ; print it call getkey ; don't scroll off screen yet ret ; go back to calling code testcode endp end ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FARALLOC: allocate memory from a far heap Source: farheap.asm Call with: ES = segment address of far heap AX = requested block size Returns: if CF = 1, insufficient memroy available in heap if CF = 0, ES:[BX] = starting address of allocated memory Uses: BX, flags Example: see FarInit ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FARFREE: releases far heap memory previously allocated Source: farheap.asm Call with: ES:[BX] pointing to memory block to be released Returns: nothing Uses: AX, BX, flags Example: mov es,heap_seg mov bx,pointer call farfree ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FARINIT: initializes a far heap Source: farheap.asm Call with: ES = segment address of memory block to be managed by ASMLIB's far heap manager AX = size of memory block in bytes (2 < bytes < 32768) FarInit assumes that the memory block begins at ES:[0]. Any number of far heaps may be used if memory is available. Returns: if CF = 0, successful; if CF = 1, AX is out of range. Uses: flags Example: include asm.inc extrn allocdos:proc, farinit:proc .data heap_seg dw ? .code . . . mov ax,32767 xor dx,dx ; allocate 32k from DOS memory push ax call allocdos mov heap_seg,bx ; segment address of allocated block pop ax ; size of block jc not_enough_dos ; insufficient memory available mov es,heap_seg call farinit ; initialize this block . . mov ax,125 ; get 125 bytes from far heap mov es,heap_seg ; heap address call faralloc ; get far memory; returned at ES:[BX] jc not_enough_heap ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FARREALLOC: re-sizes a block of memory in a far heap Source: farheap.asm Call with: ES:[BX] = original pointer to memory block AX = new byte size Returns: if successful, CF = 0, ES:[BX] points to new block if not successful, CF = 1 Uses: BX, flags Example: mov es,heap_seg mov bx,pointer mov ax,newsize call farrealloc ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FINDMONO: detects a monochrome-compatible video card this is handy in 2-monitor systems. Source: findmono.asm (a$herc.asm, isega.asm, $6845.asm) Call with: no parameters Returns: if CF = 1, no monochrome monitor if CF = 0, AX = monitor code 0 = MDA 0101h = EGA monochrome 0301h = VGA monochrome 128 = Hercules or clone 144 = Hercules Graphics Card plus 208 = Hercules InColor Uses: AX, CF Supports: MDA, EGA & VGA MONO, HGC, HGC+, InColor Example: call findmono jc no_monochrome ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FLOPPIES: determine the number of floppy disk drives intalled Source: floppies.asm Call with: no parameters Returns: AX = number of floppy drives Uses: AX; all other registers and flags are saved Example: .model medium public myproc extrn floppies:proc .code myproc proc . call floppies ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ FLOPPYTYPE: determine the type of floppy disk drives intalled Source: floptype.asm Call with: DL = drive number (0 = drive A:) Returns: AX = floppy drive type 0 = invalid drive number 1 = 360k 2 = 1.2M 3 = 720k 4 = 1.44M Uses: AX, flags Example: .model medium public myproc extrn floppytype:proc .data drive_number db 0 .code myproc proc . mov dl,drive_number call floppytype or ax,ax jz bad_drive_number ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ GETCPU: detects cpu type Source: getcpu.asm Call with: no parameters Returns: AX = 0 if 8086/8088 AX = 1 if 80186/80188 AX = 2 if 80286 AX = 3 if 386 (SX or DX) AX = 4 if 486 (SX or DX) Uses: AX Example: call getcpu ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ GETCRT: determines active monitor type Source: getcrt.asm (a$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: 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 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISATT: determines if an ATT 6300-type display card is installed this equipment is like a CGA except that it has an additional 640 x 400 2-color graphics mode (mode 40h) Source: isatt.asm ($6845.asm, isevga.asm) Call with: no parameters Returns: if CF = 1, ATT 6300 display not present if CF = 0, ATT 6300 display is installed Uses: flags Example: include asm.inc public cgamode extrn isatt:proc .code cgamode proc mov ax,06h ; default: set CGA mode call isatt ; see if mode 40h is available jc set_mode ; nope mov ax,40h ; use ATT 6300 mode 40h set_mode: push bp ; required by old PC BIOS int 10h ; use BIOS to set mode pop bp ret cgamode endp end ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISEVGA: determines if an EGA or VGA is installed Source: isevga.asm Call with: no parameters Returns: if CF = 1, no EGA or VGA if CF = 0 DX = video memory in kbytes AL = monitor type AL = -1 if monitor is CGA AL = 0 if monitor is monochrome AL = 1 if monitor is EGA or better AH = EGA/VGA flag AH = 1 if EGA AH = 3 if VGA Uses: AX, DX, CF Example: call isevga jc no_evga ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISHERC: determines if a Hercules card or compatible is installed and if so, determines if it is the active video system. Source: isherc.asm (a$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 ($flags.asm) Parameters: none Returns: AX = number of mouse buttons AX = 0 if no mouse or mouse driver installed Uses: AX Example: include asm.inc .code . . . call ismouse or ax,ax jz no_mouse ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISSEVGA: determines if a Super EGA or Super VGA is installed Source: issevga.asm ($sega.asm, $svga.asm) Parameters: none Returns: if CF = 1, no Super EGA or Super VGA recognized by ASMLIB if CF = 0 AH = 1: Super EGA AH = 3: Super VGA AL = 1 if Paradise AL = 2 if Everex AL = 3: Tseng VGA chipset AL = 4: Oak Technologies AL = 5: Western Digital (Paradise) OEM AL = 6: ATI AL = 7: Compaq AL = 8: NCR AL = 9: Trident AL =10: Video7 AL =11: Genoa AL =12: Cirrus AL =13: Chips & Technologies AL =14: Tseng 4000 AL =15: Ahead A AL =16: Ahead B AL =17: Trident 8900 See also IsEVGA Uses: AX, CF Example: call issevga jc no_superevga ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ISVM86: determines if 32-bit processor is in V86 mode Source: isvm86.asm (getcpu.asm) Parameters: none V86 is used by Expanded Memory device drivers such as QEMM and EMM386 to provide Expanded Memory using extended memory of 32-bit systems such as 386 (DX and SX) and 486 (DX and SX) computers Returns: AX = processor type (see GetCPU) if CF = 0, 32-bit processor in V86 mode if CF = 1, no 32-bit processor or not V86 mode Uses: AX, flags Example: include asm.inc public test_for_vm86 extrn isvm86:proc .data vm86 db 'VM86 detected',0Dh,0AH,'$' notvm86 db 'VM86 not detected',0Dh,0AH,'$' .code test_for_vm86 proc lea dx,vm86 call isvm86 jnc exit lea dx,notvm86 exit: mov ah,9 ; DOS function: display string int 21h ret test_for_vm86 endp ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 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: $flags.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 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MOUSETYPE: determine mouse type (bus, serial, PS/2, etc.) Source: mousetyp.asm Call with: no parameters assumes mouse driver has been loaded (see IsMouse) Returns: AX = mouse type 0 = mouse driver error 1 = bus mouse 2 = serial mouse 3 = InPort mouse 4 = PS/2 mouse 5 = HP mouse Uses: AX, flags Example: include asm.inc extrn mousetype:proc extrn ismouse:proc .code . . . call ismouse or ax,ax ; is a mouse installed? jz no_mouse call mousetype ; what kind of mouse? or ax,ax jz mouse_error . . ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ MSAVE: save mouse state Source: msave.asm (dosalloc.asm) MRESTORE: restore previously saved mouse state Source: msave.asm (dosalloc.asm) MSave and MRestore are handy when you have installed a mouse event handler and you will be using the SYSTEM command, where some other program may reset or otherwise change the mouse event trapping. MSave allocates a buffer, saves the mouse state in the buffer, resets the mouse driver and returns the buffer address. MRestore restores a specified mouse state and releases the buffer. Both MSave and MRestore assume that you already know there is a mouse in the system. Call with: MSAve: no paramerters MRestore: AX = buffer address returned by prior MSave call Returns: if CF = 1, AH = MS-DOS error code if CF = 0, no error; MSave returns buffer address in AX Uses: AX, flags Example: include asm.inc extrn msave:proc, mrestore:proc .data save_mouse dw 0 .code ; program fragment assumes DS:@data . . . ; save the mouse driver state ; I've already checked to see if there's a mouse call msave jc dos_error mov save_mouse,ax . . ; some other subroutine has messed with the mouse mov ax,save_mouse ; buffer address from previous MSave call mrestore jc dos_error ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ PALETTE16: change palette in EGA, VGA or SVGA 16-color mode changing the palette changes the actual color associated with a color attribute Source: palet16.asm Call with: BH = color value (see Color16 in SYSTEM.DOC) BL = color attribute to map color to (0-0Fh) restore default palette with BH = BL = 0FFh Returns: nothing Uses: nothing Example: .data c16 db 3 ; brightest red db 1 ; dim green db 0 ; no blue .code ; program fragment assumes DS:@data . . . lea bx,c16 call color16 mov bh,ah ; color value in BH mov bl,15 ; color attribute 0Fh call palette16 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ 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: ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ WHICHVGA: determine if VGAKIT-compatible SuperVGA is installed See SVGA16 and SVGA256 in MODE.DOC. Source: banks.asm Call with: no parameters Returns: if VGAKIT-compatible Super VGA is installed, AX <> 0. if no VGAKIT equipment is installed, AX = 0. Uses: AX Example: see SVGA16 in MODE.DOC