******************** EXPANDED AND EXTENDED MEMORY ************************** ASMLIB's EMS subroutines detect and manipulate Expanded Memory hardware and software. Expanded memory, when installed in any PC, can help solve many memory limitation problems. Call IsEMS before using any other ASMLIB EMS subroutines. EMS memory is allocated in blocks of 16k increments Error codes returned by EMS functions are: AH = 0 no error AH = 80h error in memory manager software AH = 81h error in expanded memory hardware AH = 84h bad function code passed to memory manager AH = 85h no EMM handles available AH = 89h you tried to allocate zero pages ASMLIB also supports XMS-compatible extended memory. You must call IsXMS to determine if XMS memory is available before using any ASMLIB XMS subroutines. XMS memory is available on many 286 or better computers with a suitable driver. On 286 computers, XMS memory will be much slower than EMS memory. XMS memory is not available on XT (or compatible) computers. XMS memory is allocated in 1k increments XMS error codes include: AH = 0 no error AH = 0A0h all extended memory is allocated AH = 0A1h no handles available AH = 0A2h, 0A3h, 0A5h handle is invalid AH = 0A4h, 0A6h offset is invalid AH = 0A7h length is invalid ASMLIB's EMS and XMS subroutines were written with identical calling parameters and identical returned information for comparble EMS and XMS subroutines. For example, AllocEMS and AllocXMS are both called with DX:AX = the number of bytes requested. 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ALLOCEMS: allocates EMS memory Source: ems.asm Call with: DX:AX = number of bytes of memory to allocate EMS memory is allocated in 16k blocks. AllocEMS will allocate multiple blocks if nessesary. NOTE: You must first use IsEMS to determine if Expanded memory is installed. Returns: if CF = 0, BX = EMS handle if CF = 1, AH = EMS error code Uses: AX, BX, flags Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ALLOCXMS: allocates XMS memory Source: xms.asm Call with: DX:AX = number of bytes of memory to allocate XMS memory is allocated in 1k blocks. AllocXMS will allocate multiple blocks if nessesary. NOTE: You must first use IsXMS to determine if XMS Extended memory is available. Returns: if CF = 0, BX = XMS handle if CF = 1, AH = XMS error code Uses: AX, BX, flags Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� EMGET: copy data from EMS memory to system RAM Source: emputget.asm ($emspage.asm) Call with: BX = EMS handle ES:[DI] pointing to destination buffer DS:[SI] pointing to 4-byte offset in EMS block DX:AX = number of bytes to copy Returns: if CF = 0, no error if CF = 1, AH = EMS error code Uses: AX, flags Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� EMMVER: determines Expanded Memory Manager version Source: emmver.asm Call with: no parameters Returns: if CF = 1, AH = EMS error code if CF = 0, AH = major version number AL = minor version number Uses: AX, flags Example: include asm.inc extrn isems:proc, emmver:proc .code . . . call isems jc no_ems call emmver ; get emm version jc ems_error cmp ah,4 ; version 4.x? jb version3x ; nope, an older EMM version 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� EMPUT: copy data to EMS memory from system RAM Source: emputget.asm ($emspage.asm) Call with: BX = EMS handle ES:[DI] pointing to data to copy DS:[SI] pointing to 4-byte offset in EMS block DX:AX = number of bytes to copy Returns: if CF = 0, no error if CF = 1, AH = EMS error code Uses: AX, flags Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� EMSFREE: determine free EMS memory Source: emsfree.asm Call with: no parameters EMSFree does not verify that EMS memory is installed; you should call IsEMS to determine if EMS memory is installed before using this subroutine. Do not confuse this subroutine with FreeEMS, which releases a previously allocated EMS block and handle. Returns: DX:AX = bytes of EMS memory available Uses: AX, DX, flags Example: include asm.inc public myprog extrn isems:proc, emsfree:proc .code myprog proc call isems ; see if EMS memory is installed jc nope call emsfree ; is enough available? . . . 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� EMSTOTAL: determine total EMS memory installed Source: emsfree.asm Call with: no parameters EMSTotal does not verify that EMS memory is installed; you should call IsEMS to determine if EMS memory is installed before using this subroutine. Returns: DX:AX = bytes of EMS memory installed Uses: AX, DX, flags Example: include asm.inc public myprog extrn isems:proc, emstotal:proc .code myprog proc call isems ; see if EMS memory is installed jc nope call emstotal ; how much? . . . 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� FREEEMS: releases an EMS memory block and handle Source: ems.asm Call with: BX = EMS handle NOTE: DOS does not release EMS memory when your program returns to DOS. Your program must close any open EMS handles before quitting, or the EMS memory associated with the handles will be unavailable to other programs. Do not confuse this subroutine with EMSFree, whick determines the EMS memory available. Returns: if CF = 0, no error if CF = 1, AH = EMS error code Uses: AX, flags Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� FREEXMS: releases an XMS memory block and handle Source: xms.asm Call with: BX = XMS handle NOTE: DOS does not release XMS memory when your program returns to DOS. Your program must close any open XMS handles before quitting, or the XMS memory associated with the handles will be unavailable to other programs. Do not confuse this subroutine with XMSFree, whick determines the XMS memory available. Returns: if CF = 0, no error if CF = 1, AH = XMS error code Uses: AX, flags Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ISEMS: detects EMS driver Source: isems.asm Call with: no parameters Returns: if CF = 1, no Expanded Memory manager installed if CF = 0, EMS memory is installed Uses: CF Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� ISXMS: detects XMS driver Source: isxms.asm Call with: no parameters Returns: if CF = 1, no XMS driver is installed if CF = 0, XMS memory is available Uses: CF Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� XMGET: copy data from XMS memory to system RAM Source: xmputget.asm (xms.asm) Call with: BX = XMS handle ES:[DI] pointing to destination buffer DS:[SI] pointing to 4-byte offset in XMS block DX:AX = number of bytes to copy Returns: if CF = 0, no error if CF = 1, AH = XMS error code Uses: AX, flags Example: see example code at the end of this file 같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같같� XMPUT: copy data to XMS memory from system RAM Source: xmputget.asm (xms.asm) Call with: BX = XMS handle ES:[DI] pointing to data to copy DS:[SI] pointing to 4-byte offset in XMS block DX:AX = number of bytes to copy Returns: if CF = 0, no error if CF = 1, AH = XMS error code Uses: AX, flags Example: see example code at the end of this file ; EXPANDED AND EXTENDED MEMORY EXAMPLE CODE ; This example determines if EMS or XMS memory is installed, allocates ; 32k of EMS or XMS memory, copies a Herules graph to the allocated memory ; and later, copies the data back to the video buffer and releases ; the memory block include asm.inc public herc2x extrn isems:proc, isxms:proc extrn allocems:proc, allocxms:proc extrn emput:proc, xmput:proc extrn emget:proc, xmget:proc extrn freeems:proc, freexms:proc .data IF @codesize xalloc dd 0 xput dd 0 xget dd 0 xfree dd 0 ELSE xalloc dw 0 xput dw 0 xget dw 0 xfree dw 0 ENDIF xoffset dw 0,0 xhandle dw 0 xerror dw 0 .code herc2x proc ; program fragment assumes DS:@data ; set up default conditions: use EMS mov xerror,offset ems_error mov word ptr xalloc,offset allocems mov word ptr xput,offset emput mov word ptr xget,offset emget mov word ptr xfree,offset freeems IF @codesize mov ax,seg allocems mov word ptr xalloc+2,ax ; all ASMLIB code in same segment mov word ptr xput+2,ax mov word ptr xget+2,ax mov word ptr xfree+2,ax ENDIF ; see if EMS is installed call isems jnc allocate_memory ; EMS not installed - see if XMS memory is avaialble ; set up for XMS subroutines mov xerror,offset xms_error mov word ptr xalloc,offset allocxms mov word ptr xput,offset xmput mov word ptr xget,offset xmget mov word ptr xfree,offset freexms IF @codesize mov ax,seg allocxms mov word ptr xalloc+2,ax ; all ASMLIB code in same segment mov word ptr xput+2,ax mov word ptr xget+2,ax mov word ptr xfree+2,ax ENDIF call isxms jc foiled_again ; don't use EMS or XMS ; allocate 32k allocate_memory: mov ax,32768 xor dx,dx ; DX:AX = 32768 call xalloc ; allocate EMS or XMS memory block jc xerror mov xhandle,bx ; save the handle ; copy the graph to EMS mov di,0B000h ; Hercules buffer mov es,di xor di,di ; ES:[BX] -> video buffer mov ax,32768 ; copy entire graph lea si,xoffset ; start at offset 0 in memory block call xput ; copy the graph to memory jc xerror ; later ... ; copy the graph back to the video buffer mov bx,xhandle mov dx,0B000h mov es,dx xor di,di ; ES:[DI] points to destination mov ax,32768 ; copy all 32k xor dx,dx ; DX:AX = 32768 lea si,xoffset ; start at offset 0 in memory block call xget ; copy the graph back to video buffer jc xerror ; all done with graph copy; release the memory block call xfree jc xerror