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Assembly Source File | 1993-06-19 | 35.9 KB | 1,111 lines

comment * Author: Yousuf J. Khan Purpose: To detect what type of video adapter is installed. Note: Work was based on source code inside Richard Wilton's "Programmer's Guide to PC & PS/2 Video Systems" book. However it's been heavily reworked to a more (dare I say?) understandable format. Also Super VGA tests were put in, something completely missing from Wilton's book. * .model tiny ;.stack 200h .data std0type db 0 ;first video subsystem type ext0type db 0 ;extended info on first subsystem std1type db 0 ;second video subsystem type ext1type db 0 ;extended info on second subsystem vidflag record monofound:1,colorfound:1 egatype vidflag <0,0> ;Was a mono or color EGA found? ; ;video adapter codes (based on codes returned by VGA BIOS DC codes): ;-these codes are used when a VGA BIOS is not found and other tests ; need to be performed to determine video type ;-it was decided to use the VGA BIOS DC codes for simplicity ;-see findVGA procedure for list of VGA DCCs. ; NoDISP equ 0 ;no display MONO equ 1 CGA equ 2 cEGA equ 4 ;color EGA mEGA equ 5 ;mono EGA .code org 100h ;*.COM start offset start: call findVGA ;look for a VGA or MCGA comment \ After executing VGA BIOS routines, the VGA BIOS itself will have done all the work of determining what is installed so no need to do any further tests. The "findVGA" subprocedure will set the CF upon returning, if a VGA BIOS was found. \ jc endtests ;found VGA/MCGA, end of tests call findEGA ;look for an EGA call findCGA ;look for a CGA call findMono ;look for an MDA or HGC endtests: call write_msg ;write found info to screen, set ; errorlevel mov ah, 4ch ;end program int 21h findVGA proc comment * Purpose: determine if a MCGA/VGA/SVGA display is installed Entry: nothing Return: CF set if found, clear if not * mov ax, 1A00h ;get Displ Combo Code info int 10h cmp al, 1Ah ;VGA-only BIOS function jne noVGA ; not supported => no VGA comment \ Upon Return from Int 10h, AX=1A00h: BL=primary adapter DCC BH=secondary adapter DCC Values for display combination code: 00h no display 01h monochrome adapter w/ monochrome display 02h CGA w/ color display 03h reserved 04h EGA w/ color display 05h EGA w/ monochrome display 06h PGA w/ color display 07h VGA w/ monochrome analog display 08h VGA w/ color analog display 09h reserved 0Ah MCGA w/ digital color display 0Bh MCGA w/ monochrome analog display 0Ch MCGA w/ color analog display FFh unknown display type \ push bx ;interpretDCC destroys contents of BH call interpretDCC ;this proc looks for extended info mov [std0type], bl ;save normal info mov [ext0type], bh ;save extended info pop bx push bx ;Since proc interpretDCC only works on info in BL, we must ; exchange BL with BH. xchg bh, bl call interpretDCC mov [std1type], bl ;save normal info mov [ext1type], bh ;save extended info pop bx stc ;found VGA/MCGA, so set CF before ret jmp endVGAtest noVGA: clc endVGAtest: ret interpretDCC proc comment * Purpose: Interprets information returned by the DCC Upon Entry: BL=normal DCC of desired video subsystem BH=will be destroyed, replaced with ext code Upon Return: BL=normal DCC returned (MDA,CGA,EGA,PGA,MCGA,VGA,etc) BH=extended code (HGC,SVGA), 0 if none * mov bh, 0 ;Assume no extended attribs cmp bl, 0 ;If 0, then no display card je end_interpret cmp bl, 1 ;Mono je monotests jmp CGAtests monotests: ; ;If we find a monochrome adapter, then we need to do special ; further tests to see if we have just an MDA or one of the ; Hercules cards. ; mov bh, bl ;save normal DCC in BH call findHGC ;MDA or HGC? value returned in ; BL xchg bh, bl ;BL=normal,BH=extended jmp end_interpret CGAtests: cmp bl, 2 ;CGA je end_interpret cmp bl, 6 ;EGA or PGA jbe end_interpret cmp bl, 8 ;BL=7,8: VGA ja end_interpret ; ;If we find a VGA, then we need to do extra tests to see whose ; VGA chipset it is. ; mov bh, bl ;save BL in BH call findSVGA ;search for SVGA adapter xchg bh, bl ;BH=extended, BL=normal end_interpret: ret endp endp findSVGA proc comment * Purpose: To search for specific SVGA types, including VESA compatibility. Entry: Nothing Return: BL=SVGA type * comment \ List of SVGA types: Brand Type ----- ---- ATI 1─┐ Ahead 2 │ These chipsets all have Paradise 3 │ easily identifiable BIOS based Oak 4 │ identification methods. Genoa 5─┘ Cirrus 6─┐ Chips&Tech 7 │ These chipsets require complicated Tseng 8 │ register twiddlings to identify ZyMos 9 │ their presense. Trident 10─┘ 8514/A 11 -checks for HDILOAD.EXE only If a VESA BIOS is present, then add 128 to errorlevels. Note: The BIOS based id strings were obtained from Ralf Brown's PD DOS Interrupts list (INTER32). The register level chipset tests were obtained through various sources, including John Bridges' VGAKIT 5.0, and Andrew Rossmann's INFOPLUS 1.55 source code. However, both gentlemen appear to have gotten their info through the book "Advanced Programmer's Guide to Super VGAs", by George Sutty and Steve Blair. So lay credit wherever you like. \ noSVGA equ 0 mov bl, noSVGA ;initially assume no SVGA push es ;save current ES segment mov ax, 0C000h ;set ES to VBIOS mov es, ax ; segment (C000h) ; ;now testing for ATI chipset ; .data ATIid db "761295520" idlen = $-ATIid ATI equ 1 .code mov di, 31h ;id string offset in ATI VBIOS mov si, offset ATIid mov cx, idlen repe cmpsb ;comp each byte, exit if not matched jne noATI mov bl, ATI ;ATI was found jmp endSVGAtests noATI: ; ;now testing for Ahead chipset ; .data AHEADid db "AHEAD" idlen = $-AHEADid AHEAD equ 2 .code mov di, 25h ;id string offset in AHEAD VBIOS mov si, offset AHEADid mov cx, idlen repe cmpsb ;comp each byte, exit if not matched jne noAHEAD mov bl, AHEAD ;AHEAD was found jmp endSVGAtests noAHEAD: ; ;now testing for Paradise/WD chipset ; .data PDISEid db "VGA=" idlen = $-PDISEid PDISE equ 3 .code mov di, 7dh ;id string offset in Pdise VBIOS mov si, offset PDISEid mov cx, idlen repe cmpsb jne noPDISE mov bl, PDISE ;Paradise was found jmp endSVGAtests noPDISE: ; ;now testing for OAK chipset ; .data OAKid db "OAK VGA" idlen = $-PDISEid OAK equ 4 .code mov di, 8 ;id string offset in OAK VBIOS mov si, offset OAKid mov cx, idlen repe cmpsb jne noOAK mov bl, OAK ;OAK was found jmp endSVGAtests noOAK: ; ;now testing for Genoa chipset ; ;the installation check for Genoa video adapters is the ;signature 77h XXh 99h 66h at C000h:0037h, where XXh is ; 00h for Genoa 6200/6300 ; 11h for Genoa 6400/6600 ; 22h for Genoa 6100 ; 33h for Genoa 5100/5200 ; 55h for Genoa 5300/5400 ; .data GENOAid db 77h,00h,99h,66h idlen = $-GENOAid GENOA equ 5 .code mov di, 37h ;id string offset in OAK VBIOS mov si, offset GENOAid mov cx, idlen repe cmpsb pushf ;save flags cmp cx, idlen-2 ;did mismatch occur after 2nd byte? je contGENOA ;yes? continue test at next byte popf ;restore flags jmp discontGENOA contGENOA: popf ;restore flags repe cmpsb ;continue tests where it left off discontGENOA: jne noGENOA mov bl, GENOA jmp endSVGAtests noGENOA: ; ;The following chipsets require register tests, and cannot be ; identified through the BIOS: ; ;test for CIRRUS chipset (register) ; call CIRRUStest cmp bl, 0 ;if BL=0, Cirrus wasn't found jne endSVGAtests ; ;test for ZyMos chipset (register) ; call ZYMOStest cmp bl, 0 ;C&T was not found jne endSVGAtests ; ;test for TSENG chipset (register) ; call TSENGtest cmp bl, 0 ;Tseng was not found jne endSVGAtests ; ;test for Trident chipset (register) ; call TridentTest cmp bl, 0 ;Trident wasn't found jne endSVGAtests call Test8514 cmp bl, 0 jne endSVGAtests ;8514/A wasn't found ; ;test for C&T chipset (register) ; ;Note: the C&T test routine has been moved to the end, because ; it seems to cause the most lockups. ; call CHIPStest endSVGAtests: ; ;test to see if VESA BIOS is installed ; .data VESAbuf db 256 dup(?) ;VESA information buffer .code pop es mov ax, 4f00h mov di, offset VESAbuf int 10h ;VESA: get SVGA info cmp ax, 004fh ;if VESA installed this should work jne noVESA ; ; If VESABIT of the record, SVGATYPE, is set, then a VESA ; BIOS was found. The rest of the record just records what ; type of SVGA was found, regardless of VESA. ; svgatype record vesabit:1,svgabits:7 or bl, mask vesabit ;turn on VESAbit, in ext code noVESA: ret CIRRUStest proc comment * Purpose: Register-level test for CIRRUS chipset Entry: BH=current normal DCC Return: BL=SVGA code * CIRRUS equ 6 push bx ;save BH mov dx, 3B4h;assume DX=mono VGA selection port cmp bh, 8 ;if BH=8, color; BH=7, mono je color_cirrus add dx, 020h;if color, add 20h to select port addr color_cirrus: mov al, 0Ch ;Start Addr High register out dx, al inc dx ;DX=data port in al, dx ;read register mov ah, al ;save xchg al, ah ;swap back push ax ;save port value push dx ;save port addr xor al, al out dx, al ;zero Start Addr High reg dec dx ;back to selection port mov al, 1Fh out dx, al ;select special Cirrus ID reg inc dx ;back to data port in al, dx ;read ID reg value mov ah, al ;save it in AH mov bh, al ;save again in BH mov dx, 3c4h;addr of special seq'ncr/ext'ns select port mov al, 6 ;extensions control reg mov cl, 4 ;get ready to swap the nibbles in AX ror bh, cl ;nibble swap computes ext reg disable val mov ax, bx out dx, ax ;disable extensions inc dx ;seq/ext data port in al, dx ;read back enable flag or al, al ;disabled? jnz noCIRRUS dec dx ;seq/ext select port mov bh, al ;save AL mov al, 6 ;extensions control reg out dx, al inc dx mov al, ah ;restore ID reg value out dx, al ;reenable ext regs in al, dx ;read back ext reg cmp al, 1 ;enabled? jne noCIRRUS ror bh, cl ;nibble swap to compute enable ext reg val dec dx mov ax, bx out dx, ax ;ext enable inc dx in al, dx cmp al, 1 jne noCIRRUS mov bl, CIRRUS ;CIRRUS was found noCIRRUS: pop dx dec dx ;point select reg pop ax out dx, ax ;restore to orig state pop ax ;restore BH mov bh, ah ret endp CHIPStest proc comment * Purpose: Register-level test for C&T VGA chipset Entry: BH=current normal DCC Return: BL=SVGA code Note: This particular test appears to lockup my system, with an ATI VGAWonder card installed, after the first port write. I have no idea if this lockup is due to the presence of the ATI or some other component in my motherboard. So be forewarned: always do the ATI test first, which is safely BIOS-based, before you do this test. In fact you might want to save this test for the last of all the tests you do. * CHIPS equ 7 ;place VGA in setup mode cli mov dx,46e8h ;address of setup control reg in al,dx or al,10h ;turn on setup bit out dx,al ;go to setup mode ;enable extended register bank mov dx,103h ;extended reg address in al,dx or al,80h ;turn enable bit on out dx,al ;read global ID mov dx,104h ;global ID reg in al,dx mov ah,al ;save ;place vga in normal mode mov dx,46e8h in al,dx and al,03fh out dx,al sti ;read version extended register mov dx,3d6h mov al,0 out dx,al ;select version register inc dx in al,dx cmp ah,5ah ;check for CTI ID jne notcti and al,0f0h ;adjust chip id shr al,1 shr al,1 shr al,1 shr al,1 cmp al,2 ;only 0, 1 and 3 are good je notcti cmp al,4 jge notcti cmp al,3 je notcti mov bl, CHIPS ;return SVGA info notcti: ret endp TSENGtest proc comment * Purpose: Register-level test for Tseng VGA chipset Entry: BH=current normal DCC Return: BL=SVGA code * TSENG equ 8 mov dx,3cdh ;page select reg in al,dx mov ah,al ;save and al,0c0h ;save some bits or al,55h ;test value one out dx,al ;write it in al,dx cmp al,55h ;same? jne nottseng mov al,0aah ;test value two out dx,al in al,dx cmp al,0aah ;same jne nottseng mov al,ah ;restore original settings out dx,al mov al,1 end_tsengck: mov bl, TSENG ;found a TSENG nottseng: ret endp ZYMOStest proc comment * Purpose: Register-level test for ZyMos VGA chipset Entry: BH=current normal DCC Return: BL=SVGA code * ZyMos equ 9 mov dx,3c4h ;extended reg bank mov al,0bh ;version reg out dx,al inc dx in al,dx ;get version and al,0fh cmp al,2 jne end_zymosck ;not found mov bl, ZyMos ;found one end_zymosck: ret endp TridentTest proc comment * Purpose: Register level test for Trident VGA chipset Entry: BH=current normal DCC Return: BL=SVGA code Note: -Thanks to John Olson, of Fidonet 1:106/888, of the Fidonet 80XXX assembly language echo, who supplied this routine from "Programmer's Guide to the EGA and VGA Cards", by Richard F. Ferraro. * Trident equ 10 MOV DX,3C4H MOV AL,0EH ; Read mode control #1 Register OUT DX,AL INC DX IN AL,DX ; Read old value XOR AL,2 PUSH AX MOV AL,0 ; Write new value bit 1=0, all ;other bits =0 OUT DX,AL IN AL,DX ; Read new value AND AL,0FH CMP AL,2 ; Check for Trident POP AX ; Old value OUT DX,AL ; Restore old value JNZ NOT_T mov bl, Trident ;found one not_t: ret endp Test8514 proc comment * Purpose: Installation check for 8514/A's HDILOAD.EXE Entry: BH=current normal DCC Return: BL=SVGA code AX,CX,DX destroyed * _8514 equ 11 ; ;If HDILOAD installed then CX and/or DX will be modified ; as CX:DX->function entry point array ; mov ax, 105h mov cx, 0 mov dx, 0 int 7Fh ;installation check cmp cx, 0 ;if CX didn't change je no8514 mov bl, _8514 no8514: ret endp endp findEGA proc comment * Purpose: To find an EGA * mov ah, 12h mov bx, 0FF10h int 10h ;for EGA BIOS+ only cmp bh, 0FFh ;if BH remains unchanged je endEGAtest ; then EGA BIOS not installed cmp bh, 0 ;BH=0, if color EGA jne EGAmono mov [egatype], mask colorfound mov bl, cEGA ;EGA w/ color disp mov dx, 3D4h ;color port addr call determine_subsystem jmp endEGAtest EGAmono: mov [egatype], mask monofound mov bl, mEGA ;EGA w/ mono disp mov dx, 3B4h ;mono port addr call determine_subsystem endEGAtest: ret endp findCGA proc comment * Purpose: To find a CGA * test [egatype], mask colorfound ;is color EGA present? jne endCGAtest ;yes, then skip test mov dx, 3D4h ;DX=CGA 6845 CRTC port addr call find6845 jc endCGAtest ;didn't find CGA mov bl, CGA ;ie. found CGA call determine_subsystem endCGAtest: ret endp findMono proc comment * Purpose: To find a Mono adapter * test [egatype], mask monofound ;is mono EGA present? jne EndMonotest ;yes, then skip test mov dx, 3B4h ;DX=Mono 6845 CRTC port addr call find6845 jc EndMonoTest ;didn't find MDA ; ;We've found a mono adapter, now it's time to find out ; if it's a Hercules-compatible monographics adapter. ; mov bl, MONO ;found MDA call determine_subsystem jc mono_is_2nd ;MDA was 2nd system call findHGC ;is 1st a Herc? mov [ext0type], bl jmp EndMonoTest mono_is_2nd: call findHGC ;is 2nd a Herc? mov [ext1type], bl EndMonoTest: ret endp findHGC proc comment * Purpose: To determine if MDA found is also a Herc of some sort Enter: nothing Return: BL=Herc type * NoHerc equ 0 ;no Hercules Herc equ 1 ;regular Hercules HercP equ 2 ;Hercules Plus HercIC equ 3 ;Hercules InColor comment \ Hercs are identified from normal MDA by bit 7, vertical sync, on 6845 Status Port which is changeable only on Hercs. Hercs are identified from each other with bits 4-6 in Status Port. On an regular Herc, they are 000b, on Herc+, they are 001b, and on InColor, they are 101b. Each bit is kept track of in the record, HGCStatus. \ HGCStatus record vsync:1,HGCid:3,miscbits:4 mov dx, 3BAh ;status port in al, dx and al, mask vsync mov ah, al ;store current vsync status in AH mov cx, 8000h ;loop 32768 times teststatusbit: in al, dx and al, mask vsync cmp ah, al loope teststatusbit ;keep looping as long as they are equal jne HercIDs ;if vsync changed, is a Herc mov bl, NoHerc ;was not a Herc jmp EndHercTests HercIDs: in al, dx ;read status port again and al, mask HGCid ;mask all but bits 4-6 cmp al, HGCStatus <0,001b,0> ;indicates HGC+ je isPlus mov bl, Herc ;is a regular Herc, for now cmp al, HGCStatus <0,101b,0> ;indicates InColor jne EndHercTests ;didn't find InColor mov bl, HercIC ;is an InColor jmp EndHercTests isPlus: mov bl, HercP ;is a Herc Plus (Ramfonts) EndHercTests: ret endp determine_subsystem proc comment * Purpose: To determine if currently tested subsystem is primary or secondary Entry: BL=subsystem DCC value to input in memory DX=port address to compare against Return: CF clear if primary system, set if secondary * push ax ;save AX push es ;save ES mov ax, 40h ;set ES to mov es, ax ; BIOS data segment mov ax, es:[63h] ;AX=active Vid CRTC base addr cmp ax, dx ;is current = default? pop es ;restore ES pop ax ;restore AX jne _2ndsystem ;if not default, must be 2nd subsystem mov [std0type], bl ;store as 1st system clc ;is primary, so clear CF jmp end_det_sys _2ndsystem: mov [std1type], bl ;store as 2nd system stc ;is secondary, so set CF end_det_sys: ret endp find6845 proc comment * Purpose: Detect if a 6845-compatible CRTC controller is present at port address given in DX Entry: DX=CRTC base port address to test Return: CF clear if successful, set if not * push dx push ax mov al, 0Fh out dx, al ;select 6845 reg 0Fh (cursor low) inc dx in al, dx ;AL=current cursor low val mov ah, al ;save AL in AH mov al, 66h ;AL=set some arbitrary val out dx, al ;write to 6845 mov cx, 100h loop $ ;loop 100h times in al, dx xchg ah, al ;AH=returned value ;AL=original value out dx, al ;restore original value cmp ah, 66h ;did 6845 respond? je end6845 stc ;set CF if 6845 not there end6845: pop ax pop dx ret endp write_msg proc comment * Purpose: To display video adapter information to Stdout, and return an errorlevel based on command line parameters. * .data CRLF equ 13,10,"$" copyright db "VIDTYPE v1.1 (c) 1992, Yousuf J. Khan",CRLF std_msg db "Standard video information:",CRLF ext_msg db "Extended video information:",CRLF vid1msg db "Primary video subsystem:",CRLF vid2msg db "Secondary video subsystem:",CRLF ;Standard video adapter types (based on VGA BIOS DCCs) DCC00 db "no display",CRLF DCC01 db "monochrome adapter w/ monochrome display",CRLF DCC02 db "CGA w/ color display",CRLF DCC03 db "reserved",CRLF DCC04 db "EGA w/ color display",CRLF DCC05 db "EGA w/ monochrome display",CRLF DCC06 db "PGA w/ color display",CRLF DCC07 db "VGA w/ monochrome analog display",CRLF DCC08 db "VGA w/ color analog display",CRLF DCC09 db "reserved",CRLF DCC0A db "MCGA w/ digital color display",CRLF DCC0B db "MCGA w/ monochrome analog display",CRLF DCC0C db "MCGA w/ color analog display",CRLF DCCFF db "unknown display type",CRLF stdmsgtbl dw DCC00 dw DCC01 dw DCC02 dw DCC03 dw DCC04 dw DCC05 dw DCC06 dw DCC07 dw DCC08 dw DCC09 dw DCC0A dw DCC0B dw DCC0C dw DCCFF ;Extended video adapter types (various Hercs & Super VGAs) HG equ "Hercules " SV equ "Super VGA: " EXT00 db "no extended info available",CRLF HGC00 db HG,"standard",CRLF HGC01 db HG,"Plus (Ramfonts)",CRLF HGC02 db HG,"InColor",CRLF HGCmsgtbl dw EXT00 ;no Herc dw HGC00 dw HGC01 dw HGC02 VGA00 db SV,"ATI",CRLF VGA01 db SV,"AHEAD",CRLF VGA02 db SV,"Paradise",CRLF VGA03 db SV,"Oak",CRLF VGA04 db SV,"Genoa",CRLF VGA05 db SV,"Cirrus",CRLF VGA06 db SV,"Chips & Tech",CRLF VGA07 db SV,"TSENG",CRLF VGA08 db SV,"ZyMos",CRLF VGA09 db SV,"Trident TVGA",CRLF VGA10 db SV,"8514/A",CRLF VGAmsgtbl dw EXT00 ;no SVGA dw VGA00 dw VGA01 dw VGA02 dw VGA03 dw VGA04 dw VGA05 dw VGA06 dw VGA07 dw VGA08 dw VGA09 dw VGA10 spaces db " $" ;three space indentation VESAmsg db "VESA BIOS present",CRLF .code DOSMSG macro msg_offset mov ah, 9 mov dx, offset msg_offset int 21h endm TYPEmsg macro base, index xor bx, bx add bl, [index] ; ;mask out VESA bit in "svgatype" record ; both forms of the AND below are the same ; ; and bl, mask svgabits ;mask bottom 7 bits, or and bl, not mask vesabit ; don't mask 8th bit mov si, bx shl si, 1 ;mult offsets by 2 mov bx, offset base mov dx, [bx][si] mov ah, 9 int 21h endm INDENT macro num ; ;puts indentations in text printed to screen ; rept num mov dx, offset spaces mov ah, 9 int 21h endm endm DOSMSG copyright INDENT 1 DOSMSG vid1msg INDENT 2 DOSMSG std_msg INDENT 3 TYPEmsg stdmsgtbl, std0type INDENT 2 DOSMSG ext_msg INDENT 3 cmp [std0type], 1 ;is it MDA? je extmono1 ;yes, it's MDA TYPEmsg vgamsgtbl, ext0type mov bl, ext0type and bl, mask vesabit ;was VESA bit set? je _2nd_vid_adapter ;no VESA INDENT 3 DOSMSG VESAmsg ;display VESA message jmp _2nd_vid_adapter extmono1: TYPEmsg hgcmsgtbl, ext0type _2nd_vid_adapter: INDENT 1 DOSMSG vid2msg INDENT 2 DOSMSG std_msg INDENT 3 TYPEmsg stdmsgtbl, std1type INDENT 2 DOSMSG ext_msg INDENT 3 cmp [std1type], 1 ;is it MDA or VGA? je extmono2 ;it's MDA TYPEmsg vgamsgtbl, ext1type mov bl, ext1type and bl, mask vesabit ;was VESA bit set? je end_display ;no VESA INDENT 3 DOSMSG VESAmsg ;display VESA message jmp end_display extmono2: TYPEmsg hgcmsgtbl, ext1type end_display: call return_errorlevel;return errorlevel ; mov al, [std0type] ;return errorlevel ret endp return_errorlevel proc comment * Purpose: To scan command-line for errorlevel return parameters eg: vidtype vidtype e vidtype 2 vidtype e2 vidtype 2E Command-line parameters: none errorlevel based on prim video subsys "e" errorlevel based on prim ext video code "2" errorlevel based on sec video subsys both errorlevel based on sec ext video code * .data cmdln_params record secondary:1, extended:1 cmdflags cmdln_params <0,0> .code ; ;start parsing the command line ; lookfor macro char mov al, char mov di, 81h repne scasb endm mov si, 80h ;point to command-line in PSP lodsb ;get length of cmd-line in AL ; ;looking for little "e" ; push ds pop es ;ES=DS xor cx, cx mov cl, al ;number of interations push cx ;save CX lookfor "e" jne SeekBigE or [cmdflags], mask extended ;set the flag jmp SeekTwo ;start looking for "2" SeekBigE: ; ;looking for big "E" ; pop cx ;restore CX push cx ;save it again lookfor "E" jne SeekTwo or [cmdflags], mask extended ;set the flag SeekTwo: ; ;looking for "2" ; pop cx ;restore CX lookfor "2" jne send_err00 or [cmdflags], mask secondary ;set the flag send_err00: cmp [cmdflags], cmdln_params <0,0> ;neither flag set jne send_err01 mov al, [std0type] jmp endret_err send_err01: cmp [cmdflags], cmdln_params <0,1> ;ext flag set jne send_err10 mov al, [ext0type] jmp endret_err send_err10: cmp [cmdflags], cmdln_params <1,0> ;sec flag set jne send_err11 mov al, [std1type] jmp endret_err send_err11: ;both ext and sec flags set mov al, [ext1type] endret_err: ret endp end start