Pete's QBASIC Site

Assembly Answer

2011-04-05T00:10:49-05:00

On the internal server error, either try reposting, or host it somewhere else, and link to it.
Do you need some free hosting space recommendations?
I can PM you websites that are easy to use & free with lots of perks.

~Kiyote!

Statistics: Posted by Kiyotewolf — Tue Apr 05, 2011 12:10 am

I see what your saying here

2011-04-04T21:54:03-05:00

I tried making a big post but see what you are saying and I received Internal server error.

Statistics: Posted by TRANERAECK — Mon Apr 04, 2011 9:54 pm

Assembly Answer

2011-04-04T17:33:41-05:00

"but it is limited in some ways seeing as it is my personal font routine which I made for my own needs. "

Can't do everything with everything.
Did you write the ASM in the routine?
This is slick. This is very slick! I'd like to try using this on my own *.BAS's.
I've always been on the outside looking in when it came to ASM on an IBM compatible.
On an 6502, I can program it in ASM like you wouldn't believe. I'm a whiz, or at least I know enough to be able to read and write and modify code.
On 8088 (meaning 80686 now..), I've only just a few months ago begun to understand a few more ASM concepts. Mike Chambers has been doing an 8086/80186 Fake86 emulator, and talking a bit to him has made me a bit braver and a bit wiser on just the simple hows and whys.

Yesterday I was even typing in actual opcode names in DEBUG to get the HEX values back out.
Not writing code mind you, just finding out which OPCODE went with which machine code.

I guess what really grinds my gears, is the fact that I can't ever seem to find a piece of paper that has the 8086 (yes I mean simply the 8086 & or 8088) opcodes, listed, and then how many operands they use per operation mode, so I could sit there and write machine code (HEX values to plug into a QBasic program natively) by hand with a pencil.
I'd try just writing in DEBUG, but how do you take a script in ASM written for MASM or TASM and then dumb it down and strip it of the markings, so that DEBUG accepts it??
I don't know what legal syntax DEBUG has for entering ASM, I mean the exact grammer you need to use, so I can successfully translate some MASM ASM scripts into plain vanilla assembly language

MOV AX,0000

type instructions. I hang up when I get to jump points which are labels

JUMPPOINT;

and don't know how to replace those with the proper OPCODE and the jump vector in the HEX right after.

~Kiyote!

Statistics: Posted by Kiyotewolf — Mon Apr 04, 2011 5:33 pm

Assembly Answer

2011-04-04T16:20:28-05:00

Here is a font routine I use for some of my good programs. It uses a font file that is only about 1kb and it includes the font data for characters 32 - 126 and in the font file also included the machine code to display it on screen quickly.

It is much quicker then the BIOS font and more flexible with coordinates, but it is limited in some ways seeing as it is my personal font routine which I made for my own needs.

You need the 1kb font file:
http://qbasic.orgfree.com/FONT.F

Code:

DEFINT A-ZDECLARE SUB printf (x, y, s$)DIM SHARED font(282) AS LONGDEF SEG = VARSEG(font(0))BLOAD "font.f", VARPTR(font(0))SCREEN 12LINE (50, 50)-(250, 250), 15, BFFOR i = 0 TO 450 STEP 15printf 0, i, "abcdefghijklmnopqrsSDGASAF~!@#$%#@%^43562345@!#$ HELLO WORLD!!!!!!!!!!!"NEXTSLEEPSUB printf (x, y, s$)CALL absolute(BYVAL x, BYVAL y, BYVAL VARPTR(s$), SEG font(0), VARPTR(font(262)))END SUB

Statistics: Posted by Guest — Mon Apr 04, 2011 4:20 pm

Assembly Answer

2011-04-04T16:09:26-05:00

Does your *.COM file packer have to alter how the *.COM file terminates?
I am not fluent in 8086 (80686) ASM, and I've seen various exit, RETF commands RETN commands, that are the last thing before exiting a *.COM vs the last thing before exiting a ASM routine in QB, especially if passing variables.

Usually there's a RETF two bytes after, that designate how many bytes to return on the stack when exiting.

Does your packer modify anything when it's converting it to a QB source file?

~Kiyote!

It does not modify the com file, but this requires that the RETF is included in the com file and that you yourself know how many bytes to return to stack, etc.

I'm going to post one of my programs that BLOADs a raw binary file and that excutes it with CALL ABSOLUTE.

Statistics: Posted by Guest — Mon Apr 04, 2011 4:09 pm

Assembly Answer

2011-04-04T01:19:42-05:00

Does your *.COM file packer have to alter how the *.COM file terminates?
I am not fluent in 8086 (80686) ASM, and I've seen various exit, RETF commands RETN commands, that are the last thing before exiting a *.COM vs the last thing before exiting a ASM routine in QB, especially if passing variables.

Usually there's a RETF two bytes after, that designate how many bytes to return on the stack when exiting.

Does your packer modify anything when it's converting it to a QB source file?

~Kiyote!

Statistics: Posted by Kiyotewolf — Mon Apr 04, 2011 1:19 am

Assembly Answer

2011-04-04T01:15:35-05:00

Wow you're good! These are awesome!

~Kiyote!

Statistics: Posted by Kiyotewolf — Mon Apr 04, 2011 1:15 am

Assembly Answer

2011-04-04T01:04:04-05:00

this is great. I have myself a utility that converts my assembled com files into compact QB code using call absolute.

Code:

DIM a AS LONGDIM i AS INTEGERCLSON ERROR GOTO 1f$ = COMMAND$IF f$ = "" THEN  PRINT "syntax: asm.exe arrayname pathto.com"  SYSTEMEND IFf$ = LTRIM$(RTRIM$(f$))FOR i = 1 TO LEN(f$)  IF MID$(f$, i, 1) = " " THEN EXIT FOR  s$ = s$ + MID$(f$, i, 1)NEXTs$ = LCASE$(s$)l = LEN(f$)f$ = RIGHT$(f$, l - i)i = 0OPEN f$ FOR BINARY AS #1  DO    GET #1, , a    i = i + 1  LOOP UNTIL EOF(1)CLOSEPRINT "dim " + s$ + "(" + LTRIM$(STR$(i - 1)) + ") as long"i = 0OPEN f$ FOR BINARY AS #1  DO    GET #1, , a    PRINT s$ + "(" + LTRIM$(STR$(i)) + ")=" + "&H" + HEX$(a) '+ CHR$(10)    i = i + 1  LOOP UNTIL EOF(1)CLOSESYSTEM1 PRINT "error"SYSTEM

Here is my personal mouse routine that I use in most of my programs. It even works with QB64.

Code:

DIM mb AS INTEGER, mx AS INTEGER, my AS INTEGERDIM a(7) AS LONGa(0) = &H8BE58955a(1) = &H48B0C76a(2) = &H768B33CDa(3) = &H8B1C890Aa(4) = &HC890876a(5) = &H8906768Ba(6) = &H8CA5D14DEF SEG = VARSEG(a(0))SCREEN 12CALL absolute(1, mb, mx, my, VARPTR(a(0)))DO   CALL absolute(3, mb, mx, my, VARPTR(a(0)))   LOCATE 1, 1   PRINT mb, mx, myLOOP UNTIL INP(&H60) = 1SYSTEM

This is the program I use to find my way around in DOS

Code:

DEFINT A-ZTYPE dtatype   reserved AS STRING * 21   a AS STRING * 1   time AS INTEGER   date AS STRING * 2   size AS LONG   n AS STRING * 13END TYPETYPE filetype   n AS STRING * 13   a AS STRING * 1END TYPEDIM n(19) AS LONGn(0) = &H1EE58955n(1) = &HB80656C5n(2) = &H21CD1A00n(3) = &H4CA5D1Fn(5) = &H8BE58955n(6) = &H4E8B0656n(7) = &HA768B08n(8) = &H21CD048Bn(9) = &HCA5D0489n(10) = &H6n(11) = &H8BE58955n(12) = &H33CD0C46n(13) = &H890A768Bn(14) = &H8768B1Cn(15) = &H4103E9C1n(16) = &H768B0C89n(17) = &H3EAC106n(18) = &H5D148942n(19) = &H8CADEF SEG = VARSEG(n(0))DIM f(500) AS filetypeDIM dta AS dtatypeCALL absolute(SEG dta, VARPTR(n(0)))d$ = "c:\"d$ = "d:\"1 CLSCOLOR 14VIEW PRINT 1 TO 25FOR i = 1 TO 23   LOCATE i, 20   PRINT STRING$(10, 25 + (i <= 11))NEXTCALL absolute(BYVAL 1, mb, mx, my, VARPTR(n(11)))j = 0ax = &H4E00e$ = d$ + "*.*" + CHR$(0)CALL absolute(ax, BYVAL 16, BYVAL SADD(e$), VARPTR(n(5)))FOR i = 0 TO UBOUND(f)   ax = &H4F00   CALL absolute(ax, 0, 0, VARPTR(n(5)))   IF (ax AND &HF) <> 0 THEN EXIT FOR   file$ = LEFT$(dta.n, INSTR(dta.n, CHR$(0)) - 1)   f(i).n = file$   ' PRINT file$, dta.date   f(i).a = dta.a   ' SLEEPNEXTn = i' SYSTEMDO   CALL absolute(BYVAL 3, mb, mx, my, VARPTR(n(11)))   LOCATE 1, 1   FOR i = 0 + j TO 22 + j   IF i < n THEN PRINT CHR$(-((i - j + 1) = my) * 16) + CHR$(92 * -(f(i).a = CHR$(16))) + f(i).n + CHR$(-((i - j + 1) = my) * 17)   NEXT   LOCATE 25   IF (my + j - 1) < n THEN PRINT d$ + f(my + j - 1).n;   IF mb = 1 THEN      IF mx < 17 AND f(my + j - 1).a = CHR$(16) AND (my + j - 1) < n THEN         DO UNTIL mb = 0            CALL absolute(BYVAL 3, mb, mx, my, VARPTR(n(11)))         LOOP         d$ = d$ + RTRIM$(f(my + j - 1).n) + "\"         GOTO 1      ELSE         t! = TIMER         j = j + (mx > 19 AND mx < 30) * (my > 11) AND ((j + 22) < n)         j = j - (mx > 19 AND mx < 30) * (my < 11) AND (j > 0)2 IF TIMER < (t! + .1) THEN 2      END IF   END IFLOOP UNTIL INP(&H60) = 1SYSTEM

Statistics: Posted by Guest — Mon Apr 04, 2011 1:04 am

Assembly Answer

2011-04-03T21:22:15-05:00

NOTE: if you run the program in a DOS Window, you have to hit ALT-ENTER to go FULLSCREEN to see the effect of the program.
Otherwise it will override the blink function of a DOS text screen, and you won't see the effects of the program running.

Press CTRL-BREAK or CTRL-C or CTRL-SCROLLLOCK to exit the program, which ever key combination your keyboard requires.

~Kiyote!

Statistics: Posted by Kiyotewolf — Sun Apr 03, 2011 9:22 pm

Assembly Answer

2011-04-03T21:20:17-05:00

Code:

'Example of CALL ABSOLUTE and ASM languageDEFINT A-ZTYPE REGTYPE 'Machine language interface     AX    AS INTEGER     BX    AS INTEGER     CX    AS INTEGER     DX    AS INTEGER     BP    AS INTEGER     SI    AS INTEGER     DI    AS INTEGER     FLAGS AS INTEGER     DS    AS INTEGER     ES    AS INTEGEREND TYPEDIM SHARED REGS AS REGTYPEDECLARE SUB INTERRUPT (INTNUM%, REGS AS REGTYPE)'Other SUBs and FUNCTIONsDECLARE SUB BackIntens (Setting%)REDIM SHARED INTRPT(1 TO 50) 'Machine language interfaceDEF SEG = VARSEG(INTRPT(1))ADDRESS = VARPTR(INTRPT(1))OPEN "c:\interupt.bin" FOR BINARY AS #1DIM dummy AS STRING * 1FOR i = 0 TO 99    READ a    POKE ADDRESS + i, a    dummy = CHR$(a)    PUT #1, , dummyNEXTCLOSE #1Flash = 0SCREEN 0WIDTH 80, 25COLOR 7, 0CLSBackIntens Flash 'Make sure colors flashDEF SEG = &HB800FOR x = 0 TO 15  FOR y = 0 TO 15    POKE x * 2 * 2 + y * 160, x + y * 16    POKE x * 2 * 2 + y * 160 + 1, x + y * 16  NEXT yNEXT xBackIntensTest = -1IF BackIntensTest THEN  Flash = -1  FOR x = 0 TO 15    FOR y = 0 TO 15      LOCATE y + 1, x * 2 + 1      COLOR x - 16 * Flash, y      PRINT CHR$(254);      COLOR x, y      PRINT CHR$(254);    NEXT  NEXT  DO    WHILE INKEY$ = "": WEND    BackIntens -1    WHILE INKEY$ = "": WEND    BackIntens 0  LOOPEND IFEND'Machine code for interrupt calling routine:DATA 85                  : 'PUSH BPDATA 139, 236            : 'MOV  BP, SPDATA 86                  : 'PUSH SIDATA 87                  : 'PUSH DIDATA 30                  : 'PUSH DSDATA 139, 118, 6         : 'MOV  SI, WORD PTR [BP+6]DATA 139, 4              : 'MOV  AX, WORD PTR [SI]DATA 139, 92, 2          : 'MOV  BX, WORD PTR [SI+2]DATA 139, 76, 4          : 'MOV  CX, WORD PTR [SI+4]DATA 139, 84, 6          : 'MOV  DX, WORD PTR [SI+6]DATA 139, 108, 8         : 'MOV  BP, WORD PTR [SI+8]DATA 139, 124, 12        : 'MOV  DI, WORD PTR [SI+12]DATA 142, 68, 18         : 'MOV  ES, [SI+18]DATA 255, 116, 10        : 'PUSH WORD PTR [SI+10]DATA 131, 124, 18, 255   : 'CMP  WORD PTR [SI+18],-1DATA 117, 2              : 'JNZ  LABEL1DATA 30                  : 'PUSH DSDATA 7                   : 'POP  ES                         : 'LABEL1:DATA 131, 124, 16, 255   : 'CMP  WORD PTR [SI+16],-1DATA 116, 3              : 'JZ   LABEL2DATA 142, 92, 16         : 'MOV DS, [SI+16]                         : 'LABEL2:DATA 94                  : 'POP  SIDATA 205, 33             : 'INT 33DATA 85                  : 'PUSH BPDATA 139, 236            : 'MOV  BP, SPDATA 30                  : 'PUSH DSDATA 86                  : 'PUSH SIDATA 142, 94, 2          : 'MOV DS, [BP+2]DATA 139, 118, 14        : 'MOV SI, WORD PTR [BP+14]DATA 137, 4              : 'MOV WORD PTR [SI], AXDATA 137, 92, 2          : 'MOV WORD PTR [SI+2], BXDATA 137, 76, 4          : 'MOV WORD PTR [SI+4], CXDATA 137, 84, 6          : 'MOV WORD PTR [SI+6], DXDATA 143, 68, 10         : 'POP WORD PTR [SI+10]DATA 143, 68, 16         : 'POP WORD PTR [SI+16]DATA 143, 68, 8          : 'POP WORD PTR [SI+8]DATA 137, 124, 12        : 'MOV WORD PTR [SI+12], DIDATA 140, 68, 18         : 'MOV WORD PTR [SI+18], ESDATA 156                 : 'PUSHFDATA 143, 68, 14         : 'POP WORD PTR [SI+14]DATA 95                  : 'POP DIDATA 95                  : 'POP DIDATA 94                  : 'POP SIDATA 93                  : 'POP BPDATA 202, 2, 0           : 'RETF 2SUB BackIntens (Setting)  REGS.AX = &H1003  IF Setting THEN    REGS.BX = 0 'High intensity background  ELSE    REGS.BX = 1 'Flashing foreground  END IF  CALL INTERRUPT(&H10, REGS)END SUBSUB INTERRUPT (INTNUM, REGS AS REGTYPE)  DEF SEG = VARSEG(INTRPT(1))'Point to buffer segment  ADDRESS = VARPTR(INTRPT(1)) '  and offset  POKE ADDRESS + 51, INTNUM   'Replace INT number in code  CALL ABSOLUTE(REGS, ADDRESS) 'Call assembler routine.END SUB

The above and the below, are two different worlds.
Your effort is very clean & intelligent, but you missed a couple points on getting it working right.

Below is the partial dissasembly of the routine that was loaded into QBasic and DOS's conventional memory.

Your example, would have us copy both into the same text file, then hit RUN in QBasic. It would not work that way.

THE ABOVE EXAMPLE IS COMPLETE, WORKING, so you CAN copy / paste into QBasic (NOT QUICKBASIC v4.5), and run it.

Code:

C:\>debug interupt.bin-u5E17:0100 55            PUSH    BP5E17:0101 8BEC          MOV     BP,SP5E17:0103 56            PUSH    SI5E17:0104 57            PUSH    DI5E17:0105 1E            PUSH    DS5E17:0106 8B7606        MOV     SI,[BP+06]5E17:0109 8B04          MOV     AX,[SI]5E17:010B 8B5C02        MOV     BX,[SI+02]5E17:010E 8B4C04        MOV     CX,[SI+04]5E17:0111 8B5406        MOV     DX,[SI+06]5E17:0114 8B6C08        MOV     BP,[SI+08]5E17:0117 8B7C0C        MOV     DI,[SI+0C]5E17:011A 8E4412        MOV     ES,[SI+12]5E17:011D FF740A        PUSH    [SI+0A]-u5E17:0120 837C12FF      CMP     WORD PTR [SI+12],-015E17:0124 7502          JNZ     01285E17:0126 1E            PUSH    DS5E17:0127 07            POP     ES5E17:0128 837C10FF      CMP     WORD PTR [SI+10],-015E17:012C 7403          JZ      01315E17:012E 8E5C10        MOV     DS,[SI+10]5E17:0131 5E            POP     SI5E17:0132 CD21          INT     215E17:0134 55            PUSH    BP5E17:0135 8BEC          MOV     BP,SP5E17:0137 1E            PUSH    DS5E17:0138 56            PUSH    SI5E17:0139 8E5E02        MOV     DS,[BP+02]5E17:013C 8B760E        MOV     SI,[BP+0E]5E17:013F 8904          MOV     [SI],AX-u5E17:0141 895C02        MOV     [SI+02],BX5E17:0144 894C04        MOV     [SI+04],CX5E17:0147 895406        MOV     [SI+06],DX5E17:014A 8F440A        POP     [SI+0A]5E17:014D 8F4410        POP     [SI+10]5E17:0150 8F4408        POP     [SI+08]

[/quote]

Statistics: Posted by Kiyotewolf — Sun Apr 03, 2011 9:20 pm

Assembly Answer

2011-04-03T21:00:48-05:00

Call ScrnSave(

You can't call ASM language by the name of the routine.
You have to use MASM to take that routine that's the *.ASM file, get it into hex values, then do something similar to what I did above, and run it, using

CALL ABSOLUTE()

~Kiyote!

I have a perfect example to illustrate this. Will grab & brb, and it WORKS too.

Statistics: Posted by Kiyotewolf — Sun Apr 03, 2011 9:00 pm

Assembly Answer

2011-04-03T20:57:56-05:00

This won't work, if you were to copy & paste into the QBasic IDE.

You have to either load values of assembly language into memory from DATA statements, or BLOAD a binary file with the ASM code into memory that way.

You can't insert ASM code written out like that for something like MASM to compile from.

MOV AX,[004F]
PUSH FF

That type of language above is INCOMPATIBLE WITH Qbasic.

00 F3 30 FE AB 99 02 04

A string of numbers like that, is ASM which CAN be put into QBasic, but you have to contain it first.

Code:

REM SAMPLE PROGRAMREM SHOW PURPOSES ONLY ~ DO NOT RUNREM Working on simpler & smaller ASM routine to show & tell instead.DATA &HB8, &H13, &H0, &HCD, &H10, &HB8, &H12, &H10, &HBB, &H0, &H0, &HB9, &H0, &H1, &HBA, &H2E, &H1, &HCDDATA &H10, &HFC, &HBE, &H2E, &H4, &H2B, &HFF, &HB8, &H0, &HA0, &H8E, &HC0, &HB9, &H80, &HC, &HF3, &HA5, &HB4DATA &H0, &HC3, &H16, &HB8, &H3, &H0, &HCD, &H10, &HCD, &H20, &H0, &H0, &H0, &H0, &H0, &H2A, &H0, &H2ADATA &H0, &H0, &H2A, &H2A, &H2A, &H0, &H0, &H2A, &H0, &H2A, &H2A, &H15, &H0, &H2A, &H2A, &H2A, &H15, &H15DATA -1' Basic Codefile created from  C:\EXAMPLE.COMfinished = 0DO  READ a  IF a = -1 THEN    finished = -1      ELSE    a$ = a$ + CHR$(a)  END IFLOOP UNTIL finishedSCREEN 0WIDTH 80, 25COLOR 7, 0CLSSCREEN 13CALL absolute(VARSEG(a$))WHILE INKEY$ = "": WENDCLSEND

Although it's not perfect, it's a shell of what it looks like to use ASM in Qbasic.
The practice is correct, the execution is not, meaning the ASM routine hangs.
I'm not best at rewriting ASM yet, so the example ASM was from an automatically generated *.COM file, which displays a 320x200x256 graphic from the command line.

I will DEBUG up a tiny little ASM program, that plots a few points using BIOS calls, and follow up to this asap.

~Kiyote!

Statistics: Posted by Kiyotewolf — Sun Apr 03, 2011 8:57 pm

Assembly Answer

2011-03-24T03:19:39-05:00

Here is what I found at Microsoft. How to save and restore a text mode screen I find it interesting, it uses assembly, and it makes a call to an assembly file.

Code:

   Defint A-Z   '$Dynamic   Dim Storage(1999)   FirstLine = 1   LastLine  = 5   Cls   For X = 1 To 15       Color X       Print String$(80, X + 64);   Next   Locate 20   Print "Press a key to save the screen";   While Inkey$ = "" : Wend   'Call Ptr86(Segment, Address, Varptr(Storage(0)))  ' For QB 3.00.   Segment=VARSEG(Storage(0)) ' For QB 4.00   Address=VARPTR(Storage(0)) ' For QB 4.00   Call ScrnSave(FirstLine, LastLine, Segment, Address)   Cls   Print "Press a key to restore the top";   While Inkey$ = "" : Wend   'Call Ptr86(Segment, Address, Varptr(Storage(0))) ' For QB 3.00.   Segment=VARSEG(Storage(0))  ' For QB 4.00   Address=VARPTR(Storage(0))  ' For QB 4.00   Call ScrnRest(FirstLine, LastLine, Segment, Address)The following is SCRNSAVE.ASM, an assembly language routine. SCRNSAVE.ASM saves a portion of the text screen in QuickBasic: Code        Segment Byte Public 'Code'            Assume  CS:Code            Public  ScrnSaveScrnSave    Proc    FarBegin:      Push  BP            ;save registers for Basic            ;* Push  DS  DELETE THIS LINE            Mov   BP,SP         ;locate stack to get variable                                ;addresses later            PUSH  DS            ;* SAVE THE DATA SEGMENT            PUSH  ES            ;* SAVE THE EXTRA SEGMENT            Mov   DX,0          ;look at low memory using ES            Mov   ES,DX            Mov   BX,0B000h     ;assume monochrome screen segment for                                ;now            Mov   AL,ES:[410h]  ;get the equipment list            And   AL,48         ;just look at the monitor type            Cmp   AL,48         ;is it monochrome?            JZ    Get_Params    ;if yes, skip over adding 800h            Add   BX,800h       ;if no, adjust for color-screen memory            Mov   AL,ES:[487h]  ;if an EGA is present, AL will not be                                ;zero            Cmp   AL,0          ;is it an EGA?            JNZ   Get_Params    ;if yes, leave DX set to zero as a                                ;flag for later            Mov   DX,3DAh       ;if no, specify the port to check for                                ;retraceGet_Params: Push  BX            ;save the screen segment for later            ;* Mov   SI,[BP+08] ;get the starting address of the                                ;storage array            ;* change to BP+6            Mov   SI,[BP+06]    ;get the starting address of the                                ;storage array            Mov   DI,[SI]       ;and put it into DI            ;* Mov   SI,[BP+10] ;get the segment for the array            ;* change to BP+8            Mov   SI,[BP+8]    ;get the segment for the array            Mov   ES,[SI]       ;and assign it to ES            ;* Mov   SI,[BP+12]    ;get the address for LastLine            ;* change to BP+10            Mov   SI,[BP+10]    ;get the address for LastLine            Mov   AL,[SI]    ;and put it into AL            Mov   CL,160     ;prepare to multiply times 160            Mul   CL         ;now AX holds the last screen address to                             ;save            Mov   BX,AX      ;save it in BX for later            ;* Mov   SI,[BP+14]    ;get the address for FirstLine            ;* change to BP+12            Mov   SI,[BP+12]  ;get the address for FirstLine            Mov   AL,[SI]     ;put it into AL            Dec   AL          ;adjust 1-25 to 0-24            Mul   CL          ;calculate actual starting address on                              ;screen            Mov   SI,AX       ;now SI points to the source address            Sub   BX,AX       ;calculate the number of bytes to copy            Mov   CX,BX       ;put it into CX for Rep or Loop below            Shr   CX,1        ;divide CX by 2 to obtain the number of                              ;words            Pop   DS          ;retrieve the screen segment saved                              ;earlier            Cld               ;all data moves below will be forward            Cmp   DL,0        ;are we doing monochrome or EGA?            JZ    Mono        ;if monochrome, skip over the retraceNo_Retrace: In    AL,DX       ;get the video-status byte            Test  AL,1        ;test just the horizontal retrace part            JNZ   No_Retrace  ;if doing a retrace, wait until it is                              ;notRetrace:    In    AL,DX       ;get the status byte again            Test  AL,1        ;are we currently doing a retrace?            JZ    Retrace     ;if no, wait until we are            Lodsw             ;now get the word from the screen            Stosw             ;and put it into the array            Loop  No_Retrace  ;loop until done            Jmp   Exit        ;skip over the monochrome routine and                              ;exitMono:       Rep   Movsw       ;move the data in one operationExit:       POP   ES          ;* ADD THIS LINE            Pop   DS          ;restore registers for Basic            Pop   BP            Ret   8           ;return skipping the passed parametersScrnSave    EndpCode        Ends            End   ;* REMOVE THE LABEL BeginThe following is SCRNREST.ASM, which restores a portion of the text screen in the QuickBasic program: Code        Segment Byte Public 'Code'            Assume  CS:Code            Public  ScrnRestScrnRest    Proc    FarBegin:      Push  BP            ;save registers for Basic            ;* Push  DS  DELETE THIS LINE            Mov   BP,SP       ;locate stack to get variable addresses                              ;later            PUSH  DS          ;* ADD THIS LINE            PUSH  ES          ;* ADD THIS LINE            Mov   DX,0        ;look at low memory using ES            Mov   ES,DX            Mov   BX,0B000h   ;assume monochrome screen segment for                              ;now            Mov   AL,ES:[410h];get the equipment list            And   AL,48       ;just look at the monitor type            Cmp   AL,48       ;is it monochrome?            JZ    Get_Params  ;if yes, skip over adding 800h            Add   BX,800h     ;if no, adjust for color-screen memory            Mov   AL,ES:[487h];if an EGA is present, AL will not be                              ;zero            Cmp   AL,0        ;is it an EGA?            JNZ   Get_Params  ;yes, leave DX set to zero as flag for                              ;later            Mov   DX,3DAh     ;no, specify the port to check for                              ;retraceGet_Params: Mov   ES,BX       ;set ES to the appropriate screen                              ;segment            ;* Mov   DI,[BP+12]    ;get the address for LastLine            ;* change to BP+10            Mov   DI,[BP+10]    ;get the address for LastLine            Mov   AL,[DI]      ;and put it into AL            Mov   CL,160       ;prepare to multiply times 160            Mul   CL           ;now AX holds last screen address to                               ;restore            Mov   BX,AX        ;save it in BX for later            ;* Mov   DI,[BP+14]    ;get the address for FirstLine            ;* change to BP+12            Mov   DI,[BP+12]  ;get the address for FirstLine            Mov   AL,[DI]     ;put it into AL            Dec   AL          ;adjust 1-25 to 0-24            Mul   CL          ;calculate actual starting address on                              ;screen            Mov   DI,AX       ;now DI points to the destination                              ;address            Sub   BX,AX       ;calculate the number of bytes to copy            Mov   CX,BX       ;put it into CX for Rep or Loop below            Shr   CX,1        ;divide CX by 2 to obtain the number of                              ;words            ;* Mov   SI,[BP+10]    ;get the segment of the storage                                    array            ;* change  BP + 8            Mov   SI,[BP+8]    ;get the segment of the storage array            Mov   AX,[SI]       ;and save it in AX for a moment            ;* Mov   SI,[BP+08] ;get the address of the first array                                ;element            ;* change to BP+6            Mov   SI,[BP+06]  ;get the address of the first array                              ;element            Mov   SI,[SI]     ;and put it into SI            Mov   DS,AX       ;okay to change DS after getting all                              ;variables            Cld               ;all data moves below will be forward            Cmp   DL,0        ;are we doing monochrome or EGA?            JZ    Mono        ;if monochrome, skip over the retraceNo_Retrace: In    AL,DX       ;get the video status byte            Test  AL,1        ;test just the horizontal retrace part            JNZ   No_Retrace  ;if doing a retrace, wait until it is                              ;notRetrace:    In    AL,DX       ;get the status byte again            Test  AL,1        ;are we currently doing a retrace?            JZ    Retrace     ;if no, wait until we are            Lodsw             ;now get the word from the screen            Stosw             ;and put it into the array            Loop  No_Retrace  ;loop until done            Jmp   Exit        ;skip over the monochrome routine and                              ;exitMono:       Rep   Movsw       ;move the data in one operationExit:       POP   ES          ;* ADD THIS LINE            Pop   DS          ;restore registers for Basic            Pop   BP            Ret   8           ;return skipping the passed parametersScrnRest    EndpCode        Ends            End   ;* REMOVE THE LABEL Begin

I hope this helps anyone ever wanting to use assembly in qbasic I know this is awesome for me; never knew how. [/code]

Statistics: Posted by TRANERAECK — Thu Mar 24, 2011 3:19 am