#Emu8086 exercises code#
Modify your code so that:- Define: BUS_TITLE DB COMPUTER WIZARDS- WORK_SPACE DB 16 DUP(20H)- Move BUS_TITLE to WORK_SPACE from left to right (CLD)- MOV BUS_TITLE to WORK_SPACE from right to left (STD)- COMPARE BUS_TITLE with WORK_SPACE, print equal if equal, print not equal if not5. MAINPROC FAR MOV AX, DATASEG MOV DS, AX MOV ES, AX Please insert your code here MOV AX,4C00H exit procedure INT 21HMAIN ENDP ,132TITLEMovePracticeMove -STACKSEGMENT PARA STACK 'Stack'DW 32 DUP(0)STACKENDS -DATASEGSEGMENT PARA 'Data' Please insert your data declaration here DATASEGENDS Cut and paste (or type) the following code (as shown in the next page) and save move.asm Open your browser and open this page:C:\emu8086\documentation\8086_instruction_set.htmlAndC:\emu8086\documentation\8086_and_dos_interrupts.html2. MOV CX, 21LEA DI, RESULTLEA SI, PATTERNREP MOVSW Replicating a patternPATTERN DB |-|RESULT DB 42 DUP ( ) check_cx: if CX 0 then do following chain instruction CX = CX - 1 if ZF = 0 then: go back to check_cx else exit from REPNE cycle else exit from REPNE cycle REPNERepeat following CMPSB, CMPSW, SCASB, SCASW instructions while ZF = 0 (result is Not Equal), maximum CX times. MOV AL, rMOV CX, 8 LEA DI, STRING1REPNE SCASB
(Similar to indexOf in java or strstr in C) ES: - AL set flags according to result: OF, SF, ZF, AF, PF, CF if DF = 0 then DI = DI + 1 else DI = DI - 1 Continue to Compare bytes: AL from ES: while the comparison is not equal or until CX is 0 SCASB: SCAN STRING INSTRUCTIONScan a string for a specified value. check_cx: if CX 0 then do following chain instruction CX = CX - 1 if ZF = 1 then: go back to check_cx else exit from REPE cycle else exit from REPE cycle REPE (repeat if equal)Repeat following CMPSB, CMPSW, SCASB, SCASW instructions while ZF = 1 (result is Equal), maximum CX times. MOV CX, 8LEA DI, STRING2LEA SI, STRING1REPE CMPSBJNE exit DS: - ES: set flags according to result: OF, SF, ZF, AF, PF, CF if DF = 0 then SI = SI + 1 DI = DI + 1 else SI = SI - 1 DI = DI - 1ĮxampleSTRING1 DB COMPUTERSTRING2 DB COMPUTER
#Emu8086 exercises generator#
linear congruential random number generator by D.Processing String Data and Binary Data (continue)Ĭode for last practice exerciseDATASEGSEGMENT PARA 'Data' Please insert your data declaration here DES_STR DB 50 DUP ('$') ParaList label byte maxlen DB 50 actlen DB ? SRC_STR DB 50 DUP ('$') DATASEGENDSĬode for last practice exercise Code for reading input from keyboard MOV AH, 0AH LEA DX, ParaList INT 21H Code for reversing the string LEA SI, SRC_STR LEA DI, DES_STR MOV CH,0 MOV CL, ACTLEN DEC CX ADD DI, CX INC CX L10: LODSB MOV, AL DEC DI LOOP L10ĬMPSB, CMPSW Compare String InstructionCompare bytes: ES: from DS. (If there are problems, simply ask) int assembly86() unsigned short lehmer_sh(unsigned short s) I am sure you will be able to extend the assembly code for storing the rnz appearing in register dx in an array. I omitted this not-that-important step in assembly code. This is somewhat more practial when using it.
Between assembly and C functions there is a small difference: the return value of C function is furthermore mapped on interval. You can then watch the dx register where 10 rnz will be computed within loop RN.ĭeep down there is also my C function which I translated into 80x86 assembly. You can simply copy this code into EMUs editor (and put some entry and exit code around it). 65535) somewhat better.īelow 80x86 code is embbeded in Visual C++ program. Instead of 19683 you can also use 59049 (3*19683) what utilize 16bit (max. For you are restricted to 16 bit registers ax, bx etc.
#Emu8086 exercises mod#
Classical method for computing pseudo random numbers is the linear congruential random number generation method by Lehmer, where a new rnz is given by z(k+1) = (a*z(k) + b) mod m. EMU8086 does not have random number generator. If you are using EMU8086, I suppose you are about to learn assembly programming and generating a sequence of random numbers seems to be kind of exercise.
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