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4 i.e. 7 6 5 4 3 2 1 0 C 4 LD HL,STORE 3 DEFM " ADD HL,HL 3 LD A,(ST1) 3 LD (ST3),A 2 the number 2 i.e. C 7 6 5 4 3 2 1 0 2 and Carry 2 STORE BIN 69H 2 INTRODUCTION 2 A after (HL) 2 1 0 1 1 0 1 1 1 x (183 dec.) 2 LD (LREG),HL 2 DJNZ LOOP3 2 DJNZ LOOP2 2 DJNZ LOOP1 2 ADD HL,DE 1 where x is any number and is unaffected bytne instruction. 1 ve number we can holdin a single register, using this notationis 0 1 transfer (HL) to (DE), increment HL and DE, decrement BC, set PV flag if BC=0 1 transfer (HL) to (DE), decrement HL, DE, and BC, set PV flag if BC=0 1 the port whose number is in C 1 the memory location (IY) 1 the memory location (IX) 1 the memory location (DE) 1 the memory location (BC) 1 the location (HL) 1 the contents of the Accumulator is eXclusively ORed with 1 the contents of 1 the computer is HALTed until an interrupt comes to awake it again 1 the carry flag is set, ie Set Carry Flag 1 the carry flag is inverted, ie Compliment Carry Flag 1 the alternative AF registers 1 the accumulator is ComPared with 1 the Stack Pointer 1 the Refresh register 1 the RETurn address is POPped from the stack 1 the L register 1 the Interrupt vector register 1 the IY register 1 the IX register 1 the HL register 1 the H register 1 the Flag register 1 the E register 1 the DE register 1 the D register 1 the C register 1 the BC, DE, HL registers are all EXchanged with the alternative set 1 the BC register 1 the B register 1 the Accumulator is logically ORed with 1 the Accumulator is logically ANDed with 1 the Accumulator is NEGated, ie made negative 1 the Accumulator 1 the AF registers 1 search from (HL) Incrementing BC bytes for data in Accumulator 1 search from (HL) Decrementing BC bytes for data in Accumulator 1 rotate the accumulator and carry Right 1 rotate the Accumulator and carry Left 1 rotate the Accumulator Right, shifting bit 0 into Carry 1 rotate the Accumulator Left shifting bit 7 into Carry 1 rotate Right Decimal contents of (HL) with least significant end of Accumulator 1 rotate Left Decimal contents of (HL) with least significant end of Accumulator 1 reSTart at address 1 push the return address to stack and CALL 1 port with the above number 1 perform relative jump to 1 perform jump to 1 output from (HL) to port (C) increment HL, decrement B 1 ouTput to port (C), from block from (HL) Decrementing HL for B bytes 1 ouTput from (HL) to port (C) block from (HL) Incrementing for B bytes 1 oUTput from (HL) to port (C) Decrement HL, decrement B 1 memory location 1 location (IY+offset) 1 location (IX+offset) 1 is loaded with 1 is Shifted Right Logically, 0 is shifted into bit 7 1 is Shifted Right Arithmetically, sign bit unchanged 1 is Shifted Left Arithmetically, 0 is shifted into bit 0 1 is Rotated Right, shifting bit 0 into Carry 1 is Rotated Left shifting bit 7 into Carry 1 is PUSHed onto the stack and the SP decremented by 2 1 is POPped from the stack and the SP incremented by 2 1 is INCremented by 1 1 is EXchanged with 1 is DECremented by 1 1 invert all bits in A register, ie ComPLiment 1 input data from 1 if the Zero flag is set, 1 if the Zero flag is not set, 1 if the Sign flag is set, ie Minus, 1 if the Sign flag is not set, ie Positive, 1 if the Parity flag is sEt, ie Parity is Even, 1 if the Parity flag is nOt set, ie Parity is Odd, 1 if the Carry flag is set, 1 if the Carry flag is not set, 1 iNput into (HL) from port (C) increment HL, decrement B 1 iNput into (HL) from port (C) Decrement HL, decrement B 1 iNput from port (C), into block from (HL) Incrementing HL for B bytes 1 iNput from port (C), into block from (HL) Decrementing HL for B bytes 1 has taken from it the carry and 1 has added to it the carry and 1 has added to it 1 enable Interrupts. NOT PERFORMED BY SIMULATOR. 1 disable Interrupts. NOT PERFORMED BY SIMULATOR. 1 decrement B, if zero continue, if Not Zero perform relative jump to 1 decimal Adjust Accumulator 1 compare (HL) with A, increment HL, decrement BC 1 compare (HL) with A, decrement HL, and BC 1 change Interrupt Mode to 1 block transfer (BC) bytes starting at (HL) to (DE) incrementing 1 block transfer (BC) bytes starting at (HL) to (DE) decrementing 1 becomes c 1 0 1 1 0 0 0 1 c= old Carry 1 becomes 1 1 1 1 0 0 0 1 0 (-15 dec.) 1 becomes 1 1 0 1 1 0 0 0 1 old bit 0=1 RR r, and RR (HL) instructions ( RotateRight ) is similar to RL except that theshift around the 9 bits is to the right. 1 becomes 1 0 1 1 0 0 0 1 c c= old Carry 1 becomes 1 0 1 1 0 0 0 1 1 old bit 7=1 1 becomes 0 1 0 1 1 0 1 1 1 (91 dec.) 1 becomes 0 0 1 1 0 0 0 1 0 (49 dec.) 1 becomes 0 1 1 0 0 0 1 0 0 (196 dec.) 1 and Carry are rotated Left 1 and Carry are Rotated Right 1 Three types, or modes, of maskableinterrupts are available. 1 The Accumulator has subtracted from it 1 The programmer can arrange that maskableinterrupts (MI) are ignored. Within theZ80 there is a flag, the interrupt enableflag, that can be set and cleared.Depending upon the state of this flag MIwill be accepted or ignored. 1 Space missing 1 RRD Rotate Right Decimal (/10) 1 RLD Rotate Left Decimal (*10) 1 RETurn from Non-maskable interrupt: NOT PERFORMED BY SIMULATOR 1 RETurn from Interrupt: NOT PERFORMED BY SIMULATOR 1 RES N,(HL) 1 Offset too big 1 Offset missing 1 Number too large 1 Number missing 1 No OPeration is performed, inspite of this it takes . 1 No DEFB, or DEFW 1 NOT DEFINED 1 Missing space or , 1 Label too long 1 Label not found 1 Instruction unknown 1 FLAGS$ Registers and Contents % STAC 1 Error after inst. 1 EX5B:DEFM " LD HL,(STORE) 1 DEFM "using addition to successively multiply by" 1 DEFM "number held in the HL register pair by 10" 1 DEFM "instruction therefore divide 1 DEFM "becomes 0 1 0 1 1 0 1 1 1 (91 dec.) 1 DEFM " into bit 7. 1 DEFM " i.e. 7 6 5 4 3 2 1 0 C 1 DEFM " The SRL or Shift Right Logically" 1 DEFM " LD DE,(STORE) 1 DEFM " LD (STORE),HL 1 DEFM " ADD HL,DE 1 Cursor keys, delete, and auto-repeat are as standard. BREAK returns you to menu. 1 Can only ADD IX/IY 1 Bracket missing 1 BIT N,(HL) 1 All these instructions affect not onlythe Carry flag, but the Zero, Sign, andParity flags. 1 ADDRESS MACHINE CODE 1 1 or 127 and the largestnegative number 1 1 01 seconds to do it 1 0 or -128. 1 (viii)Return from interrupt (RETI). 1 (vii) Enables interrupts 1 (vi) POP or EXchange registers. 1 (v) Disable interrupt if required. 1 (iv) Do interrupt routine. 1 (ii ) PUSH or EXchange required registered(iii) Enables interrupt if required. 1 (i) Enter maskable interrupt, interrupts 1 '^+^2^9^=^D^K^R^b^i^y^ 1 x 1 0 1 1 0 0 0 1 1 x 0 1 1 0 0 0 1 0 (98 dec.) 1 where N is the bit number 0-7SET N,(HL) 1 to thisfield. 1 themultiplication and division of BCD numbersby ten. 1 single byte instruction, further 1 since number of "1"s is 1 rotate r and carry left 1 rotate r and Carry right 1 rotate A right, carry duplicates 1 rotate A left, carry duplicates 1 rotate A and carry left 1 rotate A and Carry right 1 operation. 1 of the Accumulator. 1 number of "1"s is 4 1 interrupts are accepted. 1 illustrate 1 i.e. even. 1 i.e. -2 is equivalent to 254 etc. 1 i.e. C 7 6 5 4 3 2 1 0 1 ectively multiplies a" 1 contents of the Accumulator by 1 complementing and adding 1 in one 1 c 1 0 1 1 0 0 0 1 1 are disabled at this time. 1 after RRD 1 after RLD 1 Z Zero 1 You are trying to run code in allocated storage area. RET missing? Please EDIT 1 You are about to write to memory which will affect your program. Please edit it. 1 You are about to affect memory area not allocated to you. Please edit program. 1 You should now be able to use otherassemblers to write your own programs.You will find that most are not souser friendly, and that you will notbe able to one step easily throughinstructions. Don't despair. You canalways return to this Tutor to simulateyour problem. 1 When performing arithmetic operationswhich we wish to interpret within therange -128 to +127, the Carry flag nolonger signals an out of range result.However another flag, the overflow (P/V)flag does. It is a "1" whenever the answeris outside the range -128 to +127 and "0"within the range. It is effectively acarry into bit 7 which would make the signbit incorrect. 1 When data is transmitted from one placeto another, it is possible for errors toappear in the received data. Parity is asimple way of detecting single errors indata. An additional bit is added to thedata that makes the total number of "1"sin the word an even number. If thereceived word does not have an even numberof "1"s in it, then an error has occurred. In addition to this even parity we coulduse odd parity, where the word is made tohave an odd number of "1"s in it. 1 We must return from an interrupt routinewith the instruction RETI ( RETurn from Interrupt ) and not RET. 1 We have so far treated information in theform of bytes or words. The Z80 does allowa number of operations on separate orgroups of bits within one byte 1 We have discussed flags as individualbits. This is the way they are normallyused. They are however actually stored inthe Z80 in a register, designated as F orflag register. The flags are arranged asfollows :- 1 To ensure that no other interrupt occursduring this period and therefore corruptsthe register contents before they aresafe, the interrupts are disabled duringthese operations. 1 This group of lessons will introduce thethe idea of bit manipulation and its usein flag operations and in producing fastermethods of multiplication. 1 This example uses shifts and rotateinstructions to multiply two 8 bitnumbers together. One number is rotatedto examine each bit in turn. The othernumber is also shifted and added to thetotal if the bit is set. This method isfar quicker than the method of repeatedaddition. 1 This example is a simple program toillustrate JP P,nn , and JP M,nn; jumpif positive and jump if minus. Note thatthe carry is still operative, andtherefore, if you do not clear it beforeADC and SBC the later jump could beunexpected. In this example the carry isnot cleared, so "look before you leap". 1 This completes a study of all theinstructions available on the Z80 chip. 1 These instructions are shift instructionsin which the bit that falls out one end ofthe register or memory location is pushedback into the other end. The Carry flageither forms part of the number shiftedthereby making it 9 bits long orduplicates the state of the bit that fellout of the register. There are thereforefour different types of rotate. 1 These examples illustrate the operationof rotate instructions. Modify the initialcondition of the location STORE toinvestigate their operation further. 1 There is no reason for sticking to 8 bitsusing this method. So long as the numberof bits is sufficient and the mostsignificant bit is taken as the sign bitany size positive or negative number canbe represented. 1 There are too many registers called up, to display. Program will RUN as normal. 1 There are 4 other rotate instructionsthat involve the Accumulator only. Theyare RLCA, RLA, RRCA, and RRA. They areidentical to RLC A, RL A, RRC A, and RR A,but only affect the Carry flag, and aretwice as fast. 1 There are three logical instructionsavailable on the Z80. They are allperformed on a bit by bit basis betweenthe Accumulator and a number, register, orindirectly addressed memory location (HL).The result is left in the Accumulator. 1 The two instructions that manipulate thisflag are 1 The stack pointer is outside allocated memory area. Please edit program. 1 The sign and parity flags can be used inall absolute ( NOT relative) jumps, calls,and returns. 1 The program has been completed. You may EDIT or reRUN. Exit by pressing BREAK. 1 The notation is :- 1 The last lessons deal with instructionsthat allow the outside world to interruptthe processor. 1 The final set of lessons introduces morespecialised registers and instructions,and looks at the way the Z80 can talk withthe outside world. 1 The examples illustrate the operation ofthe logic instructions. The pupil shouldtest his/her understanding further bymodifying the contents of the 3 stores. 1 The example shows the use of the Refreshregister as a source of random numbers. 1 The best way to describe these operationsis by example. Both instructions involvethe Accumulator, and the memory location(HL). The examples are in Binary CodedDecimal of course, each digit taking upone nibble or 4 bits of the register ormemory location. 1 The RRD instruction therefore divides thedecimal number by 10. It can also bestrung together to divide any length BCDnumber by 10. The low digit of the twodigit decimal number can be isolated bythis instruction. 1 The F register sometimes forms a registerpair in conjunction with the Accumulator.This pair is called AF. The onlyinstructions previously mentioned thatinvolve this register pair are PUSH andPOP. 1 The 3 shift instructions are illustratedusing a fixed initial value in the memorylocation STORE. 1 The three logical instructions AND, OR,and XOR affect the Zero, Sign, and Parityflags. The Carry flag is reset to "0" inall cases. Thus the limitation of no ClearCarry instruction can be perfomed simplyby a logical instruction. 1 The instruction performed determines themeaning of the P/V flag. 1 The following illustrates the way inwhich SET, RES, and BIT can be used tomanipulate individual bits of a registeror memory location. 1 The Z80 has two instructions that may beused for these operations 1 The Z80 has a flag that is set if thenumber of "1"s in a number is even. Thisflag is in fact the same flag as theoverflow flag. It is termed the P/V flag. 1 The Z80 allows us to rotate left andright nibbles as well as bits. 1 The Sign and overflow flags are alsooperative after ADC and SBC instruction onthe HL register. It reflects the 15th bit(or bit 7 of H register) . 1 The SRL r, and SRL (HL) instructionsshift the register/memory locationcontents right, shifting bit 0 into theCarry flag and a "0" into bit 7. 1 The SRA r, and SRA (HL) instructionsshift the register/memory location (HL)right, shifting bit 0 into the Carry flagand retaining the state of bit 7. 1 The SLA r, and SLA (HL) instructionsshift the register/memory contents leftshifting a "0" into bit 0 and bit 7 intothe Carry flag. 1 The interruptautomatically performs an RST or CALL toaddress 0066H on completion of the currentinstructions. The routine at 0066H isperformed. The instruction RETN or RETurnfrom Non-maskable interrupt returnscontrol back to the interrupted routine atits next instruction . 1 The SRL or Shift Right Logicallyinstruction therefore divides a positivenumber by 2. As with SRA the Carry flagindicates the half. 1 Summary - shift instructions 1 Summary - rotate instructions 1 Summary - logical instructions 1 Summary - decimal shifts 1 Summary - bit manipulation 1 STORE DEFW 254H 1 STORE BIN 16 1 ST3 BIN 0H 1 ST2 BIN FH 1 ST1 BIN 65H 1 SRL r divides +ve numbers 0 - 255 by 2 1 SRA r divides +ve and -ve numbers by 2 1 SOURCE CODE 1 SLA r multiplies +ve and -ve numbers 1 SHIFT INSTRUCTIONS 1 S and P/V FLAGS IN INSTRUCTIONS 1 S Sign 1 Return to operating system 1 RRD Rotates the Decimal number Right 1 RRC r, RRC (HL) instructions (RotateRight Carry being duplicated ) is similarto the RLC instruction but is a rightshift. Bit 0 is shifted into bit 7 and theCarry duplicates the old bit 0. 1 RRC r rotate r right, carry duplicates RRC (HL) 1 RR instructions can be strung together todivide any length number by 2. 1 ROTATE INSTRUCTIONS 1 RLD Rotates the Decimal number Left 1 RLC r, and RLC (HL) ( namely Rotate LeftCarry duplicating ), shifts the contentsleft, bit 7 rotating into bit 0, and theCarry duplicating the transferred bit. 1 RLC r rotate r left, carry duplicates RLC (HL) 1 RLC and RRC instructions are useful insequentially interrogating the wholecontents of a register without corruptingits contents. 1 RL r, and RL (HL) Rotate Left, rotatesthe register/memory location with theCarry as a 9th bit, left. 1 RL instructions can be strung together tomultiply any length number by 2, since theCarry is transferred between repeated RLinstructions. 1 Program stopped. You may re-RUN, EDIT or press BREAK to return to menu. 1 Program has successfully assembled. Press RUN, EDIT, or exit by pressing BREAK. 1 Program counter has jumped to non-valid address. EDIT or reRUN program. 1 Press SPACE to select and ENTER to start 1 Press SPACE to continue. 1 Press RUN to begin example, EDIT to edit, and BREAK to return to menu. 1 Please confirm disk loading required Y/N 1 Performing a similar calculation to theabove we can show that a register pair canrepresent a number in the range +32767 to-32768. 1 P/V Parity and overflow 1 One Non-Maskable Interrupt is availableon the Z80 chip. 1 Of all the instructions described to dateonly DAA treats it as a parity flag. Allothers either have no effect on it or useit as an overflow flag. All subsequentinstructions either have no effect on itor use it as parity. 1 NUM2 DEFB 203 1 NUM1 DEFB 212 1 NEG negates, or makes negative, the 1 N Subtract last 1 MODE 2 is the most flexible, the addressto which the processor is forced is theindirect address held in a memorylocation. The address of this memorylocation is computed from the contentof the I register, which provides thehigh byte and the interrupting devicewhich provides the low byte. Sincethe interrupt routine is addressedindirectly the interrupts are termedvectored interrupts. 1 MODE 1 is the one used by the Sinclairsystem ROM. It is set by the instructionIM 1. This mode is similar in operation tothe Non Maskable Interrupt except thatprocessor is restarted at 0038H insteadof 0066H as in the NMI. 1 MODE 0 is set by the instruction IM 0.This mode is the one described previously,where the RST n instruction is forced ontothe data highway to fool the processorinto performing the restart. 1 Loading lessons 26-35 1 Loading lessons 18-25 1 Loading lessons 10-17 1 Loading lessons 1-9 1 Loading has been stopped 1 Loading error 1 Load further lessons from disk 1 Load earlier lessons for revision 1 LREG BIN 0 1 LOOP4 RR (HL) 1 LOOP3 SRL (HL) 1 LOOP3 RRC (HL) 1 LOOP2 SLA (HL) 1 LOOP2 RL (HL) 1 LOOP2 ADC HL,BC 1 LOOP1 SRA (HL) 1 LOOP1 SBC HL,DE 1 LOOP1 RLC (HL) 1 LOOP RR A 1 LOOP LD A,R 1 LOOP INC (HL) 1 LOGICAL INSTRUCTIONS 1 LESSONS 26 - 35 1 LESSONS 18 - 25 1 LD HL,ST2 1 JP1 RET Z 1 JP PO,nn CALL PO,nn RET PO Parity odd 1 JP PE,nn CALL PE,nn RET PE Parity even 1 JP P,nn CALL P,nn RET P Sign +ve 1 JP M,nn CALL M,nn RET M Sign -ve 1 It is important to remember that the ZeroCarry, Sign, and overflow flags are alwaysoperative after an 8 bit arithmeticinstruction or a 16 bit addition involvingthe Carry. Your interpretation of theresult determines which flag(s) you shouldbe interested in. 1 Interrupts fall into two types, Non-Maskable Interrupts (NMI) and MaskableInterrupts (MI). Maskable interrupt can beignored by the software, but NMIs cannot. 1 In the XOR ( eXclusive OR ) instruction,if the bit in the Accumulator is the sameas that in the number , then thecorresponding bit in the result will be"0". If they are different it will be "1".Another way of looking at the XORinstruction is if one OR the other is "1"but NOT both, the answer will be "1". 1 In the OR instruction, if a bit in theAccumulator OR in the other number is a"1", the corresponding bit in the resultwill be "1". If not it will be "0" 1 In the AND instruction, if a bit in theAccumulator AND other number are "1",then the corresponding bit in the resultwill be "1". If not it will be "0" 1 If the condition is not met the programwill not jump, call a subroutine orreturn. 1 INTERRUPTS 1 Hence the result of the instruction SLAor Shift Left Arithmetically is tomultiply the positive number by 2. TheCarry indicates a result greater than 255. 1 Hence interrupt routine take the form:- 1 Hence the SRA or Shift RightArithmetically instruction divides bothpositive and negative numbers by 2. 1 HREG BIN 0 1 H Half carry 1 Ex - using alternative set 1 Ex - use of index registers 1 Ex - sign and parity flags 1 Ex - shift instructions 1 Ex - rotate instructions 2 1 Ex - rotate instructions 1 1 Ex - logical instructions 1 Ex - decimal rotation 1 Ex - control instructions 1 Ex - block transfer 1 Ex - block search 1 Ex - block I/O 1 Ex - bit manipulation 1 Ex - I/O instructions 1 Entry into a maskable interruptautomatically disables interrupt. 1 EXAMPLES OF SHIFT INSTRUCTIONS 1 EXAMPLES OF ROTATE INSTRUCTIONS 1 EXAMPLES OF LOGICAL INSTRUCTIONS 1 EXAMPLES OF DECIMAL ROTATION 1 EXAMPLES OF BIT MANIPULATION 1 EXAMPLES OF +VE AND -VE NOTATION 1 EXAMPLE USING ROTATE AND SHIFT 1 EXAMPLE OF JUMP ON SIGN 1 EI Enable Interrupts. After one more 1 Disk V1.0 (c) HanSoft '85 1 DI Disable Interrupts immediately. 1 DECIMAL ROTATE 1 CPL complements or inverts the contents 1 C Carry 1 But first we shall look further at theprocessors flags. 1 BIT MANIPULATION 1 As well as performing OR operations onour own flags, this instruction is usefulin SETting a group of bits in theAccumulator. 1 As can be seen the effect of stringingtogether RLD instructions is to multiply adecimal number by 10. It is also useful inisolating the high digit from the twodigit number. 1 As well as performing ANDs on our ownflags, this instruction is useful inmasking off areas of words, or resettinggroups of bits in the Accumulator. 1 Apart from performing the logical XORfunction on our own flags the XORinstruction is useful in invertingindividual or groups of bits. 1 Any bit in a register, or memorylocation using (HL), can be SET to a "1".We can also RESet any bit to a "0". Totest the state of a bit in a register, ormemory location, we can use theinstruction BIT. In this instruction theZero flag is set if the appropriate bitis "0" and reset to a "0" if theappropriate bit is "1". Hence we canproduce our own flags to indicate eventsand then act upon them later in ourprograms. 1 An interrupt originates from outside theprocessor, requesting it to break off itscurrent sequence of operations and dealwith some other function. 1 An interrupt can occur at any time.It follows therefore that if theinterrupted program is to be continued(i.e. be re entered), the contents of anyregister that the interrupt routine uses,must be stored or pushed onto the stack,and reloaded or POPped from the stackbefore returning 1 Although these examples appear to be allpositive, they can be viewed equally asnegative where appropriate and the Signand overflow flags observed operating.Remember a number above 128 is a negativenumber. Since all the negative numbers inthe examples are small, they can be seenquickly and simply be converted bysubtracting the number from 256. 1 All the above rotate instructions RLC,RL, RRC, and RR not only affect the Carryflag but also the Zero, Sign and Parityflags, as have all shift instructionsdiscussed. 1 AND A or OR A will clear the carry flagand not affect any registers. XOR A willclear Carry and the Accumulator. 1 A Sign flag (S) is provided on the Z80.It duplicates the sign ( bit 7 ) of theanswer after any arithmetic operation onthe Accumulator. The sign flag is "0" fora positive result and "1" for a negativeresult. 1 A shift instruction is one in which thebits of a register or memory location aremoved sideways, left or right to theadjacent bit. As we shall see, this givesus a means of division as well asmultiplication. 1 35. Finale 1 34. Interrupts 1 33. Processor control instructions 1 32. Block I/O instructions 1 31. Block search instructions 1 30. Block tranfer instructions 1 3 i.e. odd. 1 29. Block instructions - introduction 1 28. Input/Output instructions 1 27. The alternative set of registers 1 26. The index registers 1 25. Decimal rotating 1 24. Rotate instructions 1 23. Shift instructions 1 22. Logical instructions 1 21. Bit manipulation 1 20. S and P/V flags in instructions 1 19. The flag register and AF 1 18. Parity 1 1 1 1 0 0 0 1 0 x (-30 dec.) 1 1 0 1 1 0 0 0 1 x 1 1 0 1 1 0 0 0 1 c 1 01010110 ORed together 1 01010110 ANDed together 1 01010110 XORed together 1 0 1 1 0 0 0 1 0 x (98 dec.) 1 0 1 0 0 0 1 1 1 parity flag is set since 1 0 0 1 1 0 1 0 0 parity flag is not set 1 & clears all ENTER tabs to next line STOP assembles SPACE tabs in label are 1 XOR (HL) 1 THE FLAG REGISTER AND AF REGISTER PAIR 1 SET 6,(HL) 1 RES 3,(HL) 1 Loading error 1 LD DE,FFFEH 1 LD DE,33 1 LD DE,(NUM2) 1 LD A,(NUM1) 1 LD (HL),A5H 1 JR Z,LOOP 1 JR NC,JP1 1 JR LOOP1 1 JP P,LOOP1 1 JP M,LOOP2 1 Error found during assembly. Please correct before running program. 1 DJNZ LOOP4 1 BIT 2,(HL) 1 AND (HL) 1 GOOD LUCK and HAPPY PROGRAMMING 1 ASSEMBLED CODE LABELS INSTRUCTIONS 1 Enter the Z-80 simulator ? Y/N