$00$ INP $//$ Input the first value

$01$ STA $01//$ Store the input at mailbox $01$

$02$ INP $//$ Input the second value

$03$ STA $02//$ Store it at mailbox $02$

$04$ INP $//$ Input the third value

$05$ STA $03//$ Store it at mailbox $03$

$06$ INP $//$ Input the fourth value

$07$ STA $04//$ Store it at mailbox $04$

$08$ INP $//$ Input the fifth value

$09$ STA $05//$ Store it at mailbox $05$

$10$ INP $//$ Input the sixth value

$11$ STA $06//$ Store it at mailbox $06$

$12$ INP $//$ Input the seventh value

$13$ STA $07//$ Store it at mailbox $07$

$14$ INP $//$ Input the eighth value

$15$ STA $08//$ Store it at mailbox $08$

$16$ INP $//$ Input the ninth value

$17$ STA $09//$ Store it at mailbox $09$

$18$ INP $//$ Input the tenth value

$19$ STA $10//$ Store it at mailbox $10$

$20$ LDA $10//$ Load the last input value $($to check for $999)$

$21$ BRZ $22//$ If input is zero, jump to exit check

$22$ SUB $999//$ Subtract $999$ to check if input equals $999$

$23$ BRZ $01//$ If result is zero, jump to start user program at location $01$

$24$ LDA $00//$ Load a value that is non$-$negative

$25$ BRP $00//$ Always branch back to location $00$

$86$ INP ; Input the first value from the user

$87$ STA $01$ ; Store the first input at mailbox $01$

$88$ INP ; Input the second value

$89$ STA $02$ ; Store it at mailbox $02$

$90$ INP ; Input the third value

$91$ STA $03$ ; Store it at mailbox $03$

$92$ INP ; Input the fourth value

$93$ STA $04$ ; Store it at mailbox $04$

$94$ INP ; Input the fifth value

$95$ STA $05$ ; Store it at mailbox $05$

$96$ INP ; Input the sixth value

$97$ STA $06$ ; Store it at mailbox $06$

$98$ INP ; Input the seventh value

$99$ STA $07$ ; Store it at mailbox $07$

$100$ INP ; Input the eighth value

$101$ STA $08$ ; Store it at mailbox $08$

$102$ INP ; Input the ninth value

$103$ STA $09$ ; Store it at mailbox $09$

$104$ INP ; Input the tenth value

$105$ STA $10$ ; Store it at mailbox $10$

$106$ LDA $10$ ; Load the last input value $($to check for $999)$

$107$ BRZ $108$ ; If input is zero $($after inputting $999),$ jump to check for exit

$108$ SUB $999$ ; Subtract $999$ to check if input equals $999$

$109$ BRZ $01$ ; If result is zero $($input was $999),$ jump to location $01($user program start$)$

$110$ LDA $00$ ; Load a value that is non$-$negative $($simulating positive value$)$

$111$ BRP $86$ ; If the value is positive, loop back to location $86$

The code above follows the following guidelines and run and if it does not than make it do so:

Suppose a small program is permanently stored in the last few mailbox locations. A BRANCH instruction at location $00,$ also permanent, will start this program. This program will accept input values and will store them at consecutive mailbox locations, starting with mailbox $01.$ You may assume that these values represent the instructions and data of a user's program to be executed. When a $999$ is received as input data, the program jumps to location $01$ where it will proceed to execute the values just entered. The small program described here is known as a program loader, or$,$ under certain circumstances as a bootstrap. This program takes advantage that instructions and data are indistinguishable $($Von Neumann architecture$).$ Thus, instructions could be treated as if they were data, if necessary. Mailbox Mnemonic Opcode Comment $86$ LDA $98598//$ initialize the STORE instruction at loc. $9287$ STO $92392//$ storing the contents of mailbox $98,$ that is $30188$ INP $901//$ input a value $89$ SUB $97297//$ subtract $99990$ BRZ $01701//$ done loading$--$jump to $01$ for execution $91$ ADD $97197//$ restore input value $92$ DAT $00//$ store value. This will contain $3$XX$,$ with XX indexed $93$ LDA $92592//$ load the STORE instruction in $9294$ ADD $99199//$ increment it $95$ STO $92392//$ and resave it $96$ BRA $88688//$ continue with the next input $97$ DAT $999999//$ value $999$ for testing $98$ DAT $301301//$ initial STORE $01$ instruction as a data value $99$ DAT $011//$ value $1$ for indexing II$.-$ What you need to do $1.$ Load the above program loader in the LMC to understand what the program is doing. The instructions should be loaded in your LMC at the mailboxes indicated above $($that is they must start at memory location $86)$ to work properly. Ensure that in mailbox $00$ you have the instruction to branch to mailbox $86($first instruction of the program loader$).$ Note: The program below is used to fill the LMC memory with $999$ and is an example of $$self$-$modifying code$($try it in the LMC simulator$).$ As a matter of fact, the program loader works using the same principle. Change this program as required to load the program loader instructions starting in memory location $86.$ start LDA line ADD one STA line LDA data line STA $10$ BRA start HLT data DAT $999$ one DAT $12.$ Run the program loader and input the instructions of the following user program: $//$ Input two numbers and output the higher INP STA FIRST INP STA SECOND SUB FIRST BRP HIGHER LDA FIRST BRA DONE HIGHER LDA SECOND DONE OUT HLT FIRST DAT SECOND DAT Hint: Replace the mnemonics with the opcodes to input the instructions of this user program as numbers. $3.$ Move the program loader so that it starts at mailbox $00$