So this is for a school project: I need to design a program (using a branch loop) that stores 1 in memory location 91, 2 in 92 etc... to 5 is stored in 95. I am not very knowledgable of LMC and would like some advice on it. I use peterhigginson.co.uk/LMC for my code (if that helps). The program cannot be as simple as store 1 in 91, it has to be done using a finite loop. I can easily ace this in any other coding console, just not LMC. Any help mucho appreciated.
Thanks!
It's not such an easy question. For code that writes to different addresses, you have to construct the correct STA instructions, using the encoding that STA xx is 3xx.
Here's one way of doing it:
L LDA COUNT
ADD INS
STA X
LDA COUNT
X HLT
LDA COUNT
ADD ONE
STA COUNT
LDA FIVE
SUB COUNT
BRP L
HLT
COUNT DAT 1
ONE DAT 1
FIVE DAT 5
INS STA 90
There's a counter (stored in COUNT) that goes from 1 to 5, and each time through the loop L, it's added to 390 (which is stored at INS) -- this constructs the instructions STA 91, STA 92, .., STA 95 on iterations 1, 2, 3, 4, 5. This instruction is written at X, and then executed with A having the value of COUNT. The rest is just incrementing COUNT, and stopping when it gets larger than 5.
Here's a live link, which you can see this code running on my own LMC emulator.
