Skip to content

Document the committed program and its fixed operands in the README #10

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
dmccoystephenson merged 2 commits into from
Sep 4, 2026
Merged

Document the committed program and its fixed operands in the README #10

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
6892b5c
Document the committed program and its fixed operands in the README
dmccoystephenson Sep 2, 2026
5be87f4
Describe the loop by its source order rather than by unverified behavior
dmccoystephenson Sep 2, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 13 additions & 0 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,2 +1,15 @@
# multiplyTwoNumbers
A simple program in LC3 Assembly that multiplies the R1 and R2 registers and stores the result in R0.

## What is committed

`src/multiplyTwoNumbers.asm` is a single LC-3 program, originating at `x3000` and ending with `HALT`. It is made up of two blocks:

- `TESTCODE:` clears R1 and R2, then loads 5 into R1 and 6 into R2.
- `MULTIPLY:` clears R0, then adds R1 into R0, decrements R2, and branches back to `AGAIN` on a positive result — in that source order, with the branch written after the addition. Multiplication is performed by repeated addition.

Because `TESTCODE:` loads its two operands unconditionally, the operands are fixed at 5 and 6 in the file as committed. The header comment of the source describes a different, caller-supplied contract — `pre execution we have num1 in R1 and num2 in R2` — and that contract is not reachable while `TESTCODE:` runs first. Which of the two is intended has not been decided.

## Building and running

No LC-3 assembler or simulator is named by this repository, so no build or run command is documented here yet. The file is assembled with an LC-3 assembler and run to `HALT` in an LC-3 simulator; the result register is R0, per the header comment of the source.