LC-3 Simulator Bugs

Get the latest simulator version: 1.0.5

Previous versions:
version 1.0.4
version 1.0.3
version 1.0.2
version 1.0.1

This document summarizes the known bugs in the LC-3 simulator. Please send detailed bug reports to cse240 at

Current Bugs

LC-3 status label does not update correctly to "halted" every time the machine halts, under Java 1.5 (noted by zarko).

The immediate offset for LDR instructions is missing its # sign (noted by zarko).

Resolved Bugs

Date Bug Noted by Fixed in version
11.12.05 The Keyboard Data Register is not cleared on a system reset. Atish Davda 1.0.5
11.04.05 The Display Status Register is never "ready" when running in GUI mode. Mark Fickett 1.0.4
10.31.05 Using the 'input' command silently disables the Text I/O console device, and the device cannot be re-enabled without closing and re-opening the simulator. zarko 1.0.3
10.30.05 The 'check' command doesn't work correctly when checking memory locations for negative decimal values. Chao Cai 1.0.3
10.24.05 Script commands after a 'continue' sometimes get queued without being processed; you have to enter another command to get them to execute. Chao Cai 1.0.2
10.13.05 Memory labels from previously loaded programs persist when a new program is loaded to the same address range. Mark Fickett 1.0.1


version 1.0.5
version 1.0.4
version 1.0.3
version 1.0.2
version 1.0.1

Last modified: Sat Nov 12 10:50:50 EDT 2005