LC-3 Simulator Bugs

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

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).

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

Fixed bug with 'check' command and negative decimal values.
The 'reset' command now re-enables the Text I/O Console in the GUI. Additionally, the Console changes colors to indicate whether it has focus or is disabled.
Added the 'dump' command for dumping memory ranges to a text file. See the LC-3 manual for information on this and other new features.
Added check pass/failure counting, via the 'check count' and 'check reset' commands.
The LC-3 timer device can now be controlled manually: a "." (period) read from an input file or from the Text I/O Console will generate a "tick." Set the timer interval to 1 to enable this manual behavior.

Fixed post-continue script commands bug.
'set' and 'check' commands now both accept memory ranges are arguments, so "set x3000 x300a 15" will set 11 addresses, starting at x3000, to have the value 15. "check x3000 x300a 15" will verify that those 11 addresses each indeed contain the value 15.
Prefixing a '@' character to a command prevents it from being added to the command history. This is done automatically for commands in script files, so they no longer "pollute" the history.

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