Department of Computing

Local Navigation

• Comp Home
• Unit Home

YAAS (Yet Another Assembly Simulator)

YAAS is a simulator for a simple assembly language.

• A brief users guide to Yaas.
• The language accepted by Yaas.
• Some sample files : decimal | addition | arithmetic | ifthen | loop | loop2 | power | max | precision

You can download executables for YAAS here only Win32 (95/98/NT/2000) executables are available.

Make sure that your computer is displaying the file extensions. On Windows 2000 in Explorer go to Tools -> Folder Options -> View -> and uncheck the box "Hide file extension for known file types".

• Dynamically Linked (64K - Right click and save target as yaas_d.exe) - Try this one first (it's a smaller download). If it won't run on your system, read on. This executable relies on certain DLL's being present on your system, and they usually are. (Another copy is here)
• Statically Linked (384K - Right click and save target as yaas_s.exe) This is a complete executable which needs no DLL's, and should run on any Win32 system. (Another copy is here)

If you cannot get YAAS to work on your home computer, you will have to complete the assignment in the labs.

Some problems that are known about:

• Sometimes when i reset YAAS i get large junk numbers in the memory. Can you fix this bug ?

  It's not a bug, its a feature :-) Seriously, you shouldn't rely on anything being in memory that you didn't put there (or get told someone else would put there). In particular, you shouldn't assume memory locations default to zero.

• Why do we have to use a text editor - can we edit the programs in YAAS ?

  This is also intentional. Being able to find and fix syntax errors is one of the skills you must develop in COMP125, and having YAAS edit would defeat this.

Outstanding bugs (which may get fixed one day):

• Yaas doesn't really support comments, but it does ignore stuff at the end of a line. However, if this stuff includes a : (colon), yaas gets very confused. If it's the first line, Yaas crashes.

  Workaround: Don't put :'s in comments, especially on the first line.

• Yaas has a maximum line limit. This has been increased to 200 lines in the web version, which should be more than sufficient for the assignment. This is lines of code in your program, not operations (which also has a limit, but much higher).
• It only runs on windows. (Fixed Oct 2002, YP)
• The `Go' button doesn't work correctly sometimes (dynamic on 95).
• The "automated tests" give an error "parse xxx, COMPILE FAILED" although the YAAS program works on Windows machines.

  Workaround: Remove empty lines from your program

Comments to: comp125-admin@ics.mq.edu.au