To test the Larc Simulation....

The files in this directory are for testing the Logisim simulation 
of the Larc simulation.

Test1, test2, test3, and test4 were written for a previous semester.
Testall is new this semester -- if a simulation passes testall,
it is likely to pass the other tests as well.  It will be the
first test that is run on your simulation for grading.  However,
it might be better to start your own testing with test1 and test2.
Test3 and test4 will give your simulation some more substantial
and meaningless tasks.


To run testall:
Load testall.ROM into the instruction memory by right-clicking
the ROM and selecting "Load Image" from the popup menu.  Reset
the simulation, to make sure that PC is zero and the RAM is
empty.  Run the program until it halts.  You can then inspect
the contents of RAM by right-clicking the RAM and selecting
"Edit Contents" from the popup menu.  You can save the contents
of RAM into a file by right-clicking the RAM and selecting
"Save Image" from the popup menu.  Saving the RAM image should
produce a file that is identical to testall.RAM-AFTER-RUN.
Note that testall.s is the original Larc assembly program
that was used to create testall.ROM.

To run test1:
Load test1.ROM into the instruction memory [right-click the
ROM and select "Load Image"], reset the simulation, and let
the computer run until it halts. (Of course, you can also
step through the program by clicking the clock by hand.)
This  example tests all arithmetic operations and stores 
the results in memory.  Some of the memory store operations
use a non-zero SIMM.  test1.RAM-AFTER-RUN contains the contents
of data memory after running; if you save a RAM image after
running the test, the resulting file should be identical to
test1.RAM-AFTER-RUN.

To run test2:
Load test2.ROM into the instruction memory and run it. This
example counts down in hexadecimal f, e, ..., 1, and stores
the numbers in data memory.  The main point is to test 
a conditional branch instruction.  test2.RAM-AFTER-RUN contains
the contents of data memory after running.

To run test3:
Load test3.ROM into the instruction memory and run it.  This
example computes the 3N+1 sequence starting from 27 (0x1b), and
it stores the terms of the sequence into data memory starting
at location zero.  It takes a while to run.  The contents
of the data memory after the unmodified program was run are in 
the file test3.RAM-AFTER-RUN. (If you want a shorter run, 
you could change the first instruction to 8107 to compute
the sequence starting from 7 instead of from 27.)

To run test4:
Load test4.ROM into the instruction ROM AND ALSO load the
file test4.RAM-BEFORE-RUN into the data RAM. This test runs 
quicksort to sort the list of numbers in memory.  It took 
about 1/2 hour to run, using the default 8 KHz clock speed!
It still takes a while even using a faster speed.  After running, 
the numbers in locations 0 through 72 of the RAM will be sorted.  
This example tests the jalr instruction pretty throughly.
test4.RAM-AFTER-RUN contains a copy of the RAM content at the end.
The RAM will contain some numbers at the end from memory 
locations that were used as a stack for executing the recursive
quicksort procedure.  (For a shorter run, you could change the 
second instruction in the program to 8308.  Then, it will only 
sort the first 8 numbers in the list.)