(spim) read "s.out"
(spim) run
IfThen test: a=10
Nested IfThen-ELse: a=10
IfThen-ElseIf test: a=10
IfThen-Else test: a!=23
IfThen-ElseIf-Else test: a=10
(spim) help

SPIM is a MIPS R2000 simulator.
Its top-level commands are:
exit  -- Exit the simulator
quit  -- Exit the simulator
read "FILE" -- Read FILE of assembly code into memory
load "FILE" -- Same as read
run <ADDR> -- Start the program at optional ADDRESS
step <N> -- Step the program for N instructions
continue -- Continue program execution without stepping
print $N -- Print register N
print $fN -- Print floating point register N
print ADDR -- Print contents of memory at ADDRESS
print_symbols -- Print a list of all symbols
reinitialize -- Clear the memory and registers
breakpoint <ADDR> -- Set a breakpoint at address
delete <ADDR> -- Delete all breakpoints at address
list -- List all breakpoints
. -- Rest of line is assembly instruction to put in memory
<cr> -- Newline reexecutes previous command
? -- Print this message

Most commands can be abbreviated to their unique prefix
e.g., ex(it), re(ad), l(oad), ru(n), s(tep), p(rint)