[Simh] Unit/functional testing simulators

[Seth Morabito]

Hello all,

This last weekend I decided to take a stab at implementing my first
simulator using the SIMH framework. My eventual goal is an AT&T 3B2
400 simulator, though clearly this will take quite some time to get
working.

Programming is my day job, I've been doing it for years. Over the last
decade or so, I've become addicted to testing my software, and I've
fully embraced test-driven development -- I tend to write a test
before I write a line of code. SIMH is entirely without test suites,
so of course I've had to forge on ahead without that safety net. I've
started writing my CPU code without tests. Since the 3B2's WE32100 CPU
is a fairly complex beast, I feel extraordinarily uncomfortable about
this.

I'd feel a lot better if I could just programmatically set up a test
harness to call sim_instr() in a single step. It looks like there's a
lot of SCP setup that needs to be done before sim_instr() can be
called. I may have to wade in and just try to suss out exactly how to
do it myself, but before I go down that route I thought I would ask if
anyone else has testing strategies they've been working on?

I'd love to see testing come to SIMH. It's never too late!

-Seth