README

*** 20 OCTOBER 2019 ***

I wrote this debugger/simulator back in 2007 as a way of alleviating boredom on
the cheap in a foreign country. I had many big plans for it which never
eventuated in the 12 years since I wrote it. As it stands, it allows you to run
small programs, single step, examine registers, and disassemble memory.

Yep, pretty basic stuff!

My primary reason for uploading this to GitHub is so it can be seen should
somebody be crazy enough to continue it.

***********************

This is the embryonic beginning of nd - a debugger/simulator,in the style of
Borland Turbo Debugger, for the Data General Nova minicomputer.

It is very much a work in progress. There is still a lot of work to be done,
not in the least being the simulation of more I/O devices and giving it a better
user interface using the ncurses library.

Why am I doing this?

Firstly, my C skills are pretty rudimentary so writing this is a way of
improving them. With problems, one encounters solutions and learns something
from them in the process.

Secondly, I have a pair of Nova 3 minicomputers and an Eclipse S/130 in
Australia which I couldn't take with me to Scotland. Surprised? Yes, I miss
them and being able to toggle trivial little program into the front panel
switches.

My initial aim is to provide an emulation of the basic hardware and some
necessary I/O. To be able to boot an operating system isn't high up on my list
at the moment. For something like that, go to

	http://simh.trailing-edge.com
	
and download simh. No really, do it!!!

That is not to discount the possibility of booting an OS in the future. Anything
can happen really. 'Tis a wide world I've opened the doors to, and with
increasing ability anything is possible. ;-)

Emil Sarlija - email: emil AT chookfest DOT net

CHANGES

02 JUN 2007 -	First executable & compilable version, only supports
Ver 0.01	"bootloader" paper tape format, no I/O

05 JUN 2007 -	Added a bunch of I/O instructions, CPU instructions, and TTO
Ver 0.02	simulation

05 JUN 2007 -	The simulator now dumps memory contents to screen as it loads
Ver 0.021	the program, plus bugfixes & cleanup - added by Toby Thain
		(Many thanks, great idea! - Emil)
		
06 JUN 2007 -	Added examine memory and disassemble commands. Also added
Ver 0.022	disassembly to the memory dumping while loading

07 JUN 2007 -	Fixed a bug in SKP<t> CPU. Added MUL/DIV and stack instructions.
Ver 0.03	Minor code clean-up as well. Really minor