Magoo
For my money (and this may be the one you were referring to) is a 747-400 sim called PS1.
http://www.aerowinx.com
For the price I don't think you can beat it. I am not a pilot but I know several who used it to assist with conversion to glass cockpit/FMC etc. There is a new version planned for release in a few months that has enhanced features such as TCAS,company options for engine configs etc.
There is one planned for the 73 and 76 but I think that's a couple of years off.
The Void