Getting the ball rolling. Which VB6 projects are you working on?

[yereverluvinuncleber]

There are several ways to virtualise a Vax. The way we did it was to build the actual motherboards and other boards using software that allows you to build and emulate real circuits. You apply a 'real' voltage and the board does its stuff. A vast majority of semiconductors and logic circuits have already been created in this way so all of these cansimply be dropped onto a design. Then you need to build a real backplane and all the other elements of a 'real' Vax. When you have successfully built a Vax CPU (that's the tricky bit) then you can drop it onto a motherboard with all the other discrete components, connect them on the virtual backplane and the thing will just work. You can control the clock speed and other elements within the emulator. In this way VMS thinks it is really running on real hardware (as it is made of individual emulated devices, resistors, capacitors, logic chips) and new and specific boards can be built to run with the emulator as plugins.

Of course it runs on Windows as that is the industry standard for all corporate servers.
The reason for Windows is that one emulator instance can run on a typical 'blade' server and slot into a pre-existing rack and save the company 100s of thousands of £/$ in server room space alone taking up 1/50th (or even less) of the space of something like a typical Vax 6400. Windows fits into corporate enterprise strategies, so it is a no-brainer for managers to save potentially millions.

For each Vax/multi-core Alpha, it is one-to-one CPU relationship with one additional blade CPU dedicated to the emulator and another for Windows itself, two is best. Each drive is emulated as a container file and a SCSI card for the PC allows you to connect TK50s/TK70s or similar to exchange data. We had a stock of TKs.

Back to VB6! Good deviation though.

PS. Real/emulated Vax/Alphas run nuclear power stations, oil refineries, rail trackside systems, traffic lights, aeroplane design systems, Airbus is just one example. All important, all vital, none of it trusted on Windows but if it is a 'real' Vax that can be rebuilt in a matter of minutes/hours on a PC then the Vax on Windows tradeoff can be acceptable. There are security/performance risks however which are not apparent to a typical PC support engineer (ie. children).