What is a ROM?
ROM stands for Read Only Memory. It is the firmware program that is inside a real Prophet VS synthesizer. This software controls the Prophet VS, much like a cartridge controls a video game console.
Why do I need the Prophet VS ROMs?
The Virtual VS attempts to faithfully reproduce the hardware of the Prophet VS synthesizer. Being a hardware emulator, the Virtual VS uses the original software to control the features of the virtual synth. The original Prophet VS software is therefore needed to have a completely working emulator.
Because the software is separated, different revisions of the Prophet VS software can be loaded into the emulator. Your Virtual VS will behave according to whatever version of Prophet VS ROM that you have.
Where can I find the ROM images?
The software in the ROM images is owned by Sequential Circuits. Under current copyright law, any unauthorized distribution of the ROM image is illegal.
Do not ask me where you can find ROM images for the VS. All requests will be ignored.
I own an actual Prophet VS. How can I dump the ROMs?
First you need to get access to an EEPROM reader/writer. They aren't cheap, so if you have a friend into electronics, ask them if they can get you access to a reader for a few minutes. If that fails you can buy one, but they aren't cheap.
I use a BK Precision model 840 EEPROM Programmer to do the dumping of my ROMs. This model is out of production, but related models can be found at the following website:
The following is a good site with information about ROM dumping
There are lower cost (hobbyist type) readers available. Search around the net and you are bound to find many.
Second you need to carefully remove the ROM chips from your VS, put them into the reader, and dump their contents. Don't forget to return your ROMs to your VS when done!
Thirdly you need to combine the two 8-bit ROM files into a 16-bit interlaced MSB/LSB format. The following details how this interlacing should be performed:
The resulting interlaced data should be saved in a raw binary format. The resulting file should be exactly 64 kB in size.
Lastly, rename the ROM file to VS.bin and place it in the same directory as the emulator.