The Virtual VS is a software emulator for the Sequential Circuits Prophet VS vector synthesizer. The software allows any PC to emulate the features and classic sound of the Prophet VS. Think of it as being a virtual rackmount Prophet VS that sits inside your PC.

The synthesizer generates CD quality sound (16-bits at 44100 Hz). The output is more or less faithful to the original Prophet VS. I am interested in hearing from anyone who has practical suggestions on improving sound quality.

The synthesizer accepts MIDI commands coming in over your MIDI port. It can also output commands over the port. When connected to a real Prophet VS, patches can be transferred to and from the Virtual VS.


June 12, 2004

Version 1.1 software is released. Get it in the attachments section below.


June 9, 2004

Site goes online. Version 1.0 software is released. Get it in the attachments section below.

Note: filter emulation is not that good yet, but gets the job done. If anyone can assist in improving the analog filter section, I'd be interested in hearing from you.



What is a ROM?

ROM stands for Read Only Memory. These are the chips inside a real Prophet VS used to store the firmware program. The software programmed into the chip controls the Prophet VS, much like a game 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?

Before you get started, I suggest you read up a little on the process. The following is a good site with information about ROM dumping.


First you need to get access to an EEPROM programmer. These tools can read from and write to ROM chips. 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.

Here are links to a couple of cheap, easy to use USB powered programmers suitable for hobbyists. I'm told they're both quite useful in the hobbyist space.

Second you need to carefully remove the ROM chips from your VS, put them into the reader, and dump their contents to a file on your PC. Don't forget to return your ROMs to your VS when done!

Third, 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.