I was able to track down Mark Dickenson, originator of the stereo SID mod and author of the StereoPlayer, who agreed to do an e-mail interview for CommVEx 2006.
Q: Would you tell us a little bit about yourself, Mark? What was your training as a programmer, for example? Did you have musical training? How about electrical engineering?
A: Where to start...
I started programming in 1977 when I joined the Air Force right out of high school. Back then, it was definitely old school using punch cards. I started programming in Fortran and COBOL. After leaving the Air Force I published a few games for the Radio Shack TRS-80. Learning to program on home computers back then was almost completely self taught.
While in high school I was in band for 4 years and that is where my music training came from. It definitely helped in creating the Stereo Sid Player.
My electrical engineering training was completely self taught and it definitely showed in the hand made stereo cartridges. I look back on those cartridges and get very embarrassed. I still have one of them along with one of the last Dr. Evil cartridges.
Q: How did you first get involved with the Commodore computers, and which versions did you use? What got you interested in SID music, and what software did you use early on?
A: I bought my first Commodore 64 in early 1986. I was actually working at a small Radio Shack at the time and they were selling Commodore 64's. They were not a company store but a franchise and could get away with it. So I ended up buying one. After that I bought one of the C-64 Portables. I used it more than the regular C-64. I even took it to the Sid Fests I attended. Then I purchased a C-128 and I still have that computer stored in a closet. I have always enjoyed music and at the time the music being created by the C-64 was astounding compared to other computers. I started delving into the internal hardware and software as soon as I bought my first C-64. I had the case open probably within 30 minutes of getting it home. I used a number of Tracker style music programs initially. Then I ran across Craig Chamberlains SidPlayer and really liked how you could use actual music notation. So I switched and started digging into how it worked.
Q: The Sidplayer by Craig Chamberlain and Harry Bratt was published in 1985, and the enhanced version in 1986. The Enhanced Sidplayer book describes a technique for using two computers to play stereo SIDs. How long was it before someone got the idea to add a second chip?
A: The idea came to me around January of 1987. I noticed the hardware addressing had open areas that were perfect for adding a second SID chip. So I started experimenting with different ways to add one and settled on piggybacking a second chip on the existing chip. I was surprised at how easily it came together and worked. Then came the hard part. Finding or creating something that could use it.
Q: Can you tell us a little bit about how the SID community on Q-Link contributed to the development of stereo SIDs? Who were some of the people involved?
A: After getting the second SID chip working I decided that the best way to get people to notice it would be to find a popular music application and create a program based on it that would use the second SID chip. So I started work on creating a Stereo Sid Player based upon Craig Chamberlains SidPlayer in February 1987. I was a member of Q-Link at the time I had frequented the SID Music chat rooms. I was one of those people who idled and never talked to anyone.
There were two people who had SID music that I really liked and listened to all of the time. They were Jerry Roth and Nick Zelinski. So I sent both of them a private message on Q-Link asking, "Would you like to make stereo sids?"
I could tell they thought I was some nut job little kid messing with them. I have to give some great credit to Jerry Roth for taking a huge leap of faith at the time. I sent him instructions on how to piggyback a second SID chip along with an early version of the Stereo Sid Player. Most people would never have risked the possibility of butchering their computer but Jerry went ahead and risked it and I am glad he did.
I was hoping he would like it and create 6-Voice music using SidPlayers Editor. It was a very cumbersome process at the time. I knew there was going to be a Sid Fest in June in Columbus Ohio and I wanted Jerry to create a 6-Voice stereo song for the occasion. He stepped up to the plate and delivered a fantastic composition of "Johnny B Goode".
We setup a table on the convention floor with a C-64 and stereo and just blew everyone away.
There were a large number of people who were incredibly helpful in the SID community. These people were some of the best I have ever had the pleasure to meet.
I know there are many people who should be on that list but after almost 19 years the memory fades. :) I miss those days and those wonderful people. I ran into some tough times around the early 1990's and lost touch with all of those wonderful people. I didn't find out that Jerry Roth had passed away until a year after he died. He played such a big roll in the Stereo Player and my life back then and it left a hole when I found out.
Every one of those people were great friends and I miss those times. :)
Q: In 1987 or 1988, you published instructions on how to "piggy-back" a second SID to get stereo sound (still available in issue 10 of C=Hacking magazine at http://www.ffd2.com/fridge/chacking/c=hacking10.txt). Would you tell us the origins of that technique?
A: Well, there really wasn't much to it. There was address space available and an unused pin for that address on the motherboard. Piggybacking a second sid chip on the existing SID chip was the easiest way to go about it. I don't know what else to say about it. :)
Q: Another design followed, in which the second SID was in an external cartridge rather than on the C64's circuit board. You even made some of these yourself. How did that design evolve, and what were some of the technical obstacles?
A: That was my attempt at trying to sell an external cartridge for people who didn't want to hack into their own computer with a soldering iron.
The boards were all hand etched and soldered from a hand drawn design. At the time I didn't have the startup money to have them professionally etched and it showed. I was definitely glad when Dr. Evil created their cartridges and I stopped making mine. I think I even shipped some Dr. Evil cartridges to people who bought mine instead.
Q: Did the appearance of the 64C with its new 8580 SID chip have any effect on the hardware and software people were developing?
A: Not really. About the only real change in the hardware were different filter capacitors for the new SID chip. Nothing really changed in the software.
Q: Around this time, Robert Stoerlle wrote an editor for creating stereo SIDs. Do you know any of the history behind that?
A: It was created out of necessity. It was a very time consuming process when it came to creating a 6-Voice SID. You would have to create two different music files using Craig Chamberlains SidPlayer Editor. Then change the extension of one file from .mus to .str. Then you needed to load Stereo Player to see how the music sounded combined. If you needed to make any changed you had to rename the .str file back to .mus and start the entire process all over again. It took a very long time to create a single 6-Voice song.
Robert Stoerlle created a fantastic 6-Voice editor that would allow you to edit and play the music within one application. This cut down development time considerably for 6-Voice music.
Q: Of course, once the stereo mod had been achieved, what was needed was a really good player that supported stereo, as well as the many features now available in SID files (words, pictures, etc.). What's the story behind the StereoPlayer? Did you add any features to the SID file format? What are .ANI files, for example? Can you tell us a little about the MIDI options in the menus?
A: There isn't too much of a story behind the Stereo Player. I wanted to create what could be the top program for playing SID .mus and stereo music files. I basically sat down and mapped out everything I wanted the program to do and gradually added each of the things I wanted as each version was released.
One of the changes I made was to how the existing .wrd files could be used. The default usage was scrolling a line up when a certain marker in the music was executed. I decided to expand upon that and offer a limited form of cell animation or text pictures with an Extended WRD format.
One of my grand ideas was the .ani file and I never completed it. The .ani file was going to give a kind of full screen animation using character graphics coupled with digitized sounds. I created a "Proof of Concept" .ani file with music and digitized sounds using "The Empire Strikes Back" theme. I never finished the .ani editor as it was a very involved project. Other things came up at that time and I just didn't have the time to finish it.
The MIDI option is the other idea that was never completed. You can make changes to the MIDI selections but they will not do anything. The Stereo Player needs a file called MIDI.MODULE installed in the same directory as the player. Some people received a test version but it was never released to the public. I, honestly, have no idea if I still have a copy.
Q: The StereoPlayer was wildly successful, and to this day is the program generally used for playing stereo SIDs. Were you surprised by its popularity? Were a lot of people asking for features?
A: I was hoping it would become very popular as it would open up a new world for the C-64 and it would make the C-64 one of the first home computers to have true stereo sound.
Honestly, I don't really remember if anyone asked for anything specific other than MIDI support. The Stereo Player basically has everything that I personally wanted to see in a SID Player.
Q: I'm sure everyone would be interested to know if you still have a Commodore 64. Do you still listen to stereo SID music?
A: I have a C-128 and it is stored in the closet and I haven't pulled it out in years. It is one of those I modified with the piggyback.
And I still listen to Stereo SID music from time to time. I have converted some of my favorites to stereo MP3s because it is easier to play them using something like WinAmp. I have Vice installed and a few music image files so I can play them using Stereo Player. For some reason they just seem to sound better when watching them play on Stereo Player. ;)
Q: Thank you for the interview, Mark. I'm sure everyone at CommVEx will enjoy hearing some of the stories behind one of the most popular and enduring pieces of Commodore software!
A: Your welcome and I hope everyone has a great time at CommVEx. :)