Soon after I started using MAME, I downloaded this strange file called 'Tempest Tubes'. It was a set of new and bizarre levels for Tempest, one of my all-time favourite games. I was intrigued - designing new levels for Tempest was something I had always wanted to do. I set out to find how it had been created, to no avail. The only solution was to write my own utility - and TempEd was the result.

After TempEd was released, Tempest Tubes' author, Duncan Brown, e-mailed me. I asked him how he had done it, and this was his reply (reproduced with his permission):

"It was 1982.  I owned an arcade at the time and we had a Tempest (of course!)  All of us Tempest geeks had gotten too good at the game, so we wanted to make it more challenging somehow. So, we bought another Tempest for the arcade (didn't want to mess up the people who weren't that good, so we had to leave a stock Tempest there too!) and I took it home one weekend and sat down with an Apple ][+ and a Mountain Hardware Promburner and a stack of 2716's and vowed not to sleep until I had it figured out!

"I had already spent a good deal of time reverse-engineering Asteroids, so I already knew the ropes of tearing apart Atari games (load the ROMs into the Apple memory and then use the built in monitor to disassemble it!)  But Tempest was much more daunting.  I knew it would take forever to reverse-engineer the code to the point I knew how to draw new tubes.  But I figured it just had to be data-table driven, rather than subroutines for each shape or whatever.  I figured if I could just find the table in ROM, it would be a simple cryptographic exercise from there.

"So, I took the brute-force approach.  With my Apple printout disassembly in hand it was fairly simple to spot the large areas of data (i.e. lots of illegal opcodes, etc.)  So again using the Apple monitor, I would go into each range of data and just stomp on a couple of dozen bytes in a row (setting them all to 01), burn an EPROM with that section in it, and plug it into the game. Obviously sometimes the game would crash, sometimes text messages would get whacked, and so on, but eventually I found what I was looking for - seriously whacked tubes from having done that to the data.  Then it was just a matter of repeatedly stomping on the data in significant ways until I figured out how the data was laid out and what each piece of data did.  YES, this took me the entire weekend!  I designed a whole bunch of tubes, settled on the 16 I liked best, and made a ROM.  I took the game back to the arcade and set it up with the new ROM and people loved it!  As you can tell, many of the shapes were designed to be significantly harder than the stock ones (the 3-lobed figure 8, the spiral death trap, the one that looks closed but isn't, etc.)  As you can also tell, I was 19 or 20 at the time (the "profile of a breast" tube!)

"Some of the other shapes I designed were pretty cool.  For instance, I did the entire set of letters in the word "Tempest" just like they were on the marquee.  Cool to look at, not so fun to play!

"I made copies for a couple of operator friends in the area, but it never went much farther.  Then, sometime in the mid 90's, I discovered rgvac, and I started stealthily distributing it to fellow collectors, but always disavowing any knowledge of it. The GameArchive guys posted a copy on their web site, which I guess made it even more widely known.  I was surprised when the Hasbro Interactive guys emailed me and asked if they could put it in their new arcade classics CD.  16 years after the fact, I was finally admitting it was I who did it..."

By contrast, creating TempEd was slightly easier thanks to MAME and Tempest Tubes itself. Duncan adds:

"If you think that was hard, I won't even tell you about stepping through all 6K of Asteroids code with a set of toggle switches and LEDs and a few legal pads to write the 1's and 0's on to...  (This was before I got the Promburner card and access to an Apple!!)"