Twilight Zone Pinball: Romancing the Zone

Twilight Zone Pinball

Pinball Collector Becomes Pinball Developer

by Ted Estes

Editors Note: This article originally was featured in the late, great GameRoom Magazine. Ted Estes graciously allowed The GameRoom Blog permission to publish this great piece. Thanks Ted!

Note there is another article as part of this Twilight Zone series: Twilight Zone Pinball: Prototype vs. Production


I started playing video games at the same age as most people – my late teens. It was just the beginning of the video game boom, and I hardly paid attention to pinball, as I considered it an “old time game,” with lots of relays and steppers and such. That is, I felt that way until I headed to college and played my first game of Black Knight, and got hooked on modern pinball. I was so hooked that I scheduled time during the day to go to the arcade near campus. I played other new games of that era, but I spent most of my money on Black Knight. Eventually, however, I graduated, got a job, got a life, forgot about pinball – sound familiar?

Fast forward seven years to a conversation I had with a friend of mine from college. He mentioned in passing that someone he worked with had a Black Knight he wanted to sell. The idea of owning my own Black Knight was just too irresistible to pass up and the game was soon in residence in my basement. I was hooked again. The difference this time is that I was hooked to the extent that I now had to have a collection. So I bought another game, then another, and so on. I am certain that most readers of GameRoom Magazine can relate.

My pinball sickness story differs a bit from most, though, due to a very fortunate set of circumstances. In the summer of 1991, Jack Simonton, former editor of The Pinball Trader, traveled to Chicago on business and arranged a Williams Electronics Games plant tour with Larry DeMar. (Larry was a software developer back then; he is now director of Pinball Engineering for Williams.) Jack asked me if I would like to tag along, and I jumped at the chance, of course. I had attended the “Making of Funhouse” seminar at the Pinball Expo the year before, where Larry spoke about software development on that game, and I was anxious to meet Larry in person.

Looking to impress Larry, I brought along a little software project that I had been working on in my spare time. I had developed a pinball simulator that runs game ROMs from Williams pinballs on the PC, with the hopes of doing some program modifications to a few of my games. Larry was impressed by my little PC program and, being the shrewd judge of character that he is, commented, “You should be working with me.” I thought, “Yeah, right. I have a real job.” However, the idea stuck in my head, bounced around a bit, and I ended up interviewing for, then accepting, a software development position at Williams Electronics Games six months later. I was lucky enough to join Larry on Pat Lawlor’s design team, and worked on Twilight Zone as my first project. Three years after I attended the “Making of Funhouse” seminar, I was on the stage at the Pinball Expo myself as part of the “Making of Twilight Zone” seminar. Funny how things just work out sometimes.

Twilight Zone: a Recent Classic?

When I first started collecting pinball machines (and long before I was involved in the design of the games), the affordable games to buy were generally 5-7 years old. That meant tracking down and restoring a Black Knight or Centaur to add to one’s collection. Today, the 5-7 year-old games being added to home collections include Creature From The Black Lagoon, Indiana Jones, and, of course, Twilight Zone.

Modesty prevents me from gushing on about why Twilight Zone is such a terrific game to add to one’s home collection. On the other hand, I will not deny that it pleases me to see that Twilight Zone has become a favorite among the collectors. There are dozens of Internet Web sites dedicated to Twilight Zone ownership and maintenance. Questions appear weekly from new Twilight Zone owners on the Internet newsgroup At numerous pinball gatherings, I have had the pleasure of meeting many Twilight Zone owners who are anxious to offer some praise for the game or ask me some arcane question.

Since a change of job assignment from pinball to casino product development, I have been itching to do a little pinball programming. This, and the enthusiastic interest of the Twilight Zone fans, prompted me to get the silly idea of going back and fixing a few things in Twilight Zone‘s program. Also, I figured I might as well add a new feature or two, as long as I was taking the time to make a new software release. I was planning on doing a little programming and testing in the evenings at home, and get the project finished up in a few weeks. As it turns out, the project lasted – progressing in fits and spurts – for almost 16 months.

The Romance Begins

After psyching myself up to do a little home programming project, I needed to get a list of what people considered bugs in the current Twilight Zone software. I had a few ideas of things to add, but I also wanted to solicit ideas. I posted an article on asking for input, and got deluged with responses. Well, not really deluged, but I had a lot of suggestions. Some people went so far as to invent new major modes in game play and describe them in detail. Rules changes and additions were not in my plans, so I politely thanked the contributors and disregarded their suggestions. (I have to admit to giving consideration to a “3-way combo doubled by PowerBall rule, but sanity prevailed.)

I pared the “to do” list down to a few additions I wanted to make and fistful of bug reports. Eventually, I started working on duplicating and fixing the bugs, and then adding the new features. I made a test version of this new software and, with high hopes, asked some people to check it out for me. My spirits drooped when the bug reports started coming in. While I had done a good job of repairing the earlier bugs, my feature additions introduced a bunch of new bugs. I worked on fixing the newly found bugs and tidying up a few more loose ends, then made a second test version of software and sent it out about two months after the first one.

The second test version was better than the first, but it had problems, too. Another factor that I had not anticipated is that people were finding more pre-existing bugs, just because they were scrutinizing my new software that much more closely. So, not only was I busy fixing stuff that I had broken, I was now investigating stuff that had been in the game for a long time. As it turns out, real life intervened, and it took me quite some time to get around to looking into all the bug reports. The extra time also gave me a chance to think up another handful of features to add. The end result was that I spent a lot more time on this “little” project than I had anticipated. What started out being a fun diversion ended up being an awful lot like work!

So what are all the changes? Well, nothing earth-shattering, but I sneaked in a few interesting tidbits. I have outlined the changes below.

Bug Fixes

Keep in mind that the bugs fixed here are pretty obscure. Do not worry that your enjoyment of Twilight Zone will be hopelessly hampered by the presence of these bugs in an older software revision. These bugs have been catalogued after 5½ years and over 10,000 games made. I have kept the descriptions rather short, as the conditions under which these anomalies arise are very specific and detailed (and they do not make very interesting reading).

PowerBall/Multiball bug – When the PowerBall was the second ball served from the trough for multiball start, the game would not recognize that the PowerBall was in play.

Super Skill Shot bug – When a player completely missed the Super Skill Shot, and the ball hit no targets and drained, the next player up would get Super Skill Shot.

Bonus X Lamp bug – The Bonus X lamp was not shut off after Bonus X was earned; it continued to time out.

Multiball Start Ball Serve bug – In very rare cases, two balls would get served to the autofire kicker at the start of multiball.

Battle the Power lamp bug – In some cases after multiball with the PowerBall in play, the game would not be sure if the Powerball was in play. After it determined that the PowerBall was not in play, the Battle the Power lamp would not come on, even though the ball could be shot to the mini playfield.

Clock Chaos bug – If Clock Chaos was running at the same time as another mode was using the clock, hitting the Clock Millions target would speed up the clock.

Added Features

In adding stuff to Twilight Zone, I was guided by two main objectives: 1) Do not change the rules of the game; and 2) Do not get too ambitious. There are no “must have” additions here, but a few of them are pretty nice.

Lost in the Zone ball search – Half-way through the recycling of the balls at the end of Lost in the Zone, a ball search has been added when the balls cannot all be found.

Multiball End PowerBall Jackpot – There has always been a brief period of time after multiball ends where it is still possible to score a jackpot. It is now possible to score a PowerBall double jackpot.

New Lamp Effects – A few light shows were added, and a few existing ones were spruced up a bit.

Player-Selected Tournament Mode – Recent Williams pinball games allow the player to select the Tournament Mode of play before game starts. (Hold both flipper buttons before starting a game to see instructions on display.) This has been added to Twilight Zone.

Attract Mode speedup – One can now page through the attract mode display screens by hitting a flipper button.

Buy-In High Score to Date table – A separate High Score To Date table has been added for players who buy one or more extra balls.

Enhanced Custom Message – The custom message which can be programmed for display in attract mode now uses a nicer font.

Empty Balls test – Added a test menu entry for “Empty Balls.” This test will kick all balls out from anywhere they are held on the playfield. This is handy for removing the balls from the game in preparation for shipping.

Extra Special Edition
I could not resist making special software version for Twilight Zone, this version is intended for home use only. In the past, motivated Williams software developers have made home versions of software or “home ROMs,” but these versions have never been officially distributed by Williams Electronics Games. I decided to do a “semi-official” home ROM for Twilight Zone, since I had so many requests for it. The features I added to the home ROM are problematic for a game being operated for pay, so the Twilight Zone home ROM is “free play only.”

Lost in the Zone practice round – It is possible to “practice” Lost in the Zone by pressing and holding the Extra Ball button during game play. This lights the doorknob lamp, and the next shot to the Piano or Slot Machine will start Lost in the Zone. The player cannot enter initials for Lost in the Zone champion, and the score is cleared after the practice round. There is an adjustment “LITZ CHEAT OK” which will disable the practice round when set to “NO.”

Multiball Start 3-magnet special effect – Games with three spiral magnets installed (See accompanying article Twilight Zone: Prototype vs. Production.) will catch all three balls on the magnets at the start of multiball. This happens when there are zero or one balls in the lockup and the PowerBall is in the gumball machine.

Mute and Pause function – Have you ever been in the middle of a great game of pinball, only to have the phone ring? Well, Twilight Zone, now has a feature to allow you to pause your game. Catch the ball on a flipper then tap the Extra Ball button. The flipper will be held, and the game will go silent. To resume play, hold in the flipper button and tap the Extra Ball button again. (The game will resume automatically after 15 minutes.) This function can be disabled by a new adjustment, “MUTE & PAUSE OK.”

Final Thoughts

Even though my work on the Twilight Zone software update and home ROM was a rewarding experience, the chance of another software update of this magnitude happening is very remote. I was very lucky to actually have the time and facilities to do this work. When I was doing pinball software development at Williams Electronics, I had no urge to do even more of the same work when I got home at the end of the day.

I have been asked many times why Williams Electronics will not go back and fix some bug in an older game. It all boils down to a business decision. While Williams Electronics is dedicated supporting its products, and software updates are quickly provided for major fixes, expending effort on a game that is several years old steals precious resources from new game development. Also, I know most software developers feel the same way I do – that working on the next, new game is much more interesting than going back and reworking an old one.

Another question that frequently arises is the existence of home ROMs for various games. As I mentioned above, home ROMs exist solely due to the motivation of the software developer involved on a particular game. Given the busy work schedules of the developers, it is not surprising that home ROMs exist for so few games. Since home ROMs are usually not extensively tested and sometimes contain rather whimsical features, they are not intended for use in a pinball machine operated for money. As such, home ROMs are not officially supported by Williams Electronics, and the ROMs can not be set to “pay for play.” On the other hand, I am grateful that my employer is good enough to recognize that even though they are in the business to make money, we also sell fun and entertainment, and they give me and my coworkers the freedom to do a little side project for our (and our friends’) entertainment.

Ted Estes holds degrees in Electrical Engineering and Computer Engineering from Purdue University and University of Illinois. Before working at Williams Electronics Games, Inc., Ted spent several years working for AT&T Bell Labs. At Williams, Ted was a member of the software development teams for Twilight Zone, Demolition Man, and Roadshow pinballs, and helped out on numerous others.

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