COIN MECHANISMS                CONTROL         SOUND/ VIDEO AND COMPUTERS  

Adding sound, video and computers
The simplest and cheapest way to add sound and video to a slot machine or simulator used to be modified domestic CD and DVD players. I simply soldered wires to the contacts of the play and next track buttons to jump between tracks - and switch the power off at the end of each cycle to reset everything. Some hard disk and flash card 'media players' are now really cheap and are a good alternative.

Sound

Boom boxes (CD player, amp and speakers) cost about £20. There is a delay of about 6 seconds between power on and it playing, but it is possible to record the first track blank so the machine just has to skip to the next track when a coin is inserted. You obviously need some sound software on your computer, and a CD burner to master your CD.

Another possibility is to run MP3 files on a DV 68 video player (for details see under video). This manages to keep up to 100 tracks playing at the right moment, even when they are rapidly and randomly changing, which I find very impressive. Much cheaper is the V2 music module, sold by FTDI, with an Arduino controller. I used this on Whack a Banker and it works really well (about £15 for the Arduino and £22 for the V2music module) but it needs a bit more programming and electronics skill.  

For amplifying the MP3 sound, 'active' computer speakers are good value. These plug into the phono audio out sockets of a DVD or media player. A bass speaker and amp with two satellite speakers cost about £20. It doesn’t matter where the bass speaker is but the tweeters need to as close to the ears of the people using the machine as possible. This enables the sound to be easily audible without being played at high volume – which pollutes the rest of the space (conventional amusement arcades never seem to have applied this simple lesson).

Video

Video keeps getting cheaper and easier to incorporate. Until a few years ago, I ran the video animation for my simulator rides from set top DVD players. Starting the DVD playing at the same time as the main controller, they keep perfectly in sync as their internal timing circuits are both quartz controlled.

My first simulators ran using the Video CD format. The quality is amazingly good for a frame size of 320x480. Video material has to be converted to MPEG1 format (I used a program called Tempgnc). Then in the menu of your CD burning software you should find an option for video CD, which you can add MPEG1 files into. Set top DVD players automatically start playing track one of a video CD, and will skip to the next track when the next button is pressed.

DVD format is 720x576 pixels so the picture does look sharper. To make a suitable DVD – without a preset ‘menu’ page - needs authoring software like Adobe Encore – not the cheap bundled software that comes with a DVD writer.     

Solid state video players, running from compact flash card memory are more reliable, and the price has fallen dramatically. I now run most of them with a player called a DV68, made by Medeawiz. (£165 + £35 for a switch keyboard for accessing 8 different tracks). It works perfectly.   

HD TV is now possible, and its good for arcade machines as people are watching the screen close up. However there are many electronic 'hot spots' which degrade the image between the camera and the final edited film on HD TV. Buy everything you need at the same time and try it out quickly so you can send it all back if the final image isn't HD quality. I'm still waiting for things to improve.

Video Monitors

It is not completely straightforward to get a TV set to switch on and find the right channel automatically.  Most TVs switch on to standby mode, so I add a delayed pulse timer (RS 365-6993), giving it an initial pulse contact to the channel+ button. Most TVs switch on the channel that was on when the set was last switched off. 
I have tried open frame industrial monitors, which are much more convenient because they have glass screens and switch on automatically when the power comes on. The downside is that they are much more expensive and in my experience not as bright as ordinary TVs.

Computers

I’ve tried incorporating a PC in two coin op machines. In one (the Gene Forecaster), I wired into the mouse button. This simply started a macromedia director movie. The start menu can also be set to launch any program automatically.

In the other machine  (my Expressive Photobooth) other I wired external switches to 5 of the keyboard switches. Macros, called actions in photoshop, are then triggered by the keyboard switches. This is a powerful technique which has all sorts of possibilities for making elaborate machines without any programming language skills.

 The disadvantages of using home computers is that when something does go wrong, there are so many levels of complexity that it’s very time consuming and expensive tracing faults. Perhaps I should be less pessimistic as the major faults I spent years tracking down weren't buried too deeply.  One was simply caused by inadequate cooling – the computer was inside the machine housing. The others were caused by inadequate shielding round the keyboard interface circuit and a buggy Logicec webcam driver. However the enormous amount of time it took to pin down these faults really put me off. I recently rebuilt the Gene forecaster with a video player instead of a computer, and its worked perfectly ever since.