You probably saw someone selling an original Photon POD on E-Bay, or you “knew a guy” who let you smuggle one out of a closing Photon, and it’s been sitting in your basement for 20 years. Every once and awhile you see it and connect it to some kind of power supply (hey, you might even have an original diving^Wbattery belt who you were able to get charged.) The bloop-wheep-woop of a freshly plugged in POD is just that bit of nostalgia you needed — but you’ve always wanted more. You want to here the phaser fire. You might even want to hear the sound of a hit (or , as you remember, more often as you remember, a miss or the crushing sound of hitting someone on your own team.) If that’s what you need…
How to Make a Photon Entry Terminal
If you read my last post, “So, you want a modulated IR signal, and you’re too damn cheap to do it right,” you already have part of the answer to that puzzle. However, you’ll need some more bits (or bytes) to successfully fake the functionality of the entry terminal.
What does the POD need to play a game?
The Photon POD gets three pieces of information from the entry terminal:
- IR Code for this POD
- RF Slot Number for this POD
- Game Mode
Sending the IR code AND slot number seem a bit redundant, since one is calculable from the other — but that’s how it was done. If you’ve read the previous articles, you know what these bytes should be. The Game Mode is new, and instructs the POD as to the game type (Public, League, & Free For All) and the number of fields in play (either a single field, or dual field setup)
Wait, what’s a dual-field setup?
Most Photon centers were single-field, but some (such as Chicago Harvey) were lucky enough to have TWO fields. Both of these fields would run games synchronously (starting, and ending at the same time.) To keep things straight, when the dual-field mode is enabled, even-numbered IR codes (and “slots”) ware associated with field 1 (the Alpha field), and odd-numbered IR codes are associated with field 2 (the Omega field.) If you try to shoot someone who’s entered in for the other field, “your phaser won’t work.” (well, it’ll just register a miss.)
Also, on game modes.
Two dimensions of the POD’s behavior are affected by the game mode. One is the length of time a hit registered on this POD will cause the phaser to be deactivated for. You remember from a previous article, the game computer has certain transmit slots to send data to the PODs. When the game computer transmits a POD’s IR code in one of those slots, it’s an indication to the POD that it has been shot, and it will deactivate it’s phaser for some period of time — and give you that nice WHOOP WHOOP sound that you remember fondly. In League and Free For All mode, this duration was a static 5 seconds. In Public mode, a simple handicapping strategy was in effect, and the phaser’s downtime was calculated within a range of 2 to 9 seconds — based on the ratio of hits and “got hits” as tracked by the POD.
The second dimension involves Free For All mode. In Public & League modes, when you were to hit someone on your own team, your POD would transmit the IR code of itself to indicate it had hit it’s own player. The game software would deduct 30 points, and transmit back to the pod it’s own IR code which would cause it’s phaser to be disrupted (this was a great way to test if the POD’s radio was functional, since you quickly got notification of a successful transmission & reception!) In Free For All mode, you could “hit” anyone regardless of team, and it would send the IR code of the player to the game computer. (will cover some interesting shenanigans possible here)
|Single Field||Dual Field|
|Free For All||0xc3||0xE3|
JUST SHUT UP ALREADY! I’ve got your damn IR software working, and this POD sitting here all turned on. THE BATTERIES WON’T LAST FOREVER!
Damn ya’ll are impatient. A 6-byte repeating sequence is required to activate a POD:
- 0x9d (aka BARKER)
- 0×62 (aka NOTBARKER)
- Pod’s IR code
- Pod’s RF Slot #
- Game Mode
- Checksum (calculated as BARKER ^ ~BARKER ^ IRCode ^ Slot ^ Mode)
For example, to enter someone in to red slot 5 in a public game on a single field — “red 5 standing by” — you’ll want to send:
0x9d, 0×62, 0×46 (0×42 + 4), 0×08 (0×04 + 4), 0xC1, 0x0D (that checksum thing)
Send that via IR to the pod a few times repeated, and, your pod might* work.
* Your POD will need a GR16 or greater version of the ROM. Otherwise, try the “dual field” game mode!