DESCRIPTION: �컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� I have designed and am now testing a special cable that allows you to transfer to the Game Server and back to the BBS without using passthrough. As you have figured out with the passthrough you need 8 digiboard ports to run a 4 node BBS, one port to the modem and one port to the BBS, it gets expensive to addon more nodes later. My cable is rs232 line powered, no external power supply needed, gets all it's operating power from the modem DSR line. It's small, about the size of a matchbox, contains many small solidstate parts, and works well. I'm trying to locate parts vendors now and should be able to produce cables in about 3 weeks. One added benefit of these is that you can shut down the Game Server without shutting down the BBS, it will continue to operate and the custom 'switch' cables will prevent anyone from switching when the GS is offline. Can you say 'neat feature?', sure, I knew you could :) *** FOR PCBOARD Systems ONLY *** (Unless APCi or someone writes a 'switch routine DOOR' to access the switch) Cost for each cable is going to be around $40 ready to plug and go. Due to the fact that the relay is a custom ordered device with the minimum factory order being 50 pieces, the diagram will be of little use without it and is no longer being offered. �컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� THEORY of OPERATION: Inside this little gem are two almost identical circuits. The custom 4PDT (4 pole, double throw) latching relay has two coils, activating one coil switches all 4 poles one way activating the other switches all 4 poles back. All we need to switch is the RS232 signals RD/SD and CTS/RTS, Pins 2,3,4 & 5. The two circuits consist of a charge pump and two timing configurations. One timer is set for ~ 5/18ths of a second, the other for ~ 10/18ths of a second. They are triggered by the DTR lines coming from the BBS and the GameServer. The BBS DTR normally drops for about one second when PCBoard hangs up and recycles (~18/18 second or 1 second). When the switch detects a DTR drop, the timers both start, the short timer pulls the modem over to the GameServer. The long timer pulls it back to the BBS as both timers expire under one second. Now here's the trick, to drop DTR from the BBS for a period of time greater than the short timer but less than the long timer, see what happens? The short timer pulls the modem to the GameServer and we raise DTR to stop the long time dead before it times out, viola! we have swithed the modem to the Game Server, time to play DooM!. Now when done on the Game Server a user just presses 'X' to exit, and the Game Server drops DTR for the amount of time set in the Game Server "drop DTR for this long" configuration option. Two seconds is a good setting. Now this DTR DOES NOT go to the modem, the modem belongs to the BBS and is only on loan to the Game Server! The BBS has total control of the modem at all times!. The Game Server DTR line goes only to the switch, and when it drops, it starts those timers and as long has DTR stays down for at least one second, the relay goes CLICK - CLICK and the modem ends up back to the BBS. Now the guy in the back has his hand up I see, "what stops the modem from hanging up when the BBS drops DTR for 5/18's of a second?" A very good question. Well, there just happens to be an 'S register' to set DTR response time in the modem, S25 in all I have checked so far. It defaults to around 5/100 of a second but can be set from 1/100 of a second to 255/100 of a second (2.55 seconds), see what now?? Sure you do, we set this value to just over the time that is takes for the long timer to expire, but less than the one second that the BBS is going to drop DTR. I have found 70/100 to 80/100 works, just under one second but longer than the long timer. When the BBS drops DTR for one second, you should hear CLICK-CLICK and then the modem should hang up. The first click is the modem going to the GS, the second click is the modem coming back to the BBS and if DTR is still down at this time, the modem should time out and hang up. It works for me, but not having every brand of modem to test it on, I can't promise anything. Each cable is custom made to order, there are not any in 'stock' to say, if you want one or more to try, order them and i'll build them. It takes about 8 hours to build 4 (Saturday :) If your not happy with them, send 'im back. I'm not a hard-ass :) WizBandit! Modems tested and known to work: USR v.32terbo USR v.34 Hayes Accura 14.4 Hayes Optima v.fc & v.34 �컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�