------------------------------------- VB Link Notes By David Tucker (david.tucker@goliathindustries.com) ------------------------------------- Hear are some mail messages I wrote to another indavidual who was trying to figure out the Link Port. There kinda one sided (I commented out his replies, nothing interesting there). Many people have asked me about this, I feal that there is a real good posibility that one or two games (Telero Boxer and Mario Tennis) could use the link port, but I was unable to verify this... It is also posible that the 8 or so games that are not booting on the emu could use the link port as well (Including panic bomber) but again I have no way to tell... Id strongly encourage you to build an experimental link port and grab a second system (The cost is so low, you can get a VB and games for less than $35) and see what you can do! I have tried once to make a link port, but gave up, I have to many projects right now and the link port cable is just not top on my list (Sory =0). Rest ashured, if I ever do get bord and I fgure it out Ill let you know. (Snips from past emails, dont hold your breth!) ----------------------- What I have on the Com Port: Com port Communication is syncronized using a 50KHz clock, between a Master and Slave unit. The master unit transmits the Clock. Data is sent in 8 bit groups. There is a Com Controll line (in/out), Read Line, Transmit Line. That is it. In summary there should be the folowing 6 lines Transmit Line Receve Line Clock Line Controll Line Power and Ground Game Boy -------- /------------\ / 5 3 1 \ | --- --- --- | |---------------| | --- --- --- | | 6 4 2 | Game boy Link connector, looking at the gameboy --------------- (Use your Imagination) Pin # Usage ----- ----- 1 +5 Volts 2 Send 3 Recive 4 ???? (unused output line) 5 Clock 6 Ground Link Cable ---------- 1 1 2-------\/------2 3-------/\------3 4 4 5---------------5 6---------------6 (2 goes to 3, 3 goes to 2, 5 to 5, and 6 to 6) Virtual Boy ----------- /-----------------\ / 1 2 3 4 \ | --- --- --- --- | |--------------------| | --- --- --- --- | | 5 6 7 8 | Virtual boy Link connector, looking at the VB -------------------- (Use your Imagination) Pins (What #'s???) ------------------ (Send) ---\/--- (Recieve) (Recieve) ---/\--- (Send) 6 (Clock) -------- 6 (Clock) 7 (Ground) -------- 7 (Ground) (ComCntrl) -------- (ComCntrl) 2 (Power) (unconected) (Unused1) (unconected) (Unused2) (unconected) Link cable ---------- send goes to recieve on other VB and recieve goes to send... clock to clock, ground to ground, and ComCntrl to ComCntrl... that leaves 3 wires (Power and the 2 Unused) they must not be connected (I think)... Telero Boxer and Mario Tennis both write to the comm port, they both might support Link cable games??? (Untested) all other games that are working on the emu do NOT write to the comm port and do not use the link cable (This includes Space Squash, thought to be a Link game) My recomendation is to try all posible combinations (hooking 3 wires strait acrost and crossing the last 2) If you assume that pin 7 is ground you neever need to move it, so you only need to try moving the 2 straight wires (theres only 5 posible places they can go) and the 2 crossed wires (again only 5 posible combinations). If I have time Ill try this out myself... Id recomend trying Telero Boxer, it writes often to the link port. And Tennis only writes once... I put in the Game Boy stuff for reference... (Its a good example of how a real system works) (New) I hooked the scope up to the link port finaly, Pin 6 is definently the clock, 7 is the ground, and 2 is Power (+5v). Pins 1,3,4,5 all have +5v on them, and pin 8 is at ground. Pin 1 was teh only pin to change, it went from High to low in MarioClash, I dont know if this is significant or not? No games activly changed the link port lines (except for the clock) I dont know if this meens that no games support the link cable, or if the cable needs to be hooked up for things to work? This definently needs a second look... David Tucker david.tucker@goliathindustries.com