Ira Burton wrote: > I appreciate the approach Olin took on this. When I read the original > post, I began to worry that all my designs that use an RJ-12 connector were > somehow flawed. It took me about 15 minutes of thinking about the jack to > decide my fears were unfounded and that I had temporarily allowed the OP to > anchor me with a negative opinion of the jack. > > Olin is dead right about the connector. It is very reliable, and the last standard from bell systems was that the contact point must be gold. I believe it would be hard to find a better connector. My complaint is from the wires that must be used with the RJ-12. I also agree about PGD and PGC being next to each other; a ground seperating them would not only improve crosstalk, but it would also halve the GND resistance, a serious problem. As a result, I always have the cable VERY short in length (about 6"). --Bob > On 10/25/06, Olin Lathrop wrote: > >> Rolf wrote: >> >>> For the record, I figured Olin's pedantic reply about his ICD2 not >>> having an RJ12 plug was worth investigating, and it appears he is right. >>> >>> ICD2 s do NOT have RJ12 jacks. There apparently is no such thing >>> specified. An RJ11 jack is a 6p2c modular plug, an RJ14 is 6p4c, and an >>> RJ25 is 6p6c. >>> >> This is not what I was trying to point out. I said I don't have a ICD2 >> with >> a "ridiculous RJ12 jack" as the OP asked about. Mine all have regular and >> quite reasonable RJ12 jacks. >> >> I didn't like the way the OP was asking for help and at the same time >> putting words in anyone's mouth that might help him. His question was a >> lot >> like "Have you stopped beating your wife?". Anyone responding to the OP's >> question would be implicitly agreeing that the ICD2 connector is >> "ridiculous" and that "everyone knows" that. I thought that was arrogant >> and a particularly obnoxious way to make a point, so I responded to his >> post >> in a way that was litterally correct but otherwise useless. >> >> If the OP thought a RJ-12 was the wrong choice for the ICD2 connector he >> should have stated that as his opinion and provided some support for his >> argument, instead of just calling it "ridiculous" and implying everyone >> agrees with that. >> >> For the record, I think RJ-12 was a reasonable choice. It is quick to >> connect and disconnect, locks with a positive feel, can't be plugged in >> backwards, cheap, and widely available. These connectors have proven to >> work well in nearly 30 years of telephone use. >> >> The one part of the design I don't like is the pinout. PGC and PGD are >> next >> to each other. This invites crosstalk, and I've presonally seen it >> happen. >> At the time of the design, Microchip was vaguely planning the last pin for >> PGM, but that was never implemented. In hindsight it would have been much >> better to separate PGC and PGD with a extra ground wire. All my >> programmers >> have a RJ-12 jack for compatibility, but also a 6 pin header and/or pads >> with the extra ground line between PGC and PGD. For programmers built >> into >> fixtures, I always recommend the 6 pin interface be used instead of the >> RJ-12, but not because there is anything wrong with a RJ-12 jack. >> >> >> ******************************************************************** >> Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products >> (978) 742-9014. Gold level PIC consultants since 2000. >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> >> -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist