Chipcom had a series of telco ethernet modules that were part of the ONline hub product line. They supported either 12 or 24 ports, and some modules supported fault-tolerant switchover.
Here is a description of during the 3Com years, when ONline was renamed "CoreBuilder 5000" The CoreBuilder 5000 Ethernet 24-Port Module is an IEEE 802.3 repeater module that complies with the 10BASE-T standard. It connects up to 24 devices (PCs, terminals, printers, modems, etc.) to the CoreBuilder 5000 hub. Two 50-pin Telco-type connectors connect to 24 10BASE-T-compliant ports using 25-pair 10BASE-T cables or 12-leg "hydra" cables. ---- Original message ---- >Date: Wed, 2 Nov 2011 11:23:03 -0400 >From: [email protected] (on behalf of "Ricker, >William" <[email protected]>) >Subject: Re: [Discuss] OT: what is this cable for? >To: Dan Kressin <[email protected]>,BLU Discuss <[email protected]> > >> Ribbon cable w/ two (the name escapes me ..) "ring things" to usually used >>to fight inductance.. > >Snap-on Ferrite donuts actually *add* inductance, which rounds the corners of >square wave digital signals, to prevent interference (both by and to) and/or >induced spikes from lightning EMP. They come in a variety of specs which >attenuate into progressively lower frequencies. Use the wrong one and you'll >attenuate the desired signal too ! > >(One more pedantic than I might object that fighting interference is fighting >*mutual* inductance, but that's not a measurable inductance outside of >cross-talk range.) > >Yes the DA-15 was used as Game/MIDI port on early IBM PC ISA sound cards. But >the normal MIDI adapter cable would have been DA-15 to pair DIN-5 (or XLR3). >Since the game port was re-used to drive all sorts of things, that's a >possible origin, as are any custom frobistats. The C-50 / CN-50 was abused as >an easy expansion interface for lots of pre-miniaturization devices -- it was >originally a family or range of telco analog connectors for twisted pair >snakes, eg multi-line phones & PBX to punchblock cabling, that was adopted for >printers, re-adopted for SCSI-1, because it was available relatively cheap due >to volume of telco use. As the RJ series has been adopted more recently. The >C-36 had obscure computer uses, not sure if larger sizes were ever digitally >'appropriated'. > >Bill @ $DayJob >_______________________________________________ >Discuss mailing list >[email protected] >http://lists.blu.org/mailman/listinfo/discuss _______________________________________________ Discuss mailing list [email protected] http://lists.blu.org/mailman/listinfo/discuss
