RQDXn to RX33 / RX50 cable construction

While perusing the 'net the other day, I stumbled across details for a cable to go directly from an RQDXn controller to a hard drive. I didn't find any mention of a cable to go from an RQDXn to a floppy. Since I have a BA123, and ONLY use the RQDX3 for floppy support, I thought it might be a handy cable to have, rather than going through the tangle of cables involved with the RQDX "Paddle card". It might also come in handy for testing. If anyone is interested, here are the pinouts, and instructions for constructing such a cable.? The instructions were created with the lay-person in mind.? Copying this text into Windows Notepad should restore proper formatting. This cable was constructed using a BA23 distribution panel as a guide, and has been tested with both RX50's and RX33's, attached to an RQDX3. Cable diagram: Floppy? RQDX??? Description --------------------------------- 1?????? 21????? Gnd 2?????? 22????? Density Select --------------------------------- 3?????? NC????? (Cut) 4?????? NC????? (Cut) 5?????? NC????? (Cut) --------------------------------- 6?????? 24????? Drive Select 4? 7?????? 25????? Gnd 8?????? 26????? Index 9?????? NC 10????? 28????? Drive Select 1 --------------------------------- 11????? NC????? (Cut) 12????? 29????? Drive Select 2 13????? NC????? (Cut) --------------------------------- 14????? 30????? Drive Select 3 15????? NC 16????? 32????? Floppy Motor 17????? 33????? Gnd 18????? 34????? Direction 19????? 35????? Gnd 20????? 36????? Step 21????? 37????? Gnd 22????? 38????? Floppy Write Data 23????? 39????? Gnd 24????? 40????? Write Gate 25????? 41????? Gnd 26????? 42????? Track 0 --------------------------------- 27????? NC????? (Cut) 28????? 8?????? Write Fault --------------------------------- 29????? 45????? Gnd 30????? 46????? Floppy Read Data 31????? 47????? Gnd 32????? 48????? Head Select 0 33????? 49????? Gnd 34????? 50????? Ready Stuff you'll need: 1.)???? A suitable length of 34-conductor ribbon cable. ??????? Make sure you have enough wire to reach the controller, ??????? and enough slack on the other end to allow the drives ??????? to slide out of the bay.? Add 6" onto this measurement. 2.)???? A 50-pin IDC-style "Berg" connector for the RQDXn. 3.)???? A 34-pin IDC-style "Berg" connector for an RX50. 4.)???? One or two 34-pin IDC-style card-edge connectors for RX33's. What to do: 1.)???? Split one end of the ribbon cable as follows. ??????? DON'T separate ALL of the wires individually; keep them paired! ??????? Peel each grouping of conductors back about 4 or 5 inches. ??????? 1,2 ??????? ------------- ??????? 3,4,5 ??????? ------------- ??????? 6 through 10 ??????? ------------- ??????? 11,12,13 ??????? ------------- ??????? 14 through 26 ??????? ------------- ??????? 27,28 ??????? ------------- ??????? 29 through 34 2.)???? Cut conductors 3, 4, 5, 11, 13, and 27. ??????? They won't be used, and there won't be a convenient place ??????? to terminate them on the connector. ? ??????? These wires will need to be insulated at some point. ??????? If you have wide plastic sleeving, then put a section of it ??????? onto the cable.? Heat shrink will NOT work well. ??????? A simple loop of electrical tape should suffice. 3.)???? Conductor 28 needs to be fairly long, since it ??????? lands on the opposite side of the 50-pin connector. ?????? ?Trim about 3 inches off ALL of the OTHER wires. 4.)???? Using a pair of needle-nose pliers, ??????? REMOVE the following contacts from the 50-pin IDC connector: ??????? 7, 9, 19, 20, 23, 27, 31, 43, and 44. ??????? This will prevent certain RQDXn signal lines from ??????? being inadvertently grounded, and will help properly ??????? identify your landing positions for some of the connections. 5.)???? Line up the ribbon cable with the connector, ??????? and check to make sure that conductor 28 is long enough ??????? to reach across the cable, without placing it under any strain. 6.)???? Press the ribbon cable onto the 50-pin IDC connector. ??????? Refer to the chart at the top of this text; You'll see ??????? that they are grouped exactly as they should sit on ??????? the actual connector, with the exception of conductor 28. ??????? Note that SOME groupings start on ODD connector numbers, ??????? and some start on EVEN numbers. 7.)???? If you haven't done so already, refer back to step 2, ??????? and insulate the wires that were cut, to prevent them ??????? from shorting-out against the chassis. 8.)???? Determine where you need your floppy connectors, ??????? and press the connectors onto the 34-pin cable. ??????? Make sure that you observe the position of Pin 1. ??????? I made a "Universal cable" for my BA123. ??????? It has a 34-pin berg, and TWO card-edge connectors ??????? near the end (spaced about 4" apart), and then a THIRD ??????? card-edge connector about 10" down. ??????? This will allow double-stacked RX33's in a single bay, ??????? individual RX33's in separate bays, or a single RX50. 9.)??? ?Test, and enjoy ! ________________________________________________________________________ More new features than ever. Check out the new AIM(R) Mail ! - http://webmail.aim.com