PDP-11 Controller needed to use a couple of RX33 drive

Jerome Fine replies: Since I am not familiar with the above solution and I don't have the hardware knowledge to evaluate if it can be done, I will not comment. However, my personal experience with TWO RX33 floppy drives connected to an RQDX3 is as follows: (a) First, it is necessary to use an RQDX3 with the firmware revision which supports the RX33 floppy drive. I am not sure what the required firmware revision level is supposed to be, but I am fairly sure that the very first RQDX3 controllers did not support the RX33. Most likely, however, support for the RX33 was made a feature of the firmware since I did not have a problem with the RQDX3 that I used to support my dual RX33 drives. (b) Second, I suggest that a test of the RQDX3 controller that will be used be performed by using an RX50 dual floppy drive unit. If the RX50 dual floppy drive unit works, then it is very likely that the RX33 will work. (c) You will require a different end connector for the cable at the RX33 since the the RX50 uses a single header and the RX33 requires two 34-pin edge connectors daisy chained from one RX33 to the next WITHOUT any modification of the cable between one RX33 drive and the next RX33 drive (as is normally done with a PC when two floppy drives are used). (d) The e-mail from Zane Healy on February 5th, 2008 is copied below to provide the jumper settings needed, in particular the DS0 and DS1 to allow the RQDX3 to select the specified floppy drive unit. (e) Just a helpful suggestion to provide an enclosure for the dual RX33 drives: I found a non-working RX50 dual floppy drive and used the empty case to hold both RX33 drives. The access slots in the case allowed both the power cable the 34-pin cable. The power cable was connected to a Y-power cable splitter inside the enclosure. The two 34-pin edge connectors were daisy chained to the RX33 drives before bolting the RX33 drives to the enclosure from the RX50 dual drives. The sled underneath the enclosure was retained as well and fits very nicely into the BA23 box. The results looks very much like the dual RX50 floppy drives at first glance until the handles of the RX33 drives are recognized. In addition, my personal preference was to situate both RX33 drives in the upright position as opposed to the RX50 having one drive upside-down. If you have any other questions, please ask. Sincerely yours, Jerome Fine ------------------------------------------------------------------------------------------------------------------------- =========================================================================== ===== Note 93.3 Low-end disk devices - The Digital difference 3 of 136 EISNER::KENNEDY "Terry Kennedy" 72 lines 16-JAN-1988 02:05 -< RX33 >- --------------------------------------------------------------------------- ----- The DEC RX33 is an IBM AT-type drive with some jumper changes. DEC's drive is some variant of the TEAC FD55G. I have exper- imented and discovered that the following drives/jumperings work with the RQDX3: TEAC FD-55GFV-17-U Jumpers in: HG I (Roman numeral 1) U1 U2 DC FG DS0 (for first RX33) DS1 (for second RX33) Jumpers out: (all others) Install the terminator, RA1, on the last (or only) drive TEAC FD-55GFR-540-U Jumpers in: I (Roman numeral 1) U0 U1 DC2 FG D0 (for first RX33) D1 (for second RX33) Jumpers out: (all others) Install the terminator, RA1, on the last (or only) drive Toshiba FDD 6882E1J01 (or ND-08DE-G) Jumpers in: LD DC DE D1 (for first RX33) D2 (for second RX33) Jumpers out: (all others) Install the terminator jumper, TM, on the last (or only) drive I have purchased many of the TEAC 540 drives from JDR Micro- devices in California, (800) 538-5000. They have the follow- ing items of interest: [NOTE: This is *old* info (1988) and probably isn't valid any more] FD-55G High density drive - $129.95 FD-5Y 'Y' cable to power 2 drives from the BAnn box - $2.95 FD55-MHW Mounting hardware for two FD-55G drives - $2.95 FD55-FP Beige faceplate for FD-55G drive (black is std.) - $2.95 FD55-SPEC Specification for FD-55G drive - $5.00 FD55-MAINT Maintenance manual for FD-55G drives - $25.00 Therfore, you can get two RX33's for $265.80 with the Y cable and mounting hardware - a far cry from DEC's $795.00 each... You need an RQDX3 to run these drives, of course. You will also need to save the skid plate from your RX50 drive. If you order these drives elsewhere, please remember that the mounting hole threads are *metric*. Finding the right screws will be a lot harder than finding the drives! =========================================================================== ===== Note 93.77 Low-end disk devices - The Digital difference 77 of 136 EISNER::KENNEDY "Terry Kennedy" 15 lines 19-JUL-1991 01:40 -< Newer Teac model for RX33 substitute >- --------------------------------------------------------------------------- ----- A number of people have asked me for other RX33 substitutes, since the Teac models I gave earlier in this thread are no longer available. I did some experimenting and I have a new one for you: The Teac FD-55GFR-149-U can be used as an RX33 by installing jumpers on FG, DC, I, and D0 (for 1st drive) or D1 (for 2nd drive). The "I" jum- per is hard to find - here's a picture: LG o o IS o o o<---- This is the "I" jumper o<-/ DC o o o o o o o I've tested this with RX50 and RX33 media under XXDP+ and RSTS/E. Terry Kennedy Operations Manager, Academic Computing te... at spcvxa.spc.edu St. Peter's College, Jersey City, NJ USA +1 201 915 9381 (voice) +1 201 435-3662 (FAX)