Date: Tue, 19 Mar 91 10:02:50 -0500 From: cyliax@ecn.purdue.edu (Ingo Cyliax) To: rees@citi.umich.edu (Jim Rees) Subject: Re: Want to change 8 inch floppy to 5 inch A 1.2Mb 5.25" floppy drive has the same rotional speed as the 8" floppies (360rpm). It does have the 34pin connector and not the 50pin connectors that the 8" floppy has. It should be possible to make a special cable to convert the 50pin floppy controller interface to the 34pin floppy interface required by the 5.25" drives. Most of the signals are the same, although there are some additional signals on the 8" interface that may or may not be used by some drives. Hope this helps, -ingo -- /* Ingo Cyliax ECN, Electrical Engineering Bldg. * * cyliax@ecn.purdue.edu Purdue University, W. Lafayette,IN 47907 * * cyliax@pur-ee.UUCP Work: (317) 494-9523 * * cyliax@flaubert.laf.in.US Home: (317) 474-0031 */ Date: Tue, 19 Mar 91 12:45:54 EST From: cyliax@ecn.purdue.edu To: rees@citi.umich.edu (Jim Rees) Subject: 8" Pinouts Pin SA450 SA850 ----------------------------------- 2 density RWC 4 inuse/headload - 6 sel4 - 8 index - 10 sel1 2sided 12 sel2 - 14 sel3 side 16 motoron - 18 direction headload 20 step index 22 wrdata ready 24 wrgate - 26 trk0 sel1 28 wprot sel2 30 rddata sel3 32 side sel4 34 ready direction 36 - step 38 - wrdata 40 - wrgate 42 - trk0 44 - wprot 46 - rddata 48 - - 50 - - Date: Thu, 28 Mar 91 19:15:59 MST From: tom@as.arizona.edu (Thomas J. Trebisky) To: rees@citi.umich.edu Subject: Re: Want to swap 5 inch to 8 inch floppy Newsgroups: comp.os.cpm In-Reply-To: <50a3eb06.1bc5b@pisa.citi.umich.edu> Organization: University of Arizona, Tucson, AZ In article <50a3eb06.1bc5b@pisa.citi.umich.edu> you write: >This has nothing to do with CPM, but I understand you guys are the experts >on floppy drives. I've got a computer (Apollo dn330) that has an 8 inch >floppy drive that I want to change to a 5 inch. The 8 inch has a capacity >of 1.2 Mb, something like a st506 interface (sa850?), and a 50 pin card-edge >connector. I've got pinouts for the 50-pin and also for the 34-pin >connector used by the 5 inch drives. ST506 has nothing to do with it, that is a MFM hard drive interface. SA850 sounds better! In fact I am just thumbing thru a Shugart 850/851 manual. (That is indeed an 8-inch floppy 850 is single sided, 851 is double). Is the drive in your whatever it is, a Shugart 850 or 851 ? (We had some Data General CPU's with 8-inch drives with wierd interfaces designed on mars -- no hope of ever putting anything into them (but those old turkeys got scrapped.....)) If yours has the standard 8-inch interface.... >I'm told that the rotational speed is the same, and I know the sector layout >is the same, so I'm assuming that bit rates and signal timings will just >fall out for free. I don't think the speeds are the same (I think 300rpm for 5.25 inch, and 360 for the 8 inch). But I am probably wrong. > >1. Will this work? I bet you can pull it off, there has been a lot of discussion about doing this kind of thing here. One key note -- the 8-inch has a 500kb/s data rate, your low density 5.25 inch has a 250kb/s data rate - so you cannot use an ordinary 5.25, you must use a 1.2Meg 5.25 (as they put in AT's), or better yet use a 3.5 inch 1.44Meg drive - you will get 1.6M out of it, or whatever your 8-inch has been giving you. I have cable details somewhere in a stack of papers over yonder to connect an 8-inch controller to a 3.5 inch drive. (or a 5.25 inch) > >2. Is there any chance this will just plug-n-play, or will I have to muck >around with the device driver in the OS? You can make it plug and play if you do it right. > >3. What do I do with pin 2 (density) on the 34-pin? I assume tie it high >or low -- which is it? > >4. What about pin 16, motor-on? Should I tie this high or low, or tie it >to pin 4, head-load? > >5. What is pin 2 on the 50-pin, RWC? What should I do with it? Reduced Write Current >6. Any tips on shopping for a 5 inch drive? Will any drive with the 34-pin >(sa450?) connector work, as long as it's a 1.2 Meg drive? How much should a >floppy cost? The local repair shop has one for US $60, is that OK? Doesn't sound like a bad price -- here is some advice, based on past traffic in this group. You can use a HD 1.2 Meg drive (5.25inch) to replace the 8-inch if you set it to high density. A better bet might be to go to a 3.5 inch drive -- believe it or not this may be easier (and better technology if you ask me!!). I'm going home - write me if noone else fills in the gaps. -- Tom Trebisky ttrebisky@as.arizona.edu (Internet) Steward Observatory University of Arizona Tucson, Arizona Date: Fri, 29 Mar 91 11:37:43 MST From: tom@as.arizona.edu (Thomas J. Trebisky) To: rees@citi.umich.edu Subject: Re: Want to swap 5 inch to 8 inch floppy You may have just gotten a bogus mail piece from me, ignore it. Pin 2 (RWC) is indeed a signal from controller to drive, so ignoring it sounds safe to me. OK, one 8-inch drive manual I have here says 360 rpm. A tandon TM-100 (your generic full-height 360K drive 5.25) says 300 rpm. Now my Teac 5.25 manual sez they run 300 rpm at normal speed and 360 rpm at "high" speed. Now for pinouts -- I just dug out a pile of printouts (stuff off the net, there was a big discussion about replacing 8-inch drives about a month ago, so I am just a middle man, but here you go......) A 5.25 inch HD or a 3.5 inch is electrical near equiv. of an 8-inch. Some 5.25 inch drives switch to 360rpm, but not all, apparently the TEAC can switch (if jumpered to do so!!). 34P 50pin ------------- 2 18 Head load (???) 4 12 Disk Change 6 32 DS3 8 20 Index 10 26 DS0 12 28 DS1 14 30 DS2 16 -- Motor on 18 34 Step dir 20 36 Step pulse 22 38 Write data 24 40 Write gate 26 42 Track zero 28 44 Write protected 30 46 Read data 32 14 Side select (some 8-inch drives are wierd here) 34 22 Ready (Not all 5.25 inch drives have this) Note - this worked for one fellow, but each drive seems to have non-standard features and jumper options. A number of theories exist about how to do motor on -- the best suggestion seems to be to hook it to ground (most 5.25 inch drives spin only when a disk is in and the door is closed). Pin 2 is the odd-ball -- For the Teac it is the High/Nornal density select but you will have to check for whatever drive you end up using. Best of Luck ... Tom Date: Fri, 29 Mar 91 14:29:05 -0500 From: Wayne Sung To: rees@citi.umich.edu Subject: Re: Want to swap 5 inch to 8 inch floppy If you're able to pick up a 1.2 MB drive for $60, you ought to do it. There is one other possibility: 3.5 inch. Let's see: I just changed a pair of 8's to 3.5's and although the change did not occur totally cleanly the problem was an electrical one on the disk controller (and really didn't even affect the 3.5, only the simultaneous use of 3.5 and 5.25 regular). I also believe the 3.5 HD disks to be better quality and possibly cheaper than the 5.25 - I have had numerous failures of the 5.25 and almost none on the 3.5 (in particular the 5.25 seems to have problems with different drives). This of course assumes you have a choice. In terms of the connections, if you keep the motor running you can also keep drive ready on. This is a tossup - 8 inch drives usually had head-load solenoids so keeping the motor running is not a problem. With 5.25 you want to be sure the drive has one. I've seen some either way. With 3.5 unfortunately there is no choice. RWC (low current) does not exist on the smaller drives (that is, anything beyond the very first 5.25 inch drives). Be sure you rig up a way so that one each can run at the same time so you can convert your disks. There shouldn't be any os mods necessary, although an 8 inch drive uses 77 tracks and the smaller ones 80 tracks so you can technically reclaim 3 tracks. This is easy in cp/m, but I have no idea how the drive declarations work in your case. Other than that, if they did a good job anticipating the qualtities of floppy drives in general, it should work. Some other people had commented that if you don't keep the motor running (using drive select instead) most of the time the retry mechanism will allow that anyway. Date: Fri, 29 Mar 91 23:27:10 EST From: vera@fanaraaken.Stanford.EDU (James S. Vera) Newsgroups: comp.periphs,comp.sys.apollo Subject: Priam 7050 Hard Drives and Apollo DN300 shoeboxes I recently began a search for facts about the hard drives in our Apollo DN300 shoeboxes. After much search I am reporting back on what (little) I have learned. First off the hard drive in my shoebox is a Priam 7050-41. As many of you know Priam is not quite what it used to be and it turns out that a company called Sequel (sp?) +1.408.987.1533 now handles the drives. Joe Grove in technical support told me the following: Drive Interface ----- --------- 7050-11 Priam Proprietary 7050-21 SMD 7050-41 ANSI X3.101 Kathy in Sales said she would sell me the interface board to change my 7050-41 to a 7050-21 for $500 and she seemed willing to deal (maybe $250). [if for some reason I was dieing for a small SMD drive the Minicomputer exchange sells an unused 84MB drive for $125]. Closure: 1) Unless it turns out that ANSI X3.101 to anything-useful converters these drives are probably boat anchors. 2) The rumor that the drives are ST-506 compatable is unfortunately almost certainly wrong. 3) Someone on the net sent me a list of the pin outs for the drive which he obtained from some Apollo literature. The pin outs did not exactly match the pin outs in the ANSI X3.101 literature. (Why? I dont know). Thats all I know. -- James S. Vera | Internet |Standard Disclaimers Stanford University|vera@fanaraaken.stanford.edu|Blah Blah Blah Blah Bellcore |vera2@rigel.cc.bellcore.com |vvv My WARNING vvv I am an ASSU Graduate Senator, Engineering & Earth Sci. Be Suspicious! Date: Sat, 30 Mar 91 12:26:29 -0800 From: James S. Vera To: rees@citi.umich.edu (Jim Rees) Subject: Re: Priam 7050 Hard Drives and Apollo DN300 shoeboxes In-Reply-To: Your message of Sat, 30 Mar 91 12:16:00 -0500. <9103301717.AA02310@pisa.citi.umich.edu> Here's the pin outs I have: James ------------- Table 1, Pin Assignments from ANSI X3.101 Signal Ground Pin Pin Signal Name Signal Source ---------------------------------------------------------------------- 1 Ground --- CONTROL BUS 2 10 Bit 0, Select Attn Device 0 Host/Device 3 10 Bit 1, Select Attn Device 1 Host/Device 4 10 Bit 2, Select Attn Device 2 Host/Device 5 10 Bit 3, Select Attn Device 3 Host/Device 6 10 Bit 4, Select Attn Device 4 Host/Device 7 10 Bit 5, Select Attn Device 5 Host/Device 8 10 Bit 6, Select Attn Device 6 Host/Device 9 10 Bit 7, Select Attn Device 7 Host/Device 11 12 Parity (optional) Host/Device 13 14 SELECT OUT/ATTN IN STROBE Host 15 16 COMMAND REQUEST Host 17 18 PARAMETER REQUEST Host 19 20 BUS DIRECTION OUT Host 21 22 PORT NABLE Host 23 24 ADDRESS MARK CONTROL (optional) Host 25 26 READ GATE Host 27 28 WRITE GATE Host 29 30 BUS ACKNOWLEDGE Device 31 32 INDEX Device 33 34 SECTOR/ADDRESS MARK DETECTED Device 35 36 ATTENTION Device 37 36 BUSY Device 39 38 READ DATA + Device 40 38 READ DATA - Device 42 41 READ/REFERENCE CLOCK + Device 43 41 READ/REFERENCE CLOCK - Device 45 44 WRITE CLOCK + Host 46 44 WRITE CLOCK - Host 48 47 WRITE DATA + Host 49 47 WRITE DATA - Host 50 Ground --- Date: Sat, 30 Mar 91 21:18:42 -0500 From: Wayne Sung To: rees@citi.umich.edu Subject: Re: Want to swap 5 inch to 8 inch floppy it's perfectly fine to tie motor-on to ground so that the motor keeps running. 5.25 drives generally don't have a specific line for headload. That is usually a jumper option so that headload follows select or motor on. If you tie motor on to be always on, you might want to experiment as to which option seems to work best for headload. If you jumper headload to motor on then functionally you have disabled it, because the head will always be loaded. If you jumper headload to select, it will be necessary for the software to realize this so that it waits a moment before reading. Since you have two of the same kind of machine, check the one that already has this size drive to see if the head clicks or not. Then set the other one accordingly. Date: Mon, 1 Apr 91 15:34:23 -0500 From: Wayne Sung To: rees@citi.umich.edu Subject: Re: Want to swap 5 inch to 8 inch floppy "inuse/headload" is an input to the drive. It means it can be configured to be the inuse pin, which really doesn't do much more than light the lamp on the front, or to be the headload pin, whereby you can load the head as a separate action from select. Normally I don't see why you would load the head if the drive is not selected (although I have seen systems that do exactly that). Either way, there should be some jumpers available so that neither function has to be specifically performed, i.e. inuse and headload can both follow select so that pin can be left open. Date: Tue, 02 Apr 91 08:49:24 +1000 From: ken@csis.dit.csiro.au To: rees@citi.umich.edu (Jim Rees) Subject: Re: Want to swap 5 inch to 8 inch floppy Reply-To: ken@csis.dit.csiro.au (Ken Yap) In-Reply-To: Your message of Mon, 01 Apr 91 13:38:00 -0500. <9104011838.AA01216@pisa.citi.umich.edu> Here it is. Have fun. Adding a 5 1/4" 1.2MB drive to a RS 16/6000 system: ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ The following information is provided by an individual and is not nor should be construed as being provided by Radio Shack or Tandy Cory. Radio Shack/ Tandy Corp has no obligation to support the information provided in any way. ------------------------------------------------------------------------------ NOTE: The following information was posted about a month ago. However, I posted a draft version and not the version I intended to, and only noticed this after receiving some inquires about it. The following information supercedes the posting with the date 28-Aug-88. Sorry for the error. P.S. Note: Sent this out but somewhere in the virus crisis it seems to have not gone anywhere. To those that are seeing it again, Sorry. Just press J. ---cut here--- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6000 > 4000 > 3000 Vol 1, No. 1 Utilizing 5 1/4" media on your Tandy 16/6000 computer system. 31-Aug-88 by Frank Durda IV If you have reached the point where you are having trouble getting 8" media, or getting the drives repaired or replaced, this may interest you. The following information will allow you to add or substitute 5 1/4" high capacity floppy drives for 8" double sided drives in your 16/6000 XENIX system. You can mix 8" and 5 1/4" drives, or chuck the 8" drives entirely. If you just want to look at the pay-back, pull out your handy Radio Shack computer catalog. Ten 8" DD DS disks cost $39.95. Ten 5 1/4" HD DS disks cost $34.95. If you buy your disks at those prices, it will take 20 boxes of 5 1/4" vs 8" diskettes to pay off the approx $100 drive. Since most mail order houses can get you ten 5 1/4" HD DS for less than $20, a 5 1/4" drive will pay back a lot quicker. In addition, most people would agree that 5 1/4" media quality is usually better than the 8" media available today. If you want to add 5 1/4" drives externally, you should obtain an enclosure to mount the drives in. These are available from numerous mail-order houses. One is AEROCOMP, 2544 West Commerce St, Dallas Tx 75212, P.O. Box 223957 and the order number is 1-800-527-0347. (Sorry, I have never done business with this firm, so I can't comment on their product.) They advertise an enclosure for two 5 1/4" drives. You could also order such an enclosure from Radio Shack National Parts (it was used for CoCo drives in recent years). Almost any high-capacity (1.2 Meg) drive can be used. I used Mitsubishi MF504B-347UA drives. For that particular drive, these straps should be set: TD MS SR-PM2 RI SB DSx Other drives that should be acceptable include TEAC 55G series drives. DSx should be set as you prefer. On a Model 16B and 6000 drive 0 may not be selected on the external connector. If you have two internal drives on a 16B/6000 and want to keep using them, your external drives must be DS2 and DS3. The last external drive must contain a terminating resistor pack. If you only have one internal drive, you may have three 5 1/4" external drives. Set the strap DS1 for the first drive, DS2 for the second, and DS3 for the third. If you have two internal 8" drives and you wish to disable one of them, it will be necessary to disassemble your 16B/6000, and disconnect power and data cables going to your second internal drive. If the terminating resistor pack is installed on the drive you are disconnecting, you must move the resistor pack to drive 0. By disconnecting the power, you will reduce the power consumption and heat load on your system. You must also add a jumper at E40-E41 on the main CPU board (under the card cage). This moves the DS1 signal to the external connector. If you have a Model II or 16A, you can have at least two external drives and as many as four if you decide to disable the external drives. Initially it is suggested that you leave drive 0 as an 8" drive until you can copy your installation floppies onto 5 1/4" media. On the Model 16A, 16B and 6000, it is advised that you leave one internal drive connected to power even if you decide to disconnect its data cables. This is to insure a minimum load on certain power supply voltages. You must construct the cable between the Model II/16A/16B/6000 and the 5 1/4" drives. You will need a 50 pin dip connector and at least one 34 pin edge connector (one per drive). You may use either 34 or 50 pin wire. If you have an existing 50 pin cable and a 34 pin cable, you may simply wish to cut the connector off one end and splice the appropriate signals together. Just try to keep the total length to under 6'. Because the cable you build may be delicate, you may want to build it as a short cable which can fit entirely inside your drive enclosure with the 50 pin connector mounted so that a longer standard 50-to-50 pin cable can connect between the computer and the drive enclosure by plugging into the "translation" cable. Here is the wiring table. Keep in mind that the odd numbers are ground on both the 34 and 50 pin connectors. The new cable should re-route the wires in pairs to help simplify assembly and assure adequate ground. When an entire group of wires can be moved as a set, they are listed together. Signal Name 50 Pin tie to 34 Pin connector connector Pins Pins Side Select (14) 14-15 31-32 Index (20) 20-21 7-8 Ready (22) 22-23 33-34 Drive Select 1 (26) 26-31 9-14 Drive Select 2 (28) Drive Select 3 (30) Drive Select 4 (32) 32-33 5-6 Direction (34) 34-47 17-30 Step (36) Write Data (38) Write Gate (40) Track 0 (42) Write Protect (44) Read Data (46) Again, note that on both connectors the odd numbered pins are ground and even numbered pins are the signals. Do not get the ground and signal reversed. For example, the Index signal line, 20 on the 50-pin connector, connects to pin 8 on the 34-pin connector. 21 connects to 7. When dealing with a group of signals such as 26-31 goes to 9-14, you would have 26->10, 27->9, 28->12, 29->11, 30->14, 31->13. By putting the edge or DIP (but not both ends) connectors "on the wrong side" of the ribbon cable, the cabling system itself will assist in getting the correct alternations. In addition to the above, pins 9 and 10 on the 50 pin connector must be tied together to produce the "double-sided" signal that the Model 16/16B/6000 requires. All other pins on the 34 and 50 pin connector should not be connected to anything. Your cable can look like this: +---+ +-----+ +-----+ ! 5 !--------\ /------! 3 !--------! 3 ! ! 0 !--------\ A miracle/-------! 4 !--------! 4 ! ! !-N/C occurs----------! !--------! ! ! p !------------here-----------! p !--------! p ! ! i !--------/ \-------! i !--------! i ! ! n !-------/ N/C-! n !--------! n ! +---+ +-----+ +-----+ DIP Edge Edge (facing down) (facing up) (facing up) That is all there is to it. Once you have built your cable, and applied power to your drive enclosure, connect the cable to your Model 16/16B/6000 external floppy connector (on the 16B/6000 it is behind the access door and in the lower right corner), and turn on your system. If the drive light comes on and stays on, this usually indicates that the cable is plugged in upside down somewhere (check your pin 1 keying). If the drive light does not light, run diskutil and attempt to format a floppy in that drive. If the drive light does not come on, check the drive select strap on the drive and make sure it is set to the drive number you tried to format. If that is ok, the cable may be at fault. If the drive light does come on but diskutil does not get past cylinder 0, the terminating resistor may not be installed or the cable is incorrectly wired. If diskutil gets all the way through formatting a floppy, and it behaves as though it formatted a double sided disk, you are in business. If you have some programs that are hard coded to expect media in certain drives under XENIX, consider renaming the device names (/dev/fdn, /dev/rfdn, /dev/fdbtn and /dev/rfdbtn) so that you can use 5 1/4" media instead. Be sure to rename all the floppy devs with the same drive number or else you can get into trouble. Although the 5 1/4" drives are 80 track drives, only 77 of the tracks are used under 6000 XENIX, because it still thinks it is talking to a 77-track 8" drive. However, because 6000 XENIX writes the correct number of sectors per track allowed for that transfer rate and motor speed (16 512-byte sectors), the XENIX-usable storage will equal 1.224 meg (((76x2x16)+16)x512 = 1,253,376, which is 24K more than the IBM AT format allows. The full 80 tracks can be utilized, but this requires patching and more operator intervention when performing tars dumps and file-system creation. This and passing data between IBM AT and a 6000 XENIX system on 5 1/4" disks will be discussed in a future issue. One final note: Not all the 5 1/4" disk drives will detect a diskette change as the earlier 8" half-height drives did (most had square lights). (The cost-reduced 8" drives usually had round drive lights and these would only report a disk change if it occurred while the drive light was on.) Because there is no separate signal line available, some 5 1/4" drives simply do not provide that information while others combine it with the READY signal or some other signal. On the drives I used, I found that attempting to use the combined READY and DISK CHANGE caused numerous problems so the above straps do not enable that feature. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - If you have questions about this article, please send email to: Frank Durda IV @ ...decvax!microsoft!trsvax!uhclem ...hal6000!trsvax!uhclem