burkett@csd4.milw.wisc.edu (Edward W Burkett) (06/20/89)
I have a Leading Edge Model D with the following installed:
640 K
2400 baud modem
5 1/4 in. floppy
30 meg Seagate HD
DOS 3.2
What I would like to do is add an EXTERNAL 3 1/2 in. drive.
The question is HOW?
1) The LE only has two connectors on the power supply.
1 - for the HD
1 - for the 3 1/4 in floppy
2) The LE has the floppy controller built into the mother board.
Will that controller work or do I need another?
I would like info on what I need to know to do this.
Any help would be appreciated.hollen@zeta.megatek.uucp (Dion Hollenbeck) (06/21/89)
From article <3007@csd4.milw.wisc.edu>, by burkett@csd4.milw.wisc.edu (Edward W Burkett): > I have a Leading Edge Model D with the following installed: > > 640 K > 2400 baud modem > 5 1/4 in. floppy > 30 meg Seagate HD > DOS 3.2 > > What I would like to do is add an EXTERNAL 3 1/2 in. drive. > The question is HOW? > > 1) The LE only has two connectors on the power supply. > 1 - for the HD > 1 - for the 3 1/4 in floppy > > 2) The LE has the floppy controller built into the mother board. > Will that controller work or do I need another? > > I would like info on what I need to know to do this. > Any help would be appreciated. Here are some things you can do, but with some cautions. You can do these IFF: 1) Your power supply has enough wattage to handle an extra drive (has nothing to do with number of connectors). 2) Your BIOS does not disallow flopy drive numbers beyond 0. 3) Your floppy controller does not disallow floppy drive numbers beyond 0. 4) If the model D is an XT style, if you can set the config switches for 2 floppies, or if AT, you cna run setup and it will let you tell it you have 2 floppies. If your internal power supply has enough power for two floppies, merely buy a "Y" connector and draw power for both floppies from the same connector which supplied it to the first one. Make a 5 wire extension for the external one with #12 wire to go out of the cabinet (#12 to ensure not too much power loss through resistance). If your power supply is small or marginal, you can but external floppy cabinets with built in power suppplies to supply the floppy without using the internal power supply. Now that you have power, you need to get the drive control signals out to the external drive. This requires a 34 pin flat cable, similar to the one which currently goes to your first floppy drive. There are two ways to cable two drives. 1) Cable is straight through to both drives and drive A is jumpered as drive select 0 (small jumper block near ribbon cable connector). 2) Cable is twisted (drive select, motor enable) the twisted part going to the A: drive and the straight part going to the B: drive. Both drives are jumpered as drive 1. The preferred way is number 2. The reason is that for some reason, flopy drives do not answer up too well when jumpered as drive 0. By making them both drive 1 and twisting the cable, you have fooled drive A: into answering up to drive select 0. You can find out how to twist the cable by looking inside any standard PC with two floppies. The cable could be made in any manner, but I suggest that the best would be to put the appropriate 34pin connector for your motherboard in the center with the twisted side of the cable being short and going to your internal floppy and the long side snaking out between the case and out to the external drive. Some people may mention about radiated emissions, and I realize that with unshielded ribbon cable, this may be a problem. There are two solutions. 1) Do a whole lot of soldering and create a cable which uses round shielded cable to be the extension for the external drive. 2) Wrap the whole flat cable in several thick layers of aluminum foil. (I suggest this unless you love to solder). Hope this helps. I have done this for a numbe of years. I currently have a PC with 4 drives, 2 internal and 2 external, both working off the same floppy card and an AT with one internal and one external drive on the same card. I'm real pissed off that whoever conceived the AT style setup program decided that you could not be allowed more than 2 floppies. Even though my controller card is set up for 4 drives, the BIOS will not recognize more than 2. BTW, anybody know of a BIOS which will recognize 4 floppies? Dion Hollenbeck (619) 455-5590 x2814 Megatek Corporation, 9645 Scranton Road, San Diego, CA 92121 seismo!s3sun!megatek!hollen ames!scubed/
rlh@fciva.FRANKLIN.COM (Ramon L. Holt) (06/27/89)
In article <3007@csd4.milw.wisc.edu> burkett@csd4.milw.wisc.edu (Edward W Burkett) writes: >I have a Leading Edge Model D with the following installed: > >640 K >2400 baud modem >5 1/4 in. floppy >30 meg Seagate HD >DOS 3.2 > >What I would like to do is add an EXTERNAL 3 1/2 in. drive. >The question is HOW? > >1) The LE only has two connectors on the power supply. > 1 - for the HD > 1 - for the 3 1/4 in floppy ^^^ I'll assume that 3 should be a 5. The 3.5 inch external drive and controller card that I tried to put into one of our LE's came with a power connector that looped into the existing floppy power plug. Such that you plugged power connector that normally goes into the 5 1/4 drive into the 3.5 controller card and the 3.5 controller card had a cord that then plugged into the 5 1/4 drive completing the loop. So both cards and drives are installed. >2) The LE has the floppy controller built into the mother board. > Will that controller work or do I need another? The 3.5 drive I have came with a half length controller card. I did the same thing with the controller card that I did with the power connector. I took the controller ribbon cord that went from the motherboard to the 5 1/4 drive and put it on the 3.5 controller card and took the ribbon cord that came with my 3.5 controller card and plugged that into the 5 1/4 drive, completing the loop. This same hookup works no problems on my AST Premium 286, so that is how I tried it on the LE. But I could never get DOS to boot on the LE this way. It would newer find a drive to boot off of (I think). We tried a couple of different wire combinations like putting in the 5 1/4 ribbon first then the 3.5 controller instead of the other way around. Finally, we gave up and pulled all the stuff off and every other time it booted we would get a memory parity error. And when we tried to run different programs the error would show up and halt the program, so we called our service people (who dred the day they contracted with us to service all our machines, including the LE's). The service people took it to the shop and said it was a controller card problem; swapped that out and brought it back and it still didn't work. So its been in service for about two months now and we have essentially written it off. I hate LE's! My advice would be to get someone who can guarentee their work to do it, or get original LE parts and a good installation manual. -- Ramon L. Holt Franklin Mortgage Capital Corp. (703) 448-3300 7900 Westpark Drive, Suite A-130 uunet!fciva!rlh McLean, Virginia 22102
werner@aecom.yu.edu (Craig Werner) (06/27/89)
In article <587@megatek.UUCP>, hollen@zeta.megatek.uucp (Dion Hollenbeck) writes: > than 2 floppies. Even though my controller card is set up for 4 > drives, the BIOS will not recognize more than 2. BTW, anybody know > of a BIOS which will recognize 4 floppies? > > I'm not sure if this counts. My Wells-American CompuStar is equipped with 2 3.5" and one each of the 5.25" drives, four in all. The config.sys file contains the Wells' supplied DISKETTE.SYS and the PCDOS-supplied DRIVER.SYS. Together, this, along with the hard drive, takes me to drive F. The IBM BIOS mandates that the hard drive be C. However, the aforementioned device drivers seem to let the additional logical drives actually represent additional physical drives, but again, without the CONFIG.SYS entries, those drives are not recognized. Maybe the answer to the question is that a true IBM compatible BIOS that recognizes 4 drives a priori is impossible, but that the little fact doesn't stop people from actually having four drives through more elaborate schemes... -- Craig Werner (future MD/PhD, 4.5 years down, 2.5 to go) werner@aecom.YU.EDU -- Albert Einstein College of Medicine (1935-14E Eastchester Rd., Bronx NY 10461, 212-931-2517) "Well, do you see the spaghetti?"
earl@trsvax.UUCP (06/29/89)
/* ---------- "Re: External 3 1/2" Floppy" ---------- */ In article <587@megatek.UUCP>, hollen@zeta.megatek.uucp (Dion Hollenbeck) writes: > than 2 floppies. Even though my controller card is set up for 4 > drives, the BIOS will not recognize more than 2. BTW, anybody know > of a BIOS which will recognize 4 floppies? > > I'm not sure if this counts. My Wells-American CompuStar is equipped with 2 3.5" and one each of the 5.25" drives, four in all. The config.sys file contains the Wells' supplied DISKETTE.SYS and the PCDOS-supplied DRIVER.SYS. Together, this, along with the hard drive, takes me to drive F. The IBM BIOS mandates that the hard drive be C. However, the aforementioned device drivers seem to let the additional logical drives actually represent additional physical drives, but again, without the CONFIG.SYS entries, those drives are not recognized. Maybe the answer to the question is that a true IBM compatible BIOS that recognizes 4 drives a priori is impossible, but that the little fact doesn't stop people from actually having four drives through more elaborate schemes... -- Craig Werner (future MD/PhD, 4.5 years down, 2.5 to go) werner@aecom.YU.EDU -- Albert Einstein College of Medicine (1935-14E Eastchester Rd., Bronx NY 10461, 212-931-2517) "Well, do you see the spaghetti?" ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Manzanna, has a system where they can let you connect several diskette drives to on machine (3-4-5-6 or more). They normally use a special multiplexor board in series with the FD controller. But on older IBM type machines, they use the external drive cable connector. They have a special "3FIVE.SYS" driver program that allows you to hook up extra drives. For example, on a three floppy and 1 hard disk system with a RAMDISK too; A: and B: are the normal floppies, C: is the hard disk, D: is the ramdisk, and E: becomes the external 3.5" floppy drive. Thus the extra floppy diskette drives go out after the normal diskette drives are used as far as drive names are concerned. If your machine supports it you can use driver.sys and drvparm.sys, etc. and the extra floppy drives would come after your normal system drives. But not everyone's machines support these drivers. *********************************************************************** <This information is provided by an individual and is not nor should be construed as being provided by Radio Shack or Tandy Corp. Radio Shack/Tandy Corp has no obligation to support the information provided in any way. > Earl W. Bollinger @ <trsvax!earl> "You were in the Clone Wars!", said Luke excitedly. "Yes", replied Obi Wan, "I was a DOS programmer. But that was before the dark times, before OS2."