The power requirements are the same, i.e. the DC supplies work for any of them, though not all drives require the negative supply, but the connectors for AC are often different for DS drives than for SS drives. Siemens FD800-2's are notable exceptions. Dick ----- Original Message ----- From: "Lawrence LeMay" <lemay(a)cs.umn.edu> To: <classiccmp(a)classiccmp.org> Sent: Thursday, June 28, 2001 7:54 PM Subject: Re: WTB: 8" floppy

I'm not sure I go along with that. While it's advisable to check requirements before hooking up any device, I've got to say I've never seen an 8" drive that used the "conventional" DC supply connector for 8" drives, as defined by the Shugart folks, et al back in the '70's, that wouldn't work on precisely the same power configuration, using +24, +5, and -5 with the associated returns. While there were some drives that would tolerate -12 in place of the -5 if you jumpered them approproately, I've not seen any that would be damaged if you overlooked that detail and simply hooked up -5. Moreover, the majority of drives available by the mid-80's, admittedly late in the 8" drive's market life, didn't even require the negative voltage. Oddly enough, even the later 8" DC-powered drives from Shugart, Tandon, and others, used that same connector for their DC supplies, though several of them immediately regulated the +24 down to +12. NEC's DC-powered FD1165's, by the way, were a noteable exception in that they used the same little connector for power as the 3-1/2" drives use. That was why I gave away the ones that came into my possession. I don't know what their DC power requirements were. Dick ----- Original Message ----- From: "Fred Cisin (XenoSoft)" <cisin(a)xenosoft.com> To: <classiccmp(a)classiccmp.org> Sent: Friday, June 29, 2001 10:16 AM Subject: Re: WTB: 8" floppy

On Fri, 29 Jun 2001, Tony Duell wrote: Another similar nasty: I have a 3.25" drive that uses the same connector as a 3.5" drive, except that the +5 and +12 pins are reversed! Fortunately, the 3" drives that I have use the same connector and pinout as 5.25". (which seems to be standardized) -- Grumpy Ol' Fred cisin(a)xenosoft.com

--- Richard Erlacher <edick(a)idcomm.com> wrote: I think I got one of those at Dayton a few years back (> 8)... It was sold to me as a SCSI enclosure, but a moment's inspection once I got home revealed that to be false. I might have the board around; I know I have the Davong enclosure somewhere - used it for a while with an ACB-4000 on my Amiga. -ethan ===== Visit "The Seventh Continent" http://penguincentral.com/penguincentral.html __________________________________________________ Do You Yahoo!? Get personalized email addresses from Yahoo! Mail http://personal.mail.yahoo.com/

I had thought someone actually wanted a DSDD 8 inch drive. NEC 1165's available....

The thing that might be interesting with NEC1165's would be to compare them to 3-1/2" drives. Though I'm not certain about it, the power might be compatible. If not, it just might be a mite risky to package the two drive types together since the power connectors are the same. These NEC people made a number of moves of that sort in the early '80's. They built a number of PC clones that were "almost" clones ... and you know where that led them ... Dick ----- Original Message ----- From: "Jeff Hellige" <jhellige(a)earthlink.net> To: <classiccmp(a)classiccmp.org> Sent: Sunday, July 01, 2001 9:55 AM Subject: Re: WTB: 8" floppy

I wasn't specifically referring to a model, but to the general run of NEC PC-clones of the early-mid '80's. It seems to me that their story, overall, was that they were intentionally not compatible with the PC, thereby forcing the end-user to buy the software that NEC had to offer. That's what killed them. Later models were, presumably, closer to the "compatibility" mark, hence more generally useable. I never owned/used one of these jewels, but there was considerable chatter about them back then. Dick ----- Original Message ----- From: "Iggy Drougge" <optimus(a)canit.se> To: "Richard Erlacher" <classiccmp(a)classiccmp.org> Sent: Sunday, July 01, 2001 7:30 PM Subject: Re: WTB: 8" floppy

What is the difference between a: 1. DECstation 78 2. DEC WT-78 ("WT" apparently standing for "Word Terminal") 3. DEC VT-78 ("VT" apparently standing for "Video Terminal") -W

The connector definitions from the '70's, before they thought up the LSI board or even the intermediate board that actually didn't require the Vee supply, however, relied on the presence of that negative bias for the read amp's. If you plug the DC supply compatible with the ORIGINAL version of that SA80x connector into any drive that uses it, it will work, though the Vee and possibly the 24-volt supply as well, may be redundant. It's quite true that supplies concocted with the intention of eliminating the redundant supplies won't work with the older drives. However, it's unlikely they'll hurt the drives, though the drives won't work properly. Dick ----- Original Message ----- From: "Tony Duell" <ard(a)p850ug1.demon.co.uk> To: <classiccmp(a)classiccmp.org> Sent: Friday, June 29, 2001 3:20 PM Subject: Re: WTB: 8" floppy I've supply +24, would hooked admittedly voltage. them the for

Though I've heard of them, I've never seen an 8" drive that operated from the Vcc supply alone, nor have I seen any printed allusion to them. Back in the days when the 8" drive was in full usage, there were few drives available that didn't use the three available supplies. In the years when smaller drives were becoming popular, manufacturers of 8" drives figured out a few things that might be impacting their reduced 8" drive sales. These included the use of several supply voltage requirements, but that was partially dealt with by using single-supply amplifiers, and the noise of the AC motors, which was dealt with by using DC motors. However, the sheer mass of an 8" drive mandated a cost that was easily beaten in the marketplace by the smaller drives, and, no matter how well the 8" drives did with reduction of power supply demands and in noise, once the smaller drives were able to produce the same capacity, not to mention that the evolution of the hard drives of small form factors were able to offset the capacity demand somewhat, the fate of the 8" drive was sealed, even if its capacity could be doubled or tripled, since the combination of floppy and hard disks was now a reality, and large capacity was no longer of such large interest. 8" drives with which I've had contact, with a VERY few very old exceptions, notably PerSci, have always used the Shugart-defined 6-pin connector with which we all became familiar if we used 8" drives in the '70's. If the drive required a supply, it was normally provided by the PSU that one commonly associated with 8" drive pacakges, e.g. the PowerOne CP206 and others of that ilk. If a drive didn't need the Vee supply, it didn't matter that it was there. If it did need that supply and your particular supply didn't provide the correct voltage, an on-board regulator on the drive could be installed to handle that if it wasn't already there. Moreover, many supplies were adjustable, either by tweaking a pot or by changing a resistor (since they nearly all used the uA/LM 723 regulator, which worked in that way. If you simply hooked up a supply to a drive without first verifying that the Vee supply was properly handled, one might say you got what you deserved, however. Aside from the Vee issue, which only occurred in a very few cases wherein there was no regulator on the drive AND the supply was incorrectly set up, there was little likelihood of damage to the drive or supply. The drive was unlikely to work if Vee was -12 volts, however, if the drive was set up to use -5. Permanent damage to the drive was unlikely however, since the devices involved were of a type normally used with a bipolar 15-volt supply. While the biasing necessary to make these work at bipolar 5 volts wouldn't work if the two supplies were unequal, serious or permanent damage was unlikely. Dick ----- Original Message ----- From: "Tony Duell" <ard(a)p850ug1.demon.co.uk> To: <classiccmp(a)classiccmp.org> Sent: Saturday, June 30, 2001 12:27 PM Subject: Re: WTB: 8" floppy board If possibly

I've got your drives! Want an EISA box with those? Jeff Hellige wrote: