test-drb June 2011

test-drb@ccmp.vtda.org

141 participants
161 discussions

by tiggerlasv＠aim.com

I've run BA23's with either an RX50 or TK50, and a pair of piggy-backed RD32's. It seemed to work well. I had soldered a pair of 2.2K (?) resistors onto the back of the 4-button panel to force the 2nd drive "ready" and "write enabled" full-time. I may have the details on that particular modification tucked away in my documentation somewhere. I also worked up instructions a while back to construct a ribbon cable to go from an RQDXn controller directly to an RX50 or RX33. I should be able to dig that up as well, if anyone is interested. T

14 years

Is Classiscmp working?

by jhfinedp3k＠compsys.to

I don't seem to be receiving any posts? Does anyone else have the same problem? Jerome Fine

14 years

seeking PC-DOS 2.0

by mcguire＠neurotica.com

Hey folks. I'm looking for floppy images (or actual floppies) of PC-DOS v2.0. Can anyone point me in the right direction? Thanks, -Dave -- Dave McGuire Port Charlotte, FL

14 years

Usenet is officially dead from May 20th ?

by cisin＠xenosoft.com

> "For many years it maintained an almost vegetative life, but on 20 > May, Duke University, Durham (USA), decided to unplug the server host > that kept it alive: Usenet, the online network of discussion groups > formally signed death . It was a precursor to the Internet, but mail, > RSS, and especially Facebook and Twitter have sustituidoel service > they provide." "precursor to the internet"????? If Cern were to shut down their server, would WWW die? -- Grumpy Ol' Fred cisin at xenosoft.com

14 years

SIX Button BA23 Front Panel

by bqt＠softjar.se

On 2011-06-02 07.56, <arcarlini at iee.org> wrote: > Johnny Billquist [bqt at softjar.se] wrote: >> > As far as I know, the BA23 backplane distribution panel can*not* be >> > used for two disk drives. I know there is a DEC note/article >> > about this >> > not working. You need the external distribution board for the >> > RQDX3 to > I used several configs in the DEC lab with 2 RD54s in a BA23 for years > and never hit a problem. (Mind you, I also had a KDA50 in a BA23, so > I'm not saying you should do this at home :-)). It's not an issue with two drives, per se, but an issue with the built in distribution panel. > If there's a note, I'd like to see it sometime ... I'll try to locate it. I know I have it somewhere in paper form, but hopefully it's been scanned somewhere on bitsavers, since all my papers are far from me. On 2011-06-02 07.56, "Rod Smallwood"<rodsmallwood at btconnect.com> wrote: > Two hard drives in a BA23? Like I said above. It's not the question of two drives in the BA23 as such. It is the built-in distribution panel that is the problem. > Provided you don?t want to connect to another BA23 or use a non-DEC disk > controller then a brace of DEC SCSI drives and a flat SCSI cable will do it. SCSI disks have even less to do with it. :-) > I think the drive power cables come direct from the PSU. If so, then you can > rip out the backplane and card guides. The guides can be used to make > storage units for PC cards. You can use the back plane to make a real 'open' > system i.e. one you can get at the pc cards. Yeah, the power cables comes from the PSU, and yes, there was an issue with those on some BA23. But that is something else. And just using the box as a shelf is obviously also not a problem. On Thu, 02 Jun 2011 08:20:11 +0100 Pete Turnbull <pete at dunnington.plus.com> wrote: > On 01/06/2011 18:23, Johnny Billquist wrote: > > >> >> I remember_trying_ to put two hard disks in one machine for quick > >> >> disk-to-disk copies. I have a fuzzy memory that it didn't work for > >> >> me, but I don't remember whacking either drive to the point that they > >> >> didn't work when returned to their former homes. > > > > > > As far as I know, the BA23 backplane distribution panel can *not* be > > > used for two disk drives. I know there is a DEC note/article about this > > > not working. You need the external distribution board for the RQDX3 to > > > use two drives. If you use the BA23 backplane distribution panel with > > > two harddisk drives, you have a high chance of corrupting both disks. > > > (If I remember right, the write gate signal somehow goes to both disks, > > > no matter what, which cause the disk to possibly start writing when the > > > disk is seeking, for example. Very bad.) > Although some manuals do mention that you should only use one hard drive > in a BA23 (eg the Maintenance Manual) I've seen several systems -- > including mine -- do so with no problem. I've never seen a problem with > Write Gate, nor would I expect to. Like all other ST412-type > interfaces, the M9058 distribution card has the same write gate signal > wired to all the 34-pin HDD connectors in parallel. In fact the /only/ > control signals not wired strictly in parallel on those connectors are > some of the drive selects. The M9058 is the RQDXE. Don't anyone ever read what I write, or am I really that bad at expressing myself? I wrote "the BA23 backplane distribution panel". That is *not* the RQDXE. With the RQDXE it works just fine. > What I do know is that the docs say you must draw no more than 7A from > the 12V supply in a BA23, and one RD51 takes 4.5A. So 2 x RD51 would > overload it. I believe that's the only restriction, because putting a > second RD5x in a BA23C expansion box, connected via an RQDXE, was > supported -- and AFAIR the RQDXE doesn't do anything clever with the control or status signals. Yes, the power supply is a separate issue. And yes, there is no issue putting two drives in the same BA23 if you use a RQDXE. However, if you plug in two drives using the built-in backplane distribution panel, you will have a disk crash, which I unfortunately have first hand experience of having to clean up after. The formatting of one, or both drives, will be destroyed, and you will need to reformat the drive to be able to use it again, if reformatting is possible. I never tried that, as I wanted to get as much data as possible off the two drives, and afterwards, the machine got SCSI drives instead of the RD drives, as you might as well upgrade when you were working on it. Johnny

14 years

SMS FWT0100 dual 8" floppy for PDP or LSI-11

by chrise＠pobox.com

I'm investigating some SMS (Scientific Micro Systems) dual 8" floppy units that were built for PDP- and LSI-11 systems. They are model number FWT0100 and, similar to an RX02, have a "formatter" board inside the box with the floppy drives. Then there is a 40-pin ribbon cable that goes to a host controller in the PDP or LSI which can be either a Unibus or a QBus interface. I am wondering if anyone knows if the box+formatter is electrically and protocol compatible with the real RX02... such that you could connect the box to an RX11 or RX211 controller if you do not have the actual SMS host adapter? The documentation for the OEM version of the SMS box (which is out on Bitsavers) talks about the unit being interface and protocol compatible with the RX02 but it is not clear if they are talking about the complete system including their controller in the host or if they are meaning that the interface to the formatter is compatible. The thing has two modes... normal and enhanced and in enhanced mode, there are extra capabilities that the RX02 can not do and I fully expect that you need the SMS controller to operate in that mode... but the normal mode is still a question. I have an RX211 and no real RX02 drives and I now also have one of these SMS boxes so I'm trying to do a little investigation of their compatibility before I just plug them together and see what happens. The RX211 end is pretty well documented. The SMS end... with details of the formatter board... not so much. There is also a FWT1100 version of the SMS box which has a single 8" floppy and an 8" Winchester in it. These work with the same SMS host controller but then for sure run in enhanced mode in order to support the Winchester capabilities. Does anyone have more info or experience with the SMS dual 8" floppy boxes? Chris -- Chris Elmquist

14 years

search for SDI and SMD disks (in europe)

by shadoooo＠gmail.com

Hello. To restore a couple of old machines I'm searching for fixed and/or removable disks. For one machine (a DG Nova 4 upgraded to MV7800) I would need an SMD disk or cartridge drive. For the other machine (a DEC PDP11), I need an SDI disk unit. If anybody has some to sell a reasonable price, please let me know. Thanks in advance Andrea

14 years

Have some Core memory made by Fabri-Tek - trying to find what system this came from.

by ragooman＠gmail.com

I have some Core memory from a guy who worked at Four Phase. They're made by Fabri-Tek and he remembers these being used in some IBM system - the best he can remember. The really cool thing about this is that it's assembled in a way where it folds up. I have some pics at the links below. I'm hoping somebody might know what system this came from. I also have closeup pics of the board, serial, and part numbers too. Then maybe I can find a manual for this. With some luck and some hacking, I can then wire an interface to this for my homebrew PDP-8. http://www.flickr.com/photos/ragooman/5788472143/in/photostream http://www.flickr.com/photos/ragooman/5788471265/in/photostream http://www.flickr.com/photos/ragooman/5789025174/in/photostream http://www.flickr.com/photos/ragooman/5788469637/in/photostream http://www.flickr.com/photos/ragooman/5788469117/in/photostream http://www.flickr.com/photos/ragooman/5789023250/in/photostream =Dan

14 years

SIX Button BA23 Front Panel

by jhfinedp3k＠compsys.to

For those of you who have heard about a mythical SIX BUTTON FRONT PANEL for the BA23, it does exist and actually works. NOTE that the first hard disk drive MUST be set to DS3 and the second hard disk drive MUST be set to DS4. You will almost certainly destroy the format for BOTH hard drives if they are both set the same. A SIX button front panel for a BA23 had been sitting on my bench of spare parts for more than a decade. I finally had an opportunity to use it yesterday for the first time to make a backup copy of an RD51 to a second RD51 Both READ ONLY buttons operate independently and can be turned off and on at any time - as expected, but now verified. There is a simple work around which requires a bit of soldering to a short piece of 10 pin cable, but then the READ ONLY button can't be used very well and is not independent for both drives. I imagine that Tony could add a bit more with a switch that would work much better. If you don't ever use the READ ONLY button, then the simple work around will be sufficient. While I first backed up the RD51 to a TK25 before I installed the SIX button front panel, being able to directly copy (and compare) the two hard disk drives (especially an RD51 which takes under 3 minutes) is much more convenient. This is just to let anyone who is interested that if you are using an RQDXn with a BA23, you actually are able to place two hard drives in the same box. If I am also using the RX50, then I usually run extra long cables out the front of the BA23 and keep the RX50 outside the BA23. If the BA23 backplane is full and you are also using a TK70, then I put both the RX50 and the TK70 inside the BA23 and use the extra long cables to the hard disk drives PLUS I use a spare PC power supply for the hard disk drives so that I don't overload the BA23 power supply. NOTE that my experiments using a BA123 and ESDI Hitachi hard drives which tend to run rather hot and also require their own fans (when I used an external PC power supply), I found that the TK70 MUST use the internal power supply from the BA123. I imagine that the same would apply to the BA23 box for both a TK50 and a TK70. Yes, I occasionally do work with real DEC hardware. Jerome Fine

14 years

Perkin Elmer 7300 Pro System Museum Quality!

by mail.list＠analog-and-digital-solutions.com

Here's one some of you might like. Perkin Elmer 7300 Pro System Museum Quality! http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2738081449 Current bid US $9.99

14 years

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test-drb June 2011