From eric-no-spam-for-me@brouhaha.com Thu Apr 20 17:57:01 PDT 2000 Article: 8225 of alt.sys.pdp10 Sender: eric@ruckus.brouhaha.com From: Eric Smith Newsgroups: alt.sys.pdp10,comp.sys.dec,alt.folklore.computers Subject: light bulbs for DEC front panels X-Disclaimer: Everything I write is false. Organization: Eric Conspiracy Secret Labs X-Eric-Conspiracy: There is no conspiracy. Date: 18 Apr 2000 16:39:21 -0700 Message-ID: Lines: 23 X-Newsreader: Gnus v5.5/Emacs 20.3 NNTP-Posting-Host: ruckus.brouhaha.com X-Trace: 18 Apr 2000 17:36:06 -0800, ruckus.brouhaha.com Path: news3.best.com!news2.best.com!newsfeed.berkeley.edu!enews.sgi.com!news.sgi.com!news.spies.com!ruckus.brouhaha.com Xref: news3.best.com alt.sys.pdp10:8225 comp.sys.dec:58791 alt.folklore.computers:155320 Does anyone have information on light bulbs for DEC front panels circa 1968, in particular for a KA10 panel? The bulbs in question have two metal pins. Some bear the legend "OL-1", and others have two rows of info, "PL10161" on above "1209169". There's temporarily a photo of one, next to a US penny for scale, at http://www.36bit.org/dec/bulb.jpg Would these be the same bulbs used on the PDP-8, PDP-8/I, or PDP-8/e? I'd like to get a manufacturer and part number of a currently available replacement. Or a source of old stock. I've been told that there were also plug-compatible LED lamps in red and green. These obviously must have contained a series current limiting resistor. Any info? Thanks! Eric [If you send a private reply, please demangle my email address in the obvious way.] From shoppa@trailing-edge.com Thu Apr 20 17:57:05 PDT 2000 Article: 8227 of alt.sys.pdp10 Path: news3.best.com!news2.best.com!news.maxwell.syr.edu!feed2.onemain.com!feed1.onemain.com!uunet!ffx.uu.net!spool1.news.uu.net!spool0.news.uu.net!reader2.news.uu.net!not-for-mail Message-ID: <38FCD218.224193D1@trailing-edge.com> Date: Tue, 18 Apr 2000 21:22:32 -0400 From: Tim Shoppa Organization: Trailing Edge Technology X-Mailer: Mozilla 3.03Gold (X11; I; OpenVMS V7.0 DEC 3000 Model 300L) MIME-Version: 1.0 Newsgroups: alt.sys.pdp10,comp.sys.dec,alt.folklore.computers Subject: Re: light bulbs for DEC front panels References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 23 NNTP-Posting-Host: 63.73.218.130 X-Trace: reader2.news.uu.net 956107353 17310 63.73.218.130 Xref: news3.best.com alt.sys.pdp10:8227 comp.sys.dec:58792 alt.folklore.computers:155324 Eric Smith wrote: > > Does anyone have information on light bulbs for DEC front panels > circa 1968, in particular for a KA10 panel? >... > I've been told that there were also plug-compatible LED lamps in red and > green. These obviously must have contained a series current limiting > resistor. Any info? If they're anything like the -8 front panels, there is also a "warming" current through the bulb. The aftermarket LED "upgrades" either had you snip the resistors that kept the prelight current flowing on the front panel drivers, or (more classy) they had divider networks in addition to current limiting to make sure the warming current didn't appreciably light the LED. It was about three years ago I posted an analysis of the divider method to alt.sys.pdp8. I'd be glad to dredge up those calculations here if there is any interest. The divider method is a little more complicated to solder up, but it's easier to go back to real light bulbs if/when you decide to go back to the "completely original" look. Tim. From terry@gate.tmk.com Thu Apr 20 17:58:01 PDT 2000 Article: 8231 of alt.sys.pdp10 Newsgroups: alt.sys.pdp10,comp.sys.dec,alt.folklore.computers Path: news3.best.com!news2.best.com!news.maxwell.syr.edu!newspeer1.nac.net!news.new-york.net!news.spc.edu!not-for-mail From: Terry Kennedy Subject: Re: light bulbs for DEC front panels X-Complaints-To: Email abuse@spc.edu if this posting is inappropriate User-Agent: tin/1.4.2-20000205 ("Possession") (UNIX) (BSD/OS/4.1 (i386)) Nntp-Posting-Host: gate.tmk.com Organization: St. Peter's College, US Message-ID: References: X-Trace: spcuna.spc.edu 956130541 22347 terry [204.141.35.61] Date: Wed, 19 Apr 2000 07:49:01 GMT Xref: news3.best.com alt.sys.pdp10:8231 comp.sys.dec:58798 alt.folklore.computers:155331 In comp.sys.dec Eric Smith wrote: > The bulbs in question have two metal pins. Some bear the legend > "OL-1", and others have two rows of info, "PL10161" on above "1209169". Lucky you - it's still an available part from 800-DIGITAL. P/N 12-09169-00 is a "LAMP; 15V @ .040AMP MAX; .075". It's $2.00 with a 1 day lead time. Terry Kennedy http://www.tmk.com terry@tmk.com Jersey City, NJ USA From eric-no-spam-for-me@brouhaha.com Thu Apr 20 17:58:33 PDT 2000 Article: 8235 of alt.sys.pdp10 Sender: eric@ruckus.brouhaha.com From: Eric Smith Newsgroups: alt.sys.pdp10,comp.sys.dec,alt.folklore.computers Subject: Re: light bulbs for DEC front panels References: X-Disclaimer: Everything I write is false. Organization: Eric Conspiracy Secret Labs X-Eric-Conspiracy: There is no conspiracy. Date: 19 Apr 2000 11:17:33 -0700 Message-ID: Lines: 26 X-Newsreader: Gnus v5.5/Emacs 20.3 NNTP-Posting-Host: ruckus.brouhaha.com X-Trace: 19 Apr 2000 12:14:40 -0800, ruckus.brouhaha.com Path: news3.best.com!news1.best.com!newsfeed.mathworks.com!news.sgi.com!news.spies.com!ruckus.brouhaha.com Xref: news3.best.com alt.sys.pdp10:8235 comp.sys.dec:58816 alt.folklore.computers:155358 Terry Kennedy writes: > Lucky you - it's still an available part from 800-DIGITAL. P/N 12-09169-00 > is a "LAMP; 15V @ .040AMP MAX; .075". It's $2.00 with a 1 day lead time. Thanks! Without the dash after the 12, I didn't realize that the number marked on the lamp was a DEC part number. Based on those specs, it appears that an Oshino OL-6003BP should be a suitable replacement. It's rated about .037A rather than 0.40, but it otherwise matches, including the .075 MSCP. It's rated for 50,000 hours. They're available in the US from Wamco. http://www.oshino.com/ http://www.wamcoinc.com/ Next question: anyone know what drive circuit DEC used? Or at least what voltage they used for the warming current? Since I only have the front panel and not the rest of the computer (pardon me while I break down and cry for a moment...), I need to build my own circuit to drive it. Eventually I plan to have a suitable blue metal box made to bolt the panel onto, and inside put a KA10 emulator. Of course, since the light boards in the front panel don't have any drive electronics, I could just plug in T-1 3/4 LEDs, but I'd prefer to use lamps for some small semblance of authenticity.