a wild Deviant appears!

@@squelchtone 👏😁 yo, bother, good to see you!

I still plan to visit soon! Excited to see this working and everything else!

Never knew you were a vintage telephony fan Deviant

@@joker1859 I am both a fan of the hardware and also a fan of the people there... some of the very best folk in all the land 💚☎️

Yes, that's right. As someone who worked for a IP PBX / call center software company, I totally agree. It has lots of advantages. Not being tied to any physical layer, better monitoring available to users, and having advanced functionality like call re-routing, queues, conference calls, whatnot that would have been prohibitively expensive or downright impossible if someone tried that with PSTN...

Hang on. A lot of those features did, in fact, exist in the PSTN. The reality of the times is that they were selectively marketed because they were not as flexible as people wanted. The irony is that many of the early soft switches simply went to the LSSGR and checked off which items to implement at which points in their development cycles. Meanwhile Nortel and many of the other PSTN switch providers turned their switches into VoIP call servers. One can debate the commercial success of those initiatives, but the PSTN had an enormous feature base that the softswitches could leverage.

@@ctillnc Yes, but it took the newer switches to enable those features. (See: Vertical Service Codes wiki) I remember when they landed in our LATA in SoCal via GTE in the 70s. They seemed like magic at the time.

@@lohphat VSCs were the tip of the iceberg, in terms of what the 5E and DMS-100 implemented. The good stuff was in features for large organizations (governments, F100, etc) and proprietary non-POTS sets.

That is definitely something I’d like to do. It’s a really complex topic so I have to think about the best way to present it. -Sarah

As someone who has built a working step switch, I really hope I can save a small DMS-10 before they’re all gone. Hopefully someday.

Don't suppose they'd be open to a rescue attempt? Where are they located?

At least they didn't choke a ground!

On our old kitchen phone (when I was a kid), we put a swivel coupling on the handset end of the cord, to _prevent_ that kind of tangle after stretching it across the house to the couch. It worked well enough until we got a cordless phone instead. That said, we had it on a comparatively-boring early 90s answering machine phone, which itself replaced a '70s-era Trimline. The old Trimline later got plugged into a splitter behind the cordless phone, and placed on a nearby countertop, so we'd still have a handset near the base whenever _both_ the cordless handsets were across the house somewhere. 🙂 (The cordless had a remote charger too for the second handset, with just a power cable going to it.) I'd forgotten such groovy-looking corkboard phones even existed! And how utterly-appropriate for a late-'70s switch, even if much of the hardware has been upgraded through the 2000s. 😎

I worked on the competitor system EWSD and internally there are E1’s between the dlu (subscriber line frame) and the ltg ( trunk group) and the ltg are connected to the switching network, which is a space-time switching network (all is tdm, not packet switched). An E1 is 31 voice channels, the dlu has a concentration (overbooking) of 8:1 so for 1000 subscriber lines you would need 1000/8=125, 125/31= 4 E1 lines. Each ltg can handle 8 E1’s and a fully equipped exchange can have if I remember 512 ltg’s. But not all E1’s go subscriber dlu’s, you need half the ltg’s to connect to outgoing/incoming trunks too.

That was the switch testing for trans hybrid loss so it could set the gain based on whether you had a loaded line or not. This prevents singing on the line.( I designed the hardware.) This test was supposed to happen while you were picking up the handset. Not the case with handsfree headsets. Also you could set this as a one time occurrence and the switch would remember the settings for future calls. You can also set it manually and totally disable the function. Most central office folks don't want to know anything about the loops that the subscribers are using.

Very interesting! All the calls I ever made on a DMS10 did it. Guess it wasn't on DMS100 as I never noticed it in my DMS100 home calls (on those I only noticed the faint click after dialing an interoffice call). Cincinnati Bell's first DMS10 was the replacement of a Stromberg XY in Union, KY in 1985.

@@ncstewart66 Yea, they could set it once after they determined whether the line was loaded or had bridge taps on it. Then the tones wouldn't be there. Most telco didn't bother. The test was supposed to happen while you were picking up the handset. The hybrid circuit was used to take the 2 wire phone loop to a 4 wire circuit which the switch uses for transmit and receive. Balance is important to properly match the loop impedances and prevent singing and loss. DMS100 never had this feature.

We use wire wrap versablocks, and they've worked out really well. We really only have the horizontal side of the MDF in the cabinet, and then we wire phones directly to the front of those blocks instead of jumpering to another connector block on a vertical side.

You can visit my site at witch.spmh.us/library/ Ignore any SSL certificate warnings. I haven't updated the cert in ages. Maybe I will get around to it tonight :) -Sarah

I think those are DMS-100 tools. Right now we're just reusing the translations that the original telco had, while we try to figure out what they all mean.

@@colinslater195 DMS10 has the same tools. IF you can run a TRAVER that will show you everything you need to know about your translators. The exact call path and ever table the call path takes.

@@212MPH Found it, the DMS-10 mnemonic is TRVR. Looks really handy. This is one of the calls we did in the video. Not too complicated, but we'll see how it looks when we start setting up translations to the other museum switches. LINE BASE LCE 01 1 00 05 6X17 DN 890 0005 OPT 1FR EMR 0 DGT NRML RTP 0 CND TEST ACTV PRFX 1 ASTR N OCTO N DIG 8 TMS 1 N OCTO N DIG 9 PRFX 0 ORIG ACTV PRFX 0 TP 950 N DIG 8 DIG 9 ADDR HNPA TEST ACTV ADDR 903 8900 THGP 890 0 SCRN 0 ORIG ACTV SCRN 0 T800 N TOL N TP ANY N OWT N GEFG DIG 0 DIG 0 DIG 1 TN CURRENT DEST: 8900001 LINE BASE LCE 01 1 00 01 6X17 DN 890 0001 OPT 1FR CWT EMR 0 DGT NRML RTP 0 CND CWID * CALL COMPLETE/DISCONNECTED

We already had these wire wrap versa blocks on hand, and sometimes I'd rather just do the manual work than spend more time tracking down parts. We don't have the big 50 pin butterfly tool.

Don't have the tool, but I predict you will soon get an offer of a donation! Well done!

no. no they were not better.

@@devtrash In my experience, they were. I NEVER had a phone problem until this newfangled nonsense came along.

3: Make a fake reorder tone