Traitor! I was the engineering manager for fax and electronic typewriters for Rank Xerox back in the late 80's early 90's!

In reply to a post by eckiedoo:

And wasn't there something like "Alta Vista"?

Pioneering early search engine developed by Digital Equipment Corporation, first one I used and for years was the default start page on the PCs at work. Could have been great but overtaken by Google. Bought by Yahoo, finally retired in 2013.

https://en.wikipedia.org/wiki/AltaVista

"Vampire Taps"; and you had to be very careful and pedantic, to ensure that it was done properly. (A simpler version is available for making "live" connections to water pipes.)

Also the "Thick Ethernet" had markings about every 2.5 Metres; and you had to make sure that this was the minimum distance between adjacent taps, otherwise there could be standing/reflected wave problems.

I have fitted many of them; but one stands out, as it fed a particularly critical department.

As a result I had to climb a 25 foot, 4 part extension ladder, to reach the location up in the roof structure, carrying the required parts tucked in to my shirt and pockets.

No platforms etc, teetering and manoeuvring at the top of a shoogly (shaky and "buckling") ladder, two Works Engineering staff trying to steady it at the bottom; and because of it being in a "corridor", unable to get the ladder over to the best angle from vertical.

And being up in the roof - extremely warm.

The first operation was to fit a clamp, an essential part of the Vampire Tap Unit, on to the cable, making sure that all four Allen screws were properly bedded down, not trapping any insulation.

If even this "simple" operation was not done properly, the actual pointed tap, which was later screwed in to the clamp, would not fully penetrate the coax cable and reach the centre conductor.

In that aspect, all dimensions affecting the tap penetration were critical.

The next operation was to drill in to the cable, via the tap threaded hole in that clamp; but with a special, hand operated drill.

Basically a short drill bit about 1/4 inch long (6mm) mounted in a handle.

Generally the clamp and tap hole was on the far side of the cable, so one had to reach beyond that point, then bring the drill bit back towards oneself; but in that hole.

Then twist the drill etc anti-clockwise as viewed, pulling it towards oneself, hand and wrist bent at right-angles, to aid the penetration of the cable - generally the opposite direction to conventional drilling.

Making sure that the hole was cleared of swarf, the tap was fitted in to the clamp, again having to be fully screwed in to ensure the proper penetration to the inner conductor.

Mount the main body of the tap unit to the clamp, then strapping it in this case to the inverted L-shaped roof beam.

Connect up the drop cable, in this case a particularly long and heavy one; and strapping it to the beam at least twice, using three nylon straps to each strap group.

What would be the centre strap of each group was tightened on the beam alone first, placing the cable over/outside/not trapped by this strap, followed by the other two enclosing the drop cable, either side and as close to the centre strap as possible, thus forming a shallow "omega" in the cable giving extremely good retention.

Additionally, to help ensure good connections at the main tap unit, ensuring that the immediate part of the cable had some slack which was absorbed as some compression in to the tap unit.

This was done by ensuring that the leading edge of the shroud reached the main end face of the tap unit, tightening the two restraining straps in the first group, then pulling the cable connector back slightly, to offer up to and enter the corresponding connector on the tap unit, thus compressed or "forced in".

The second (and occasionally more) group of ties helped ensure that any subsequent minor movements of the drop cable would not affect the tap unit connections.

Wearily and warily descend the ladder, to connect the lower end of the drop cable to the Server, with its onward connections to the PCs or terminals; and ensuring that all were working correctly.

Make my way back about 1/3 mile (600 Metres), to resume my program writing, systems analyses, general trouble-shooting et al.

Also many a caper with Thin Ethernet and Appletalk.

==================

On another occasion when we had taken over another building, the local management insisted on employing a networking company to make 5 similar connections to a new, thick Ethernet cable, at about 7 foot (2.2 metres) above floor level etc and easily accessed,

I subsequently had to re-do four of them, basically the clamps had not been properly mounted, showing slack in the Allen screws, trapping etc, so all the rest of the operation suffered.

Edited by deleted (Thu 04-Sep-14 12:00:52)

Methinks that J Arthur Rank and also the Xerox pioneer, Charles Carlson, were not even "twinkles in their fathers's eyes", when Muirhead was working!

https://en.wikipedia.org/wiki/Alexander_Muirhead

Edited by deleted (Thu 04-Sep-14 14:15:41)

I think I have a Muirhead signal generator in my shed!

"Thinwire" Ethernet and LocalTalk/AppleTalk.

More technical this time; and no ladders!

I was called late one afternoon, to a newly-arisen problem, in a location where the user, Jim, had an early MAC connected by AppleTalk (AT) to a Kinetics FastPath, KFP, which altered the protocols appropriately from AT to Ethernet for outgoing packets and the other way round for incoming packets.

Jim was accustomed to sending Print Files from his MAC to an Ethernet printer, a short distance away; and them taking about 4 to 5 minutes to actually physically print (long document, many pages).

Suddenly that day or afternoon, this job was taking over 4 hours; but all other print jobs and the PC/Terminal users on Ethernet were not encountering any problems, to them every thing was normal.

I had a quick look around, restarting the KFP, printer etc, not spotting anything, so off home.

The following morning having run my "Dawn Patrol" procedures on our 3 large DEC VAX computers, which included amongst other things, sending a Test Signal to equipment in a remote building about 3/4 mile away (1 Kilometre) over BT Kilostream and getting a reply confirming that generally all was well, I returned to Jim's location and that printer problem.

I had a more thorough look around, still not seeing anything untoward.

Then talking to Jim some distance away from his desk, I spotted that another desk had been moved; and that the ThinWire Ethernet network in the immediate vicinity had been interfered with, a single longish co-ax cable of uncertain origin, therefore impedance, had been added to the vertical of the "T" piece connector, which normally would have been connected directly in to the equipment on that moved desk, this "extension" being substituted to reach the desk's new position.

I immediately removed the extension from the T piece, followed by removing it from the desk equipment.

PROBLEM SOLVED!

The printer immediately speeded up on Jim's job, returning to its customary 4 minutes approximately.

The other user started to protest that he had lost "2 hours work" because of my rapid corrective action - he had only been in about 1/2 an hour.

"Did you do any 'SAVEs' during that work - "No".

He threatened to report me to "Senior Management" etc; and ranted on in similar vein - until I pointed out to him that this would make HIM open to "Immediate Dismissal for Unauthorised interference etc of any of the Networks" (Staff Conditions of Employment) as he would have to have confessed to having done so.

I was the only person directly authorised to extend and/or modify any of the networks, over several buildings and dispersed sites, except if any other person was working to my instructions.

Plus his lack of professionalism and expertise by not having carried out any "SAVEs" over an extended period.

My recommendation was that a "SAVE" should be done about every 10 minutes, even if the change was a single key-stroke; and if there were any significantly larger changes such as merging other files, then the saving should be done immediately afterwards.

Also that users should occasionally create their own back-up copy of the file/s with appropriate changes to the names, slightly difficult under the old 8.3 naming regime.

Whilst he was calming down at the possible prospect of Instant Dismissal, I organised the proper extension, using two cables, with a T Piece into his equipment; and making the necessary changes at the original T Piece.
-------------------------
The Design Engineers involved had little practical experience of networking, transmission lines, reflections etc, so were not immediately aware of possible effects of using the wrong type of co-ax cable, dummy loads etc, with the Ethernet impedance being 50 ohms, whilst so much other co-ax being about 75 ohms, with little visual difference.

The purchase of an early TDR, Time Domain Reflectometer or my Pocket Radar Set, made a big difference to maintaining the Ethernet networks, helping by locating any reflection, the approximate distance to most faults; and the testing of any new cabling both whilst being produced and assembled.

Later I would place the new section in its intended working location, do some tests with the TDR, then do a quick swap, the latter could interrupt the run of Ethernet for up to about 15 seconds before causing observable problems to the users.

Bigger changes particular any involving cutting a long run and re-terminating had to be done in "quiet time". If the long run was readily accessible, then the previous method was used.

Experimentally I tested Thinwire Ethernet out to about 2,000 feet (600 Metres) using reels of cable, for an urgent extension of about 1500 feet (450 Metres).

That extension worked for many years, until abandoned due to the building changing hands.

Oh yes, I was aware of it's history, the earlier versions were horrendous, but the principle was there and they worked !!!

We used ours for Up to Confidential material, maps, photos etc. Nothing above Confidential was ever sent via MuFax and I never understood why because it went through the exact same process as all our other kit. So there must have been a flaw somewhere or perceived flaw somewhere in the kit!
Never did get to the bottom of it!

Anyone remember using Gopher
Edit to correctly call it the Gopher protocol !!!
Makes it easier to lookup on google if it rings a bell with you

Edited by TrevorSP (Wed 10-Sep-14 17:22:14)

Oh oh oh, and CiX internet Exchange too, that was my first "social" line into the house
You could send emails using AMEOL, and the rest was just a BB Forum !!!

Edit to add, they still exist at http://www.cixonline.com/
Edit AGAIN, just to add they have JUST been sold on......

Edited by TrevorSP (Wed 10-Sep-14 20:16:55)

Ketchup! http://forums.thinkbroadband.com/general/t/4354455-2...