I Thought It Would Be Easy… It Wasn’t

This TI-810 Printer was very kindly donated by BoxcarJim and it was in such unbelievably good shape, I thought it would be a walk in the park to bring back up. But, as I’m sure most of you are keenly aware, printers always throw curve balls. We had all sorts of failures to overcome and then the nightmare of cabling. In my defense on the cabling issue, I had the wrong manual, which made life way more difficult. We got there in the end though, and bent this thing to our will!

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Intro Music adapted from: Artist:
The Runaway Five Title:

Thanks for watching!

Chapters
0:00 Something is missing
1:10 Filling the void
3:15 Surely it just works, right?
4:06 Disassembly, cleaning and paint
5:59 A look at the PCBs
8:02 Troubleshooting the Error light
10:57 A battle with the encoder
15:03 Testing and more problems?!
19:17 The final boss, hooking it up to the Centurion
23:35 Cut! Let’s try that again!
27:12 Relaxed bunny!

[donnieweston]

Your enthusiasm on getting this old tech working is why I continue to follow your channel.

[paulscarlett]

RS-232 standard -- the most non-standard ever!
Only (?) TI used that reverse channel. I spent a 3 hour WTF session attempting to determine the same issue early in my career, so I sorta knew where you were going. Nice to see it working!

[juliannicholls]

I used to use one of those TI 810 printers 40 years ago in my first job. It was a beast. I recognised it immediately, before you even showed it close up.

I also remember the joy of creating a serial cable that satisfies both ends to go from the serial port on a computer (pre PC compatible, CP/M usually) to a printer, often without a manual for the printer, and sometimes without a technical manual for the computer either.

[uraniun]

Printers are just disobedient little robots, but it was a lot of fun watching you get this one to behave.

[Ben-says-you-are-AWESOME]

There's something very satisfying about the sound of a dot matrix printer whirring away.

[kromaine]

FYI - The Centurion printer type PRTQ is the nane of tbe Centurion print spooler program. The print spooler lets you send a print job to the PRTQ at full system speed and not be limited to the slow printer speed. Once the print spooler program receives the print job the printer starts printing the job, and the system user to do other jobs as the spooler prints the last job. In the case of this CPU5 system OPSYS gen. PRT0 is setup with the TI-810 printer driver.

[yohannwilkerson]

Ahhh... I love the sound of a busy dot-matrix printer.

[thewise]

I never thought I'd witness someone getting so excited about a printer light. Your enthusiasm is infectious.

[haraldtscherne]

Hi David, great work again! I used to repair similar printers for Digital Equipment in the 80s and immediately thought of an encoder problem when the printhead did not move to its left margin at power up. A word of advice: if you ever come across a dot matrix printer from DEC, do NOT remove the encoder PCB from the carriage motor unless you have the manual describing the correct encoder adjustment procedure. On those printers, you must usually power the motor with some 5V or so, hook up your scope to the photo sensors, and then physically move the block housing the photo sensors only fractions of millimeters to produce the correctly timed pulses. You need a scope and very calm hands, it's a really fiddly task.

[UpLateGeek]

Honestly, I'm surprised the corrosion wasn't more of an issue. The fact that it only caused fatal damage to a socket and flex PCB is a testament to how well those boards were made. Great work getting it going again!

[MarcelHuguenin]

The TI810 was the very first dot matrix printer I worked with in 1979. I hooked the Centronics interface to our own Commodore IEEE to Centronics Parallel interface box and produced lots of output on it. I do remember how loud it was. Great to see it turn up at your place and restoring it! I always found it an awesome printer.

[antonnym]

Nice job! A trick we used to do with old ribbons on printers to refresh them was to squirt a little bit of WD40 on them. This redistributes ink from the edges of the ribbon which never see any action, down to the "battle zone", so to speak where the pins contact the ribbon, and it extends the useful life of the ribbon. We used this as a cost-saving measure because me and my friends couldn't afford ribbons that often. All good wishes.

[alexh]

David the sights and sounds of that printer brought back a lot of memories! Our family travel agency had an early install of United Airlines "Apollo" reservation terminals. The set up included 2 of those Texas Instruments printers, one loaded with triplicate carbon paper for invoices, and another with plain paper. The printer/computer room had a sliding glass door to drown out the sound of the TI printers, ticket printer and the network box with its fans. Also the smell of the paper/print and the heat was also pretty unique lol..thanks for the awesome content!

[markwerley]

Early in my career I spent many many hours listening to a TI-810 hammering out reams of green-bar paper. In my application for the job they stated that I had to be able to lift 45 pounds, an oddly specific number, and also the weight of one box of green-bar paper.

[ManunKanava]

24:00 Please no, my eyes hurt. That was a flashbang on my eyes.

[JT-kzkq]

RS232 IMO is the best example of a non-standard 'standard' interface. When I was dealing with RS232 connections back in the 1970/80's I used to first use two straight-through ribbon cables with a female/male connector on each end connected via a RS232 breakout box. Then I would sort out the required pin connections via the box and then when it's working I would make up a proper cable with the required pin connections. Back in the day some terminals required straight through, some required x-over for pins 2 and 3 - and then there's handshaking! There was one particular computer I worked with which required a high on a certain pin to work but didn't set any other pin high until it saw that particular pin high. Nightmare as you couldn't just connect control pins together in the plug to get it to work. There was this one serial printer that a customer wanted to use that required a high on a pin for it to become ready and before it would raise any other pin high. Needles to say that getting that printer to work with that computer was not easy. Ah the bad-old good-old

[scottyb]

Watching that thing print out the list of patreon members and supporters would be a great finish to an episode.

[pquodling]

Finishes with a listing that has code fixes dated 1977. 47 years ago... Love it.

Back about then, I was a Field Service Tech for DEC in a remote site - everything from PDP8 to 10s, LA-series printers and old teletypes - when my boss told me I didn't need an oscilloscope to fix things anymore, I moved into SOftware - I bought one of their excess inventory Tek475 scopes for $50, which is still in my lab and still working.

[garthhowe]

This brought back memories. In the late 80's I worked with all sorts of dot matrix line (?) printers connected to mainframes. The sound is like music to my ears.

[lmkan]

Living in The Netherlands and owner of 23 pinball machines I sure loved your 2 in the background. Good to hear your brother will take good care of it (mayby them soon). Understandably you made a wise decision from your hobby's point of view. Love it. Keep up the good work! Cheers from Amsterdam