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- Опубліковано 14 січ 2019
- How did you connect to a time sharing computer in 1972?
Teardown of the Texas Instruments TI Silent 700 model 745 terminal with acoustic coupler modem.
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I was involved with IC design at Honeywell when I had the pleasure of using one of these terminals. The DEC VAX was the mainframe (betcha can’t use just one!) and everybody connected via phone line. It was Berkeley SPICE 2G, if I recall. Netlists were text only. We managed to design analog ICs using these things. The BEL command was useful if you wanted to get the attention of somebody on the other end of the line. You would hit BEL 3 times and hope that there would be a response, so you could chat about a problem or some other problem.
I designed my own 30 baud FSK modem (to connect to my Radio Shack TRS80 - model 4), so my wife and I could play Colossal Cave (a text adventure game) on the company’s VAX after hours when the kids were in bed. Fun times!
but what is the HERE IS key for?????
@@nikolausluhrs ... It was to identify yourself to the mainframe as in "Here is this terminal". So HERE IS, when pressed, transmits a predefined identification message.
@@sbalogh53 Oh cool, good to know
>@@nikolausluhrs It was a ASCII defined function where one could program a who I am character string in their terminal and upon receiving a who are command character would respond with the stored who I am string. It was originally used in teletype links.
30 baud? Did you mean 300, or really that slow?
^G is still the terminal bell. ^H is still backspace. ^J and ^M are still LF and CR ... Nothing has changed.
plaws0 ASCII forever!
Yup holding Control just subtracts 64 from the ASCII value of whatever letter you're typing and then... bob's your uncle!
^C for "end of text" and ^D for "end transmission" are also ones that I use daily. Kinda nice to have them all labelled on the keys, and I love the spherical profile on the keycaps.
Ben Heck Hacks wait really? That’s really cool, and actually useful to me.
A lot of things that seem quite arbitrary to younger programmers were real, conscious decisions at one point.
This really brings back memories! I worked for TI in the early to mid 1970's, first at the DCD (Digital Circuits Division) in Stafford TX (outside Houston), where I repaired the IC test systems, and then transferred to DSD (Digital Systems Division) in Sunnyvale, CA, where I worked on the mini-computers (960 & 980), and Silent 700 series terminals. The print-heads actually had the driver transistors built into the die, and if I recall correctly, the final transistor was the one that supplied the heat to the paper. Your terminal may still have some life left in it. Try increasing the contrast pot to see if you can get a little more heat to the paper, which may have lost sensitivity to heat over the years. A new roll of paper, or as was mentioned earlier, unroll some paper from the existing roll may also help. As was mentioned below, cleaning the print-head is an excellent idea as well. Use 97% isopropal alcohol and a cotton swab.
Nice..... At age 13 in 1975, my friends father who was an Engineer for Corning glass works, had one to connect to the Laboratory computer. I believe it wast whopping 110 baud. He would dial into the computer (rotary dial phone) and let my friend and I play “Star Trek” on it. It was awesome for the day. I’ll never forget how much trouble we got into when we used the last of his fathers paper playing games. Thanks for reminding me how old I have gotten :-)
It's respectable well-designed old technology. And the documentation is really breathtaking.
Thanks for sharing.
I used to have an old PMG 300 baud modem in a grey metal case. I modified it so the modem could originate or answer depending on a toggle switch on the front panel. I used to download files from a couple of online BBS systems and save the audio to cassette tape. When I played the tape back into the modem a copy of the file would appear on the serial interface. This is how I stored programs for a home made computer I build before I managed to get an old 8" floppy drive. I had an old IBM Selectric typewriter which I tried to convert to a printer by building power drivers for each key. I never did get that beast working. Those were the days.
The manual is absolute gem. I had no idea things were made _this_ clear. Beautiful.
Hi Dave my Dad worked at Lockheed in yhe early 70's; on family day (open house) they brought out the TI silent 700 terminal for games like hangman and (later) LIFE. The thermal paper was very cheap & non-archival(turned brown with heat & sun exposure) but cheaper than huge 132 column line printer paper which they used for satellite test run procedure documentation. Programmers & engineers would check out the TI terminals to take home & remotely dial in & check on diagnostics & tests. Very popular! Led to a boom in Lockheed remote work on Tymshare (brand) systems for FORTRAN work. Also led to my entry into programming!
Nice!
I remember making numerous calls at Lockheed in Sunnyvale. Sometimes at the top secret building, where everything got shut down while I was there... Interesting place.
The oil and gas company I worked for had a few of these for the programmers to check out at night. If you had work on the mainframe that you needed to monitor, you could check out a terminal and use it at home. Made the spouse happy and beat lonely evenings alone in a big bullpen watching a green screen monitor. Not sure how heavy they were, but dragging one across downtown Dallas to catch the bus wasn't a pleasure. Oh yes, don't forget to grab an extra roll of paper. Thanks (?) for the memories!
A number of questions can be answered if you realize that the Silent 700 series was meant to be a portable replacement for an ASR-33 Teletype - you see it has current loop and RS-232 inputs in addition to the modem. Since most people using time shared computers were set up to use Teletypes, the software was optimized accordingly, expecting that the printing terminal kept a record of transactions. Being backward-compatible with the ASR-33 also meant that the standard communications mode would be 110 bits/sec 11 units/character (8 bits, no parity, 1 start, 2 stop), and the high speed would be 300 bits/sec (8 bits, no parity, 1 start, 1 stop). The base model would be upper-case only, and that empty socket may have been where a lower-case character generator ROM would be added, but that's just a guess. I think that the 300 baud, 30 character/second mode was pioneered by GE in their TermiNet 300 series terminals, which used (I kid you not) chain printer mechanisms, and were about as big and heavy as Teletypes. These were not meant to be portable, so the Silent 700 series was also meant to serve that market. GE was also one of the pioneering timeshare companies, so having 30 char/sec printers was a big selling point!
A special Teletype ASR-33 function was the "Here Is" key. On an ASR-33, there was a mechanical drum on which you could program up to 20 characters of ID message, which were transmitted when you hit the "Here Is" key. For most machines, this was not programmed, and it just sent out 20 nul characters (ASCII code 0) (which was convenient for punching leaders on paper tape). Whether TI implemented this on the Silent 700s is outside my knowledge, but I think some terminals just used that key to generate a single nul character, so that may be the case here.
Have you seen the CuriousMarc videos with old Teletype model 19 restoration? Fascinating.
ua-cam.com/users/mverdiell
Check the maintenance manual. There was an Answer Back Mechanism option on the Silent 700, which used a ROM to store the Here Is/Answer Back string.
@@jonathanInLondonUK Yeah, I wrote this before I looked for the manual. See my post about the manual.
@@jonathanInLondonUK The ROM was also used for full-ASCII use, i.e., lower-case letters, and even for an APL (special character set) option.
@@video99couk The models before the 32 and 33 are a little old for my taste, using typebar mechanisms instead of the later type cylinder. I find the cylinder a lot more elegant. You know, from a more civilized time.
The orientation of the blades on the cooling fan show it's not blowing air into the case; it's drawing air through the entire case and blowing it past the motor housing to the outside. Cool gear!
Being able to use one of these, instead of going to the college computer center and waiting in line to use a keypunch, saved literally hours. It was slow compared to modern standards, but using the time sharing system instead of submitting batch jobs via cards was an order of magnitude faster.
As you were flipping through the service manual, at around 20 minutes, you flashed past the print head tension adjuster diagram. I yelled "go back!" At the video, as you could have probably fixed the light printing problem with the thermal head.
Great video.
*_"They don't do theory of operations anymore"_*
You're right, but it's also worth noting that this thing cost about half as much as a brand new car back then. We're talking about $8k-$10k in 2019 dollars
I bet if you bought a similar machine that cost an equivalent amount of money today, the service manual would be really decent.
Yes, it would be really decent. You just wouldn't be allowed to read it unless you were an authorised service technician (who can only be called out if you're up to date with your $5k/year service contract). :( Sad but true, for bits of scientific kit I've seen anyway.
Right to repair is a separate issue IMO, though I think you'd be surprised at how much data you can get about equipment in that price range. The internet is a wonderful thing, even if companies are trying to lock down their own products.
Oh yes they do! My aunt was a executive secretary for 35 years and had long fingernails. Damn woman could type twice as fast as I could without long fingernails. Probably wouldn't work with a modern shallow key with little stroke length. The old keys were really deep and had a long stroke length. When she typed her fingernails were just over the edge of the key. LOL, still don't know how she did it.
Was scrolling to see if someone else said about that.. My fingernails aren't quite as long as hers in the picture but long enough to still require the change in fingertip posture compared to short nails. My nails are usually 5-10mm longer than the fingertip, and when I trim them I go down to about only 1mm extension.
I suppose people who've had short nails their whole life simply don't spontaneously conceive of pressing the flat of the fingertip rather than the round. But any nails that are longer than your fingertip requires to not press with the absolute tip.
It does work fine on laptop keyboards, you just need to change the angle even closer to being parallel to the keys. With short nails you contact all keyboards at almost a right angle, and with deeper travel keyboards you're more 45° with long nails. I think it's actually a more comfortable typing posture anyway, for lots and lots of the stuff.
Just paid attention to how I type with my retro spherical cutout keycaps (very similar to the ones on this terminal).
Mine sit at about 45°, with the round of the fingertip doing most of the contact, and my nail goes just over the top edge of the cutout area of the key.
It's not the absolute tip with the round, the contact area goes about halfway back to the first knuckle. If you look at the side profile of a finger, the contact area starts at the point where the fingertip starts going off at about 45° from the rest of the finger.
I remember my guitar teachers, who were all guys, getting frustrated at my fretboard posture.. but with long nails you cannot use the absolute tip!
But just like with keyboards, using the flatter side of the fingertip works fine (except for some very elaborate fingering work. And then I just trim the required fingers there.)
So it's not uncommon for women in electronics, computing and audio to trim a couple of fingers' nails to make things easier (such as handling small components), like Ms Mad Lemon here on UA-cam evidently sometimes does, but just for typing it's pretty easy to have all of your nails as long as you like.
This is some nice documentation!
Fantastic, what a gorgeous device. Very envious.
In 1971 we used a KSR33 Teletype (Teleprinter) to remote connect via acoustic coupler to a main frame so we could calculate complex inductance formulae at the labs where I worked in the UK. Many of those keys on your machine are marked up like a Teletype. VT = Vertical Tab FF = Form Feed etc. 'Here Is' was the Answer Back mechanism to identify the machine connected to. Loved Acoustic Couplers :)
FWIW, the trick used in V.90 to exceed 33.6kbps wasn't actually particularly sophisticated, but it was clever. Essentially the way it worked was by relying on the accuracy of the DACs installed in end users' line cards in digital telephone exchanges; rather than sending an FSK (or actually, for later standards, QAM) signal, what basically happens is that particular bit patterns (symbols) are assigned voltages, with each symbol being sent as a voltage pulse (Pulse Amplitude Modulation). Your modem negotiates with the line card on the number of different levels it's able to distinguish, which is obviously dependent on line conditions and that's why V.90/92/X2/K56flex modems would connect at a variable rate. The digital data is transmitted, in digital form, to the line card over the network, which requires special equipment rather than a regular modem. In the other direction (upstream), 56k modems actually use 33.6kbps analogue, just like V.34.
I love QAM. It pops up in so many places!
I have a 39 pound 1964 Friden EC-132 _calculator_ that has a CRT and a tag on it with a _FIVE_ digit tech support number!
I smile every time I see that old tag on that old machine!
Used to borrow a portable terminal like this from my high school on weekends. Printing terminals had a feature that after printing the last character on a line, the head would temporarily move to the right a couple of character spaces to reveal the last printed character. If you pressed a key, or the printer started receiving data again, the head would scoot back to it's original position.
You look very much like Lt. Commander Data with his emotion chip going to overdrive. I absolutely love it.
I used one of these in 1986 to debug a Motorola 68000 board I had wire wrapped for a school project (and I have no doubt it was kept in use a lot longer, the owner of the company was rather tight and wasn't about to replace working equipment)
This company built production gear for the automotive industry and the terminal was mainly used for maintenance in the field, and as such it made perfect sense. By then there started to appear "portable" computers that could do terminal emulation but this was cheaper, smaller and lighter than most of those and a lot more rugged, hence perfect for chucking in the back of a car and doing a crazy dash to a car factory where production had stalled.
My father used these for scientific computing well into the 80s, connecting to LANL's Cray-1s and Cray-XMPs. One thing I recall him doing on it was mounting a tape to load one of his programs - submitted the request via batch, and an operator loaded the tape to continue the job.
OMG, I used one of these in college. I think it was connected to a TI-990 minicomputer at the time.
Wow this brings back some memories, particularly the 733 ASR at 17:38 in the video. The 733 had dual cassette drives and my dad had one of these in his workshop at Flinders Uni. I used to use it sometimes at night when I was studying for my BSc. There was a "high speed" 300 baud connection to the DEC 10 in the computing centre. At about the same time I remember playing Adventure on the DEC 10 with an ASR 33 Teletype as the terminal, at the end of a session there was paper everywhere.
Loved the sound of that keyboard
My dad brought one of these home from Bell Labs. Me and my brothers used it to log into the UNIX system at his work to play adventure, hunt the wumpus and Zork. When we used up the paper, we would reroll it the other way around to print from the far side since most printing didn't reach that far. My dad brought home a case of paper, that my mom (intentionally?) ruined by putting it on a radiator. Eventually, my dad built a serial interface to use it as a printer from our Apple II+.
As you are turning that fan it remembers me on my first days as a trainee cleaning a needle printer with compressed air. That damn thing just booted up and started doing things without main. That scared the shit out of me. The air flow generated enough energy through the fan for that whole thing
Micro Switch keyboards were indeed the duck's guts. As noted in a previous comment, the top-of-the-line models used Hall-effect switches. Lesser models used reed switches. All had double-shot molded keycaps. TI had a quite an extensive metals and controls division and made the IC sockets shown in the video, Klixon bimetal thermostats, the clad metal material used in U.S. coins, and perhaps most notably uranium fuel rods!
Enjoy your vids Dave
Sercel is a name I haven't heard in a while! My dad worked as a machinist at syntron when it was bought out by sercel around 2000 sometime. I ended up with two lbs of kester solder, boxes of ohmite wire wound high wattage resistors, boxes of dale/vishay 1/4w resistors, a few bags of axial capacitors and more goodies that my dad grabbed out of their trash and stashed away until I was old enough to know how to use them.
I used to use teletypes/terminals similar to that back in the '80s at college. The 'Here Is' key is part of an answerback system. The remote computer could ask connected terminals to identify themselves periodically to see who was still connected. You would hit the 'Here Is' key and it would send back an identification sequence when pressed. What it sent could often be programmed.
Hi Dave, I worked a lot with this type of machine, the version with two magnetic cassettes. I developed assembler code for the ti tms9900 in I2L technique, one of the first 16bit uCs. The TMS9900 and also I2L are two very intersting subjects, worth of one of your blog viedeos. Besides, in punched card ages, machines like teletype, IBM ball printhed and this TI where always used as operator command input.
"Here is" goes back to the ASR 33 teletypes (even earlier). It requests a programmed sequence of characters from the other end. On the ASR 33 teletypes, there was a drum with tabs which were broken off as Zeros to create the required characters. Here is requested that drum run its characters. It was very much part of the teletype thing.
You're not a real hacker if you haven't held carrier by whistling into your phone.
Sometimes you had to, your modem wouldnt due to some reason.. Required a special kind of two-tone whistle and then you would get handshake.....
@@MrZnarffy captain crunch whistle
When I built a 300 baud modem, I tuned it by whistling one of the tones (which was a certain musical note) according to the kit instructions. Of course it was easier to just dial a modem and adjust the pot until it started working.
Does Silver Bells on a C64 count? :)
Does Silver Bells on a C64 count? :)
Nice video
I was a field service engineer on minicomputer systems in the 70s. We used this series of terminals as system consoles. It was a step up from Teletype model 33 at the time.
I saw lots of print head damage on many units. Also the printed paper output would curl up and fade over time. The glass CRTs eventually replaced these for most applications.
Wow! I remember seeing one of those back when I was around 6 or 7!
The HERE IS key was a mixture between identification and keep-alive mechanism. You could program a fixed response in the terminal, and whenever the HERE IS key was pressed or an ENQ (enquiry) message was received from the remote host, the terminal would send back this message. Heavy duty remote hosts, as I've been told, have been a nightmare to work with, since they often required you to press HERE IS quite frequently or the line was terminated.
I used these in the late 70's and early 80's when I worked with NCR Canada... They were still used to test serial com ports or use as the admin port for quite a while believe it or not... Yes 56K is still alive, the telcomm company I just retired from still has about 200 subs using 56K. These subs usually don't have ADSL or the like....
Nicely luggable (as opposed to portable). Seemed like she was lugging it in the advert! I wonder if that empty socket would be for a prom for the hereis codes. Didn't see any snap-off metal tabs like in the real ttys. I remember using some 300 baud Decwriter terminals in the 80's where the printhead could go faster than 30 CPS. Since a carriage return line feed takes no longer time to receive than any other character, but took a lot longer to reposition the print head. the print speed would "catch up" on the first few characters of the line, before slowing down to the regular 30 cps. Sounded quite different. Thanks for the tour!
Ti silent!
Super video! Still doing cut and paste now for somethings, when using SW is too clumsy or slow.
We picked up one of the previous versions of that terminal form a university for the museum that I work for. It had a UNIX login screen on it and a date stamp of 1986 still visible on the paper.
The "here is" key could be programmed to send an answerback message. This could be sent to the host by pressing the "here is" key, or the host could initiate the transmission of the answer back by sending an .
You could only see the answerback message if you were in half duplex (local echo) mode.
Basically, in the days of terminals that shared time on a mainframe, the computer could ask "who the heck is that?"
The "Here is" key comes from the teletype system. It normally would send some kind of identification to "verify" your identity to the person on the other side of the teletype line. Old electromechanical teletypes used a fixed programmed drum that stored the ID and when you pressed the here is key the data from the drum was send over the line.
Hi Dave, a glimpse at the power supply schematics reminded me of the classic TL494 - probably they have tired to populate boards with handful of parts and decided to spin a chip.
We used these in the Newspaper industry. We had several for AP to talk to a Harris front end editorial system.
I built out my Altar 8800 kit somewhere around 1974. Once it was finished I had no I/O except the front panel (and an AM radio). I really wanted a Teletype model 33 with a paper tape punch and reader, but never could afford one. Still, I learned 8080 assembly language, hand assembled my programs into octal and entered the programs into the RAM one byte at a time on the front panel toggle switches. Then I'd single-step through the program following the logic and reading the results on the front panel LEDs. I was still a junior in college so this gave me a good start on my first job, designing the hardware and software for an arcade video game. It was a grand adventure ... and still is.
Robert Shaver Played some tunes over the radio did you? What a clever sound card!
And cheap too!
Used these terminals in the late 70's and 80's connected to PDP11 and HP1000 computers. They ran at 300baud. The achille's heel was the printhead, which wore out through rubbing on the paper and eventually lost more and more of the heating 'pixel' elements. The paper type had a big effect on the lifetime. I remember using a Hewlett-Packard blue/violet paper which caused rapid failure compared to the official black Texas paper.
Actually, I used one of these when I worked for ITT in the early 80s. They were used as configuration terminals for large PABXs with the added benefit of being able to print the whole configuration and save it as sort of a backup and reference. The downside was that the installation technicians stored the thermal paper printout in a pouch on the inside of the equipment cabinet right next to the power supply, which, in 6 months time made the thermal printout quite illegible ...
Dave, maybe just check your print head flex and connector. Mine did not print either. The aging glue that holds the copper end fingers on the flex had oozed out, and smeared over the contacts and flex when someone took the flex out and back in. It lodged itself right in-between the connector and flex fingers. I cleaned and cleaned with isopropanol, both flex and contacts, until it was gone as seen under the bino. Hurray. Prints again.
"here is" was used by teletypewriter back in the days. from wikipedia:
Some teleprinters had a "Here is" key, which transmitted a fixed sequence of 20 or 22 characters, programmable by breaking tabs off a drum. This sequence could also be transmitted automatically upon receipt of an ENQ (control E) signal, if enabled.[21][22] This was commonly used to identify a station; the operator could press the key to send the station identifier to the other end, or the remote station could trigger its transmission by sending the ENQ character, essentially asking "who are you?"
I love your enthusiasm 🤣 keep it coming your brilliant even if I don't understand what your on about half the time lol
I'll try
That Here Is key sure would have come in handy when playing "Where In The World Is Carmen Sandiego"
Not many of these still in use when that came out, surely? lol.
Oh no! Am I showing my "youth?" 😂
I worked for Compaq in 1982 doing heat dissipation crap while still in college. TI bought the company and I still love Houston.
I remember using one of those in the 1980's to connect to a Data General mini using a 2400 baud modem plugged into the back. You could just type in the old-style AT commands to have it dial and connect. Worked well for accessing the service call system when out repairing things in the field. The thermal paper was fast. This was more of a teletype alternative when it was built.
I used a Model 33 TTY with an acoustic coupler to connect to a timesharing system back in high school in 1970 or so. Good ole Burroughs B5500. A few years later, I worked for Burroughs on the 6700. Fun times. :-) Talk about your wacky terminals... we had some old (even by 1976 standards) crt terminals. Definitely none of your microprocessor trash there! All discrete logic. The screen memory was a delay line, and the character generator was a board full of individual diodes for each bit...
My uncle worked for Microswitch in Freeport, IL. The product was top of the line and much imitated after the patents expired.
hence why we still use the term microswitch...the same as centronics, cannon and XLR...some companies are long gone but their former (c) labels are still used or at least be recognized...:)
The "Here is" key was replaced with the "Anykey"
1:38 The nice thing about old keyboards like this one is that they still have all the characters in the right place, so that shift+number changes the ASCII codes from $31..$39 to $21..$29. None of that modern IBM PC keyboard rubbish!
And look at how they nicely printed the CTRL codes on the keys too. Brilliant!
And for those who don't know, HERE IS sends a string that you could usually program yourself to identify the terminal, and the host computer could send a code to make the terminal sends that string too.
I think the only reason that the modern keyboard layout became the standard, was that when IBM designed the 5150 PC, they wanted the key layout to be similar to their typewriters. Teletypes had this annoying almost-standard layout, which had ( and ) as the shift characters for 8 and 9, rather than the typewriter standard, which had these on the 9 and 0 keys. Also, the " on the 2 key deviated from IBM's typewriters, which had the @ here. So they dedicated a whole 8042 microcontroller in the PC to translating keypresses to codes that lined up better with ASCII. I think the PC may also have been IBM's first ASCII-based machine. Their older terminals (e.g., 3270 series) used a code called EBCDIC, which was completely different.
@@BrightBlueJim Correct on all accounts except the microcontroller in IBM keyboards sends scan codes based on roughly on the positions of the keys. The operating system translates the scan codes to ASCII.
explaination of the HERE IS from an old manual dave.cheney.net/wp-content/uploads/2017/08/Screen-Shot-2017-08-21-at-20.03.33.png
This is just begging to be brought back to working order and hooked into a UNIX system. It should still work, with just a few lines in gettytab. We should be playing zork in no time!
I think a lot of old /bin/sh scripts relied on these keys. I think hell would freeze over before they are removed from unix/linux.
A random search with the might Goog came up with someone that connected one of these to a Raspberry Pi. I think he used it to print Tweets. Not sure. I just glanced at the article.
Michael Lloyd I have done strange and wonderful things with Linux systems and a usb to uart adapter. The serial port is dead nuts simple input for a computer.
and you could telnet to the IBM 360 at the seatle computer museum, as (AFAIK) they got one of these in operating condition....;)
or try the 1401 from curiousMarc ua-cam.com/video/uFQ3sajIdaM/v-deo.html
@@Mostlyharmless1985 Easy to connect to daisywheel and dot matrix printers too! I'm just old enough to have caught the end of everything being simple text sent down a wire.. I still kind of miss it.
Yes you can use WYSIWYG fonts on a printer now... but drivers weren't even really necessary back then were they?
An impact printer would work with any type of ink ribbon.. no DRM ink cartridges.
At least that simplicity means they're still fairly easy to make useful, as you said. I've personally seen one IT department still keep hard copies of some log files, fed by a trusty long roll of printer paper. :)
In college, back in the late 70s, we had both CRT terminals, and teletypes. I preferred using the teletypes as terminals. Remember it was all command line stuff, so older information would scroll off the screen. With a teletype, it was still on the paper, even if it was a couple hundred lines up the sheet.
Awesome! First terminal I used was an Agile A-1 daisy wheel with an external acoustic coupler modem (300 baud). Very cool terminal - letter quality because of the daisy wheel and wide carriage so you could use standard fanfold printer paper. (11"x15"?). Most of the time ya'd use cheap green-bar paper that was the quality of newspaper. Those were the days!
"Here Is" was an answer back for a remote station ASCII (char 05) ENQ... As a teletype replacement it would automatically send a 20 character identifier back to the remote station. The keyboard button allowed the keyboard to send the identifier without the interrogation by a remote system.
Many of those key strokes still work on Unix systems if you hold Ctrl.
Ctrl-H: backspace
Ctrl-J: Line feed, Ctrl-M: Carriage return
Ctrl-L: Form feed
Ctrl-D: End of transmission
Ctrl-I: Horizontal tab
Etc.
I suspect that the old paper is causing the print problems..sometimes old thermal paper does not show print.
Try unwapping a few wraps of paper, then try printing-the inner wraps may work better.
Else, try a roll of thermal fax paper-should work fine.
Also, check the printhead for debris.
Ha ha you are correct sir! Time & slight heat would not only brown the paper, but would desensitize the thermal salts on the paper, rendering it unprintable! 6 months was about the max useful age for the paper, if kept in the original black plastic bags! A new roll of thermal fax paper will indeed work!
Nope, can't use other paper, might void the warranty. It even said so!
F**k the warranty. I would've used what ever brand paper i chose.
I dunno about mobile terminals, but we still had a pair of fan-fold paper TTY (TeleTYpe) terminals for public access at the university I worked at right up till the mid-90's. Learning how to edit a text file on one of these when you didn't have a scene was a real learning experience. But did mean free printing on large-format wide paper - still useful.
You showed your young age on this one Dave. LOL. Learned on PDPs, VAX, IBMs...all terminals. We had teletype and monitor interfaces. Teletype interface was generally used to talk directly to the PDP as a SYSOP as it would spew out data to the printer every once in a while. I miss that old school stuff. Yea, I also did punch cards! LOL
A company I did some work for fairly recently still used dial ups for some of their remote offices. Even though all they needed were pretty simple database queries and such, the terminals functioned comically slow from the perspective of someone having used any type of computer system on a modern connection. Was like going back in time 30 years.
The thermal head probably works fine. What you need is some thermal paper that isn't decades out of date. Paper only had a practical shelf life of a few years even when it was new. You're lucky you got as much as you did.
I used one of these in the 80's to run credit reports. I think I remember typing ATDT meaning "attention terminal dial tone" followed by the number and then would get a prompt for user and pass. You could type ATDP for pulse.
Dave! DO NOT WALK INTO THE LIGHT. come back, we need you.
9:35 of course it has a mains fuse - it's not made by Weller, is it ;-)
I looked up the acronym "FTI" at 6:57 in the internal TI acronym database. It means "Finished Terminal Inventory".
"Here Is" key is operational only if there is an answerback message programmed through set-up. When typed, the key transmits an identification message. The message is displayed in half-duplex.
What's this new fangled rotary dial thang? Back in my day phones were wind up.
The “Here Is” is a throw back to the old telex machine days... it sent a “canned” string of characters that id your terminal, or in the case of the telex machine your telex id
Are the holes near the big ICs for tie-raps, or some rope to fix the ICs (maybe left over from versions before they used hotsnot) ?
I used to use one of those. Man was it heavy!
Dave: take your mind back into 1970's
Me: *ceases to exists*
Funny how we are shifting back to "time sharing" computers aka cloud computing on demand.
Ecclesiastes 1:9-18 New Living Translation (NLT)
9 History merely repeats itself. It has all been done before. Nothing under the sun is truly new. 10 Sometimes people say, “Here is something new!” But actually it is old; nothing is ever truly new. 11 We don’t remember what happened in the past, and in future generations, no one will remember what we are doing now.
www.biblegateway.com/passage/?search=Ecclesiastes+1%3A9-11&version=NLT
Cloud isn't time share, due to the simple fact that two clients can run apps at the same time, even on single core.
Also resource isolation wasn't a possible on time share. You got access to all RAM on your time slot.
It's the same goal but comparing the two is like saying horse carts are the same as cars since both get people around.
It's not reinventing the wheel, it's inventing a new wheel
@@ilyail3 "same time, even on single core" Not physically possible, in modern clouds the "app" runs concurrently with other "apps" by other users and the scheduler makes sure every app by every user get's enough time on the processor by using some scheduling algorithm. (This is also the case with common PC's only difference is that you only have one user to schedule the time for, and things don't happen via internet.) That's exactly what time-sharing means. Only larger difference is that virtualization is heavily used today. So the "app" might think that it runs alone, but if you look one layer downwards the virtual machines are sharing the same resources just like back in the day.
The IC datecode is 78xx, so not 1972.......
My first computer had a 110 baud TTY interface. Ah, those were the days!
Doesn't that keyboard look eerily remiscent of that used on the BBC Micro?
I absolutely loved to type on that keyboard, it was beautifully designed. The WPM and accuracy I could achieve on that thing was mind boggling.
Thing of beauty and a joy forever.
EEVblog Dave, don't confuse Baud rate and Bit rate. Very different animals.
Up to 1200bps baud and bps are the same. However, 2400bps was often erroneously referred to as 2400baud.
@@QlueDuPlessis Not quite right Aadil. You need to remember that Baud, is the symbol repetition rate, in that one baud may present more than one bit. For a telephony circuit, the Baud rate raely gets above 300 baud, but thanks to the use of multiple frequencies, phase shift, and different amplitudes, a much higher bit rate is achieved. The use of QAM (quadrature Amplitude Modulation) is an example. The ultimate bit rate is only limited by the bandwidth available and most importantly, the Signal to Noise Ratio. (SNR) Dave erroneously used the two measures interchangeably early in his presentation.
baud: symbols per second (also non readable like CF,LF,CR....), while bps: bits per second.....
"Here Is" sends a pre-programmed sequence. Radio Teletype operators used it for station identification. Don't know why it's still on a terminal meant to be used over a phone line and not radio.
The Silent 700 series was meant to be a portable replacement for all Teletype model 33 applications, so they wanted to include this. This was an added-cost option, though.
SN98614 is likely used to drive the printer heads, it has some AND logic TTL input and a totem pole power output stage, or rather six of them.
While I don't *use* 56k, I do manage my own internal dial-up internet access server. I even got a fancy rack mount telephone line simulator so I don't need to rely on any external phone line. Super fun to test out dialing in to a modern Linux box with an acoustic coupler modem and a Bell rotary telephone.
30 characters per second? Wow. The closest I came to that was one customer in the early 2000's when I was doing telephone support for a major Australian ISP - he was on a property 30Km from the exchange in the middle of northern WA, and on 16-way Pair Gains. His dialup would only connect at 1200/75 baud. (Needless to say, he ended up moving to a satellite provider)
The 'here is' (And 'who are you') is a hangover from the old Telex style machines, where you would connect to another machine to send a message. you used these to both identify yourself to the called machine, and also request the id of the other machine to make sure you called the righte number.
Ah, the old days, when a Silent 700 was dead sexy compared to the clunking ASR-33 Teletype we usually used to connect to the local educational timesharing service. Them were the days , Acoustic modems the size of breadboxes that took the handset of a ROTARY dialed phone that connected to a Control Data CDC70 with a whole 70 megabytes of storage!
Also, you knew when your computer session was over when the paper ran out...
In early 90's typewriters with parallel ports were common enough. I saw in 2000 that they would be no more and managed to pick a daisy wheel style up on ebay. Still use for sending letters. Nothing beats a physical impression! Yes, did write an RTF file to typewriter driver ... spell check and recording you know!
A vast improvement, it was, over the heavier and slower Model 33 Teletype terminals. It was some time before there was any solution to access from home to industrial or academic computing capabilities, even when the latter became capable of supporting screen interfaces. I began with paper tape and punch cards. These were vastly better.
I used an acoustic coupler as well as standard dB25 serial ports on breakout boxes. 110Baud then 300 Baud over phone lines to University to HeathKit H9 dumb terminal.
"Here is" is like the "SYSREQ" key - if the host needed to be notified there is a unit waiting resources.
Bits and baud are two different things. Baud is a 5 bit code, with a maximum of 32 characters.
This type of terminals can STILL be used on today's computers, if it runs Linux. Most server motherboards still supports BIOS messages over serial, and almost all Linux distribution, along with GNU GRUB2 bootloader, still supports printing boot messages to serial and having interactive login sessions over serial. This means you can hook it to a modern computer that runs Linux with a null modem cable, and use it as if it is still in the 70s.
HERE IS instructs the terminal (if it's programmed to do so) to reply with an identification string. From the ADM-3A instruction manual:
"HERE IS key is operational only if there is an answerback message programmed through setup. When typed, key transmits an indentification message. The message is displayed in half-duplex"
I remember ETX and STX from when i had to interface to an expensive CO2 monitor at work through serial port. Nothing changed since 1972.
I remember logging into what was called the VAX from a state college into a local University in the late 80's. Couldn't tell you the brand. Great fun... lol...