I was the Product Engineer that made the overhead transparency film for HP. The coater that applied the chemistry to the polyester film was making this two to three weeks (336-504 hours) a month. It was converted into 8-1/2” x 11” (or A4 size) sheets and boxed up in the same plant. Same looking box that you displayed in the video, but for transparency’s. Did this for a 3-4 years. Then one day someone from corporate arrived and showed us the ‘new’ ink jet printer from HP. Once I saw the printer print a demo, I realized my product was toast. About six months later we made one last three week run. It was intended to be the final world supply for the life of the printers. We ended up scrapping about 25% of the ‘final’ run two years later. Obviously people were buying the new inkjet printers, with a near infinite color selection (versus 6 colors) and faster, and dropped the 7475’s like a bad transmission. One lesson I learned was technology can change things very very quickly.
Honestly they should've run it concurrent because now in 2023. It's very well needed because you have to use the exact inks or your printer don't work and I have to set my printer to values of 000000 and absolute values of c y and m. Sometimes simplicity is better... thebpen plotters and drawers out now, can only plot one at a time
My grandpa worked for a company that had the giant HP 7580 plotter and growing up I had a massive version of that space shuttle drawing from it on the wall of my bedroom. Seeing it again here really took me back.
Wow! I had one too here in Brazil! It's not the same shuttle, it was a little simpler, but this big A0 paper still in my bedroom wall for some years in 90s. 😊
Try this: Use keycad and save the plot to a file. On the DOS prompt use the mode command to set the baud rate, no parity , one stop bit MODE COM1:9600,N,8,1,P Then do a copy Copy file com1:
I miss my 7475A. I *LOVED* it back in high school. Bought a surplus one so I could have one at home after using it in drafting classes. I even modified a pen to accept a mechanical pencil, and used a Windows 3.0 "handwriting" font to "write" one of my papers onto standard ruled paper. My teacher praised my handwriting, since obviously being written in pencil it *HAD* to be hand-written, right? :-D
That's hilarious! It wouldn't have fooled my teachers, though. I doubt that they'd guess how it was made, but they'd surely know that it wasn't by my hand! :D
@@ocudagledamYeah, but that's just because your handwriting is atrocious and using a plotter wouldn't fool anyone. Don't take this the wrong way; I'm in the same boat. 😉
The plotter is only expecting ASCII characters, (ASCII letters and numbers are only 7 bits), and since you are not sending any characters requiring the 8th bit I'm guessing the National Instruments is trimming the 8th bit on the GPIB side. The fact the KeyCad completely stops responding when accessing the COM port probably means that KeyCad is trying to access COM1 with an incorrect I/O address and/or IRQ. Standard COM1 I/O address is 03F8 IRQ 4. Make sure your COM1 setting in KeyCad reflects your actual COM1 settings. You could also try using the COM2 choice in KeyCad to see if it locks up the same way.
Back then in the 80s and 90s, HP was a technology leader with HP Labs and I *loved* working there. We had leading edge technology with laser printers, inkjet printers, pen plotters, inkjet plotters, scanners, calculators, and computers which were built to last. Bill Hewlett and Dave Packard used 'Management By Walking Around', the 'HP Way' and staff training and development to instil loyalty and enthusiasm. You didn't feel like just a cog in the machine; you knew you were valued, and learnt SO much We had doughnuts for morning tea each day and a subsidised 'canteen' with an onsite chef! Carly Fiorina ruined all that. She spent a fortune buying Compaq for no appreciable result, and tried to shut down ProCurve Networking because it was a viable competitor to Cisco, where she sat on the board. (Can you say 'Conflict of interest'?) She received a severance package of $21 million (plus stock, options etc). If I were incompetent I would simply be sacked. The day she left we kept singing "Ding, Dong, the witch is dead", and there was dancing in the streets of Palo Alto. Sadly, things haven't improved since then. More layoffs, more divestments, and the split into HP Inc and HP Enterprise; neither of which has much to differentiate itself from competitors.
This doesn't deal with the contents of your video, directly, but I just wanted to point out how much I love the attention to detail you put into filming your CRTs. This is probably the best quality video of a CRT screen I've ever seen.
Right from the description: "A minor note about the production of this video, the "footage" of the IBM 5151 monochrome monitor close up is a composite of a real photo with video capture overlayed [I guess he means "overlaid"?]. I couldn't film the me talking about things, the plotter, and the CRT at the same time. So I tried to make the video capture feel more natural by overlaying it on the monitor."
The kind-of-magical thing about this type of plotter, was how how, using only rollers, it could accurately and repeatedly position the paper. If I recall, the mechanism by which that worked, was that the rollers lightly embossed the paper with tiny dents that would then match the rollers as the paper moved back and forth between them, and subtly correct the alignment of the paper back to whatever it was on the previous pass(es).
I think you are correct, and my original comment was wrong. I was remembering a large-format pen plotter in a lab where I once worked. That one left both ends of the paper dangling free and only had the rollers to maintain alignment. They were metal, larger, and visibly patterned. These may just be smooth rubber, in which case they do not emboss the paper.
Thanks for this video, I loved it! It brought back those heady days when I loved working for HP as a Systems Engineer/Trainer on dealer products such as the pen plotters, laser printers, inkjet printers, scanners, calculators and PCs like the HP110, HP150, and the Vectra range. Back then HP products were beautifully engineered, rugged, and reliable. We used an HP7550 plotter to produce all our training slides; it was marginally faster than the 7475A (it only drew one pen at a time), had eight pens, and was sheet-feed, so you could send a whole batch of slides in one go, and not have to hover over the plotter to change pages. The HP7580 CAD plotter (and later HP DraftMaster) was always a major drawcard at computer shows; people would be absolutely fascinated to watch it draw a full A0 CAD drawing from an AutoCAD file.
My uncle is a former engineer and a bit of a tinkerer. Sometime in the late 90s he got his hands on a big floor-standing plotter that fed from a continuous roll, but no software for it, and at that time it was probably harder to find that kind of thing online. So he ended up writing his own software - I believe in Visual Basic - to draw family trees, since he was on a bit of a genealogy kick at the time. He used his own presentation style where you would choose a target person, and their descendants would fan out above them in little leaf shapes, while their ancestors would be in a more rectangular pattern below them kind of like a tree trunk. There was also a patterned border (that style that looks like interlocking S-tetronimos), and he told me the hardest part of the whole project was dealing with the corners. Sometimes I remember it and I think a plotter would be a fun project, though I have no idea what I'd do with one.
Dewd, gotta say, your no bullshit vidoes are amazing, even though I would never use the knowledge, just listening to someone with knowledge and pride being able to both describe accurately and do repairs on a hardware product is amazing.
I worked as a draftsman in the late 90's and used AutoCAD in DOS, sometimes had to do all the printing on A1 plotters and A3 copies. Everything was networked via coax until we upgraded everything later to Windows NT and ethernet. Was a cool time. Everything worked :D All the magic was done in AutoLISP and some custom bat files.
Hi, It look like in KeyCad 6.0 you have the port setup ad 9600 8n1 (12:31), but in kermit you have 9600 7n1 (14:28). Try KeyCad again and set it from 8 bit to 7 bit. Edit: Guess I should have finished watching the video before posting this :P
Glad you got yours up and running I actually gave that Plotter to CuriousMarc in 2021, as it was given to me by the original owner who used it to print out from auto-cad back in the day. I had totally forgotten the peg broke on him haha. One of my favorite pieces of hardware I have ever owned So satisfying to watch in run, even more so than a vinyl cutter or 3d printer I think do to the speed and pen swaps. I actually had my cutting with a drag knife for a while but was a tad unreliable.
7:10 how cool is this, that we’re to the point of practical, at-home replacement part printing :) (Even cooler and more notable is that this is overwhelmingly the result of techie hobbyists and small entrepreneurs who put millions of hours of development into this)
This was my thought. The plotter was cool, I’ve seen them and had created stuff as a kid… But the idea that we are at the point where you just print a thing you need and use it? That’s genuinely mind blowing.
What was fun about these old plotters is that you could sit there and watch the pen move, which left a trace memory in your mind. So there was a sort of an entire story to the finished drawing.
Thanks for the trip down memory lane. My first job out of college (1983) was working for a company that created their own custom CAD system. I was the graphics expert, so I got to play with all the new toys (graphics cards, plotters, digitizers, etc.). The HP 7475 was my favorite plotter to work with.
Hah! Old man! Back in 1983, I was 6! 😂 All joking aside though, slight envy here. I didn't get into computers until the early 90's. Still an interesting time, but I always wondered what it would've been like to have witnessed those wilder early days.
Man I miss this channel. Continuous flashbacks to my high school days of the CAD lab, granted we used equipment that was 6 or 7 years older than this, but still. What a cool throwback to great old gear!
I love seeing it write letters! I also somehow didn't really realize that plotters were ever a thing until just now, so I feel like I have a new rabbit hole to go down!
Watching a plotter plot is really fascinating. Just seeing that paper run back and forth with the pen going left and right jumping all over the place and still drawing perfect circles and letters.
They're fun, you'll usually find them amongst scrap booking supplies with machines from Cricut or Silhouette. While generally intended for cutting vinyl and other thin materials, most have pen attachments. And I can confirm, super fascinating to watch.
Oh my! Decades ago, one of my workplaces was clearing out old computer hardware and someone was ready to just toss this plotter into the dumpster. A little Windex for cleaning, and it worked perfectly, with two full sets of pens. I was a recent tech. graduate, and enjoyed creating images & digital drawings, when everyone else was using color dot matrix or cheap inkjet printers. It was a sad day when the gears got worn out, and the pinch rollers cracked.
That said, still a lot of fun to be had with dot-matrix printers and a roll of chain paper. Which appears to be getting increasingly hard (and expensive) to source... Got a project going, which I should really get back to, to convert our old Star LC-200 printer to a stand-alone text adventure console. I'm sure the Pi Zero would fit inside, and all I need is to convince Frotz to feed a couple of newlines after every response, and retract them again before printing and parsing the next command and its response.
My dad brought one of these home from work, and it was our only color printer until inkjet became a thing. We had this along with a dot matrix printer. This was when having a color printer at home was unheard of.
Wow! Blast from the past. In college the department had a bunch of 7470 plotters, and where I used to work we had a lot of the 7475A plotters for the lab, and a D-size Oki plotter for large drawings. We thought we were in pig heaven.
When I was in high school, I've built myself a laser cutter. It used HPGL as its control language. This way I could cut shapes exported directly from Inkscape.
This really takes me back! I used a 7475A at Uni during a VLSI design course module. It was an RS-232 version attached to a MicroVAX II in a specialist departmental lab. In fact, my dissertation project was to effectively mimic the plotter on a Tektronix graphic terminal. The lecturer was getting fed up with the time VLSI designs took to plot, the cost of replacing the pens and the limited size of the plots. My project was to parse the HPGL output from the design software and translate it into other command codes to send to the (again, RS232) terminal. Even though the design had to be parsed twice (first pass to determine a scale factor to apply so that the design would fit optimally onto the terminal's virtual screen space) it was still a lot quicker than plotting! Also, the terminal had a built-in joypad and functionality that allowed panning, scrolling and zooming of the rendered image. Of course, these days a tablet could do the same thing 1000 times faster for 1/1000th of the cost! 😁
Had one of these plotters at work MANY years ago. When they got rid of it, I 'stole' the camel colored cotton cover and still use it to cover my laser printer to this day.
I have very fond memories of both the 7470 and 7475 plotters, Used them extensively through the 1980s and 1990s with a huge array of HP instruments equipped with HPIB. Also the HP-9836 and HP-85 computers were the go to devices using HP Basic for running equipment test programs. I used to dump out the HPGL into files which I could take across to word and with an import translator (ImageStream) to bring them directly into the reports we were writing as Vector drawings in the Windows Meta File format (wmf). Thus we didn't have to scan the plots and they could be rescaled to any size. My reports were sometimes up to 100 pages were hugely smaller and more portable than my colleagues who would scan in their images as bitmaps or JPEGs. Also for presentations in things like PowerPoint and HTML web versions the vector files were great.
20 years ago I got a dozen of both sizes for $50 each. They are great. The is an HP Journal issue devoted to the tech in these and every detail is amazing including controlling pen lift so that it drops on the paper with zero velocity to keep the pen from being flattened or abused. The tips never get dulled. The paper motion is a thesis and the properties of paper how the grit wheels create a pattern in the paper that is followed every time for perfect alignment. These are a fine example of the detail and innovation in an HP product in the age before Fiorina.
Well that brings back memories... In High School, I took drafting as an elective and we used KeyCAD v6 for our work. (we also used rulers and paper) I remember plotting our drawings from KeyCAD with one of these plotters. It was so fascinating watching it draw our designs in color. This is an excellent look into these machines. Thank you!
I'm gonna have to what if anything is coming out of the serial ports with KeyCAD some time to finally try to get it working with the plotters. I'm so close but it just refuses to take the final step! It seems like a pretty solid entry level program, it looks obvious how to use it and the interface mostly makes sense. So I could see it being pretty good to learn with at that age.
Let me guess: HPGL? We used RoboCAD back in the day, and it would also export the drawings to HPGL. When our school "upgraded" to laser printers, we had a program that would convert the HPGL to Postscript IIRC, so we could print it on the new printers. Still, even though it had "frickin' lasers", it was nowhere near as cool as seeing that little plotter draw out your drawing line by line, using different pens for the different colours. That thing was just... Mesmerising. I mean, there's a reason I bought two of 'em: one for me, one for the hackerspace. 😉
Ah, nevermind, I commented before watching the video and misinterpreted your comment. Didn't realise he had a problem with it. Thought you were just pointing him to "something fun to do to figure out how this stuff works", kind of like sniffing your network packets to figure out how the IRC protocol operates beyond your client's UI.
When pondering the tech from this time period, one thing I think about is how inspiring it was to those that came after. Born in the early 70’s, I’ve been inspired by these kinds of products because of their analog approach to accomplishing their functions. The mechanical>software integration is fairly easy to understand and it enables others the ability to use the same approach for very different functions. In the process extending and expanding the overall utility. I am not sure this same ability to tinker is possible with the tech that has come after. Therefore I think it is important to keep these items in circulation and demonstrated like T² is doing here. And for those in the recycling industry, reuse and education are just as useful as grinding up old tech in to its elemental components.
Our company had 2 or 3 of those. We plotted some complex maps and graphs on these. Wonderful machines. Easy to drive from HP-BASIC (BASIC with a FORTRAN influence) too. Also had an optical site - so could be used to gather data from existing plots.
Many lab instruments had the ability to write directly to a plotter using HP-IB. I had access to a Tektronix 494AP and the plotter was what we used to document problems we saw in the field. We would plot out what the spectrum analyzer "saw" coming down the antenna. It proved to be very useful when documenting interference problems with our UHF radio licenses.
6:30 "Recanning" capacitors is popular in antique radio/TV restoration. Ancient paper based capacitors hollowed out for modern replacements, while maintaining the vintage appearance.
Using the current draw of an electric motor (because the electric current is proportional to the torque) to detect a dead stop or zero point is very common though. It’s cheap and effective, you don’t need an additional position sensor (e.g. led and photo diode) and you can do it with stepper motors. It has been used for a long time (it’s how old 3 1/4 inch disk drives find track 0) and It’s still commonly used today in all kinds of different applications from automatic roller blinds to electric car windows, pointers or “hands” in instrument clusters etc. It’s so common that nearly all microcontrollers for industrial or automotive applications that include motor control functionality support this in hardware. It might sound horrible but it’s a pretty common and safe and effective way to implement this functionality without adding a lot of additional sensor and control infrastructure.
My father has still a 7475A :) He used it back in the day for plotting various scientific data from self-made programs for his work (he was a physicist). I used to play with it too, it was for 10 year old me such a magical machine with the moving pens and paper. Later on I even experimented myself with HP-GL to make drawings of my own :D *ahh memories*
20:58 the long exposure time is a feature for some use cases. It's not too bright, so you can take photos of it for data storage. I have a tektronix scope at work that has shades and connectors for taking polaroid photos of the trace.
I remember there used to be a "print your own greetings card" machine that used a pen plotter. Watching it colour in solid areas by whizzing back and forth was _so_ satisfying to watch.
In about 1985, my brother took me to a computer lab at his university and demonstrated their fancy plotter using that famous space shuttle picture. It was an HP, but I can't tell you which model. It was definitely one where the second axis was done by moving the paper, so it could have been this one. I had that shuttle picture on my wall for years and I think I still have it in a box somewhere
We had 8 of those attached to a VAX8600 back in the day. Nice plotter. When all 8 were in operation it was quite a symphony of sights and sounds. Best not to go in if you were high.
I used HP stuff when I worked at Bell Labs back in the 1980s. Great quality, I miss great hardware like that. I used to automate experiments and plotted out the results at the end.
I used to setup and maintain the serial B, D and E-size plotters in our AutoCAD group (early '90s) and found that they only worked correctly with the unique serial cable wiring specified in the HP manual. Not sure how that would apply to the serial to HPIB conversion but the CAD program configured for the 7475A might be hanging waiting for a handshake that should be jumpered within the connector. We eventually migrated to a Fujitsu B-size 300 dpi laser printer that contained an HPGL interpreter. That instantly obsoleted all the pen plotters.
I have a panasonic VP-6803P with the manual at home here. A 8 pen A3 plotter. A gift from my grandfather. still working perfectly. Love the ascii programming on it. :)
I think the reason it doesn't work from keycad is the commands are slightly different between the serial version of the plotter, and with the hpib version of the plotter. I don't think the serial version of the plotter (that keycad is trying to talk to) needs the address and whatever, and I don't think the NI serial to gpib adds any of that for you automatically. There has to be something different enough in the initialization that it's waiting for and that's why it gets stuck at 0%
@@SeekingTheLoveThatGodMeans7648 Yes, RS-232 is very easy to sniff - just connect the TX line from the computer to both the serial->GPIB converter and also connect it to another computer running a terminal emulator. You can also do it many different ways through software, but nothing beats the simplicity of a couple wires soldered to a custom RS-232 splitter cable and a separate PC (or a scope or logic analyzer that has RS-232 decoding). I would also check the 7475 manual for the differences in the command sets between GPIB and RS-232 versions of the plotter. I had a serial version of the 7475 for a while not that many years ago, and was able to use it with various software without many issues. I cut a little slot between the carousel area and the main area so I could load full sized pens into a hollowed out plotter pen, and used it for directly printing etch resist onto PCB's using a Staedtler pen mounted in a plotter pen shell. I gave it to a friend when I moved, so no longer have it. Prototype PCBs are ridiculously cheap these days, so it's not even worth mucking around etching your own now, but printing the etch resist directly onto the PCB with the plotter worked quite well.
We used this plotter to draw representations of the results of Cardiac Catheterizations. The heart, and connecting vessels, with the coronary arteries were drawn, with the coronary arteries depicting the degree of stenosis in the appropriate places with a narrowing of the drawn artery. Text labeling the artery, and the degree of stenosis also printed. It was of great use to visually show a patient the areas involved and what needed to be fixed. This was maybe around 1987-8?
This brought back some memories. At a company I worked at, we used the 7475 to draw flowcharts to document processes. There was a software product we used but I don’t remember the name of it, that had the flowchart symbols, etc. We would work up the doc and print it on regular paper. When we had the final version we would use the plotter paper. It does work better than standard paper but it was also more expensive. The other thing I forgot about, and yours does it, it would be plotting along and all of a sudden pause, like it was thinking about what it had to do next or just taking a breather. In a way, it was amusing. We had the printer port interface version. IIRC, they also had an HP-IL version plus the ones you mentioned. It was a great unit. I always wanted to get one, but $1700.00 was a lot of money back in the mid 1980’s.. We also had a supplies drawer unit that the plotter sat on. One drawer had the HP plotter paper. The other had pens. Also, as you can imagine, the pens were not cheap either. I don’t think the supply drawer unit was an HP product, but I might be wrong.
Ahh yes SoftKey.. King of the budget houses. I've got almost that exact same package. I kinda liked their Key Home Gourmet package for a basic database designed for and bundled with cooking recipes.
I remember using one of these in my year out job. Waiting around for my plots to print out was kind of mesmerising, bt plotter would often get ten minutes in and either crash or one of the pens would die. It was quite frustrating. I remember the HP IB cables on a GS-MS instrument (with associated computer) I worked with when I was in my 20’s. The computer was on its last legs (and way out of support) so restarting it felt a bit like playing Russian Roulette. Kermit was the first ever network product used. The network switch was a physical box of switches switch someone had built, to connect to a different computer you actually had to go and press buttons.
I have the HP 7475 and the HP 7470 plotters. I use them regularly with my HP test and measurement gear such as the HP 5371A and the HP 70k series spectrum analyzer.
Used one of these at work years ago. I think it was with Lotus 1-2-3 to plot some graphs of data. We would stare at that thing drawing curves and I'd SWEAR the pen was making circles and not just traveling side to side. lol Was just amazing watching it drawing.
Got that exact same model (actually, got two of them; donated one to my local hackerspace), and it's a blast tossing some HPGL over the serial interface indeed. We used to have these at my highschool back in the late early 90's, which is where I first encountered them (and the HPGL graphics "'language", and RoboCAD, my first CAD software). That said, the large pen plotters used at the truck-trailer factory in our city were an entirely different beast altogether. Paper rolls wider than my arms spread wide, so large they came with their own floor stand rather than fitting on a desktop. All powered by IBM RS/6000 workstations with the turny-knobby 90's 3D peripherals used in _serious_ CAD outfits. Would love to get my hands on one of those setups.
Wow. This stuff brings back some ancient memories! If you didn't already know, the weird construction of the HPIB connectors is so that you can stack them to use multiple devices from the same port, so you could plug the HP7475 cable straight into the back of the cable on your older plotter.
I have learned to program these plotters HPGL and load direct from COM port back in the 80s. No drivers needed. It was relatively easy to code it for simple graphics, convert DXF files etc...
I used that HP model for drawing PCB back in the 80’s, using Protel 😅 I used thick paper and taped the PCB to it, and used long acid resistant pens, I had cut a slot out in the cover so the long pen could move freely out of the pen holder 🥲 Sometimes the HPGL it received had char’s missing and the PCB went on the floor 🤪 But that an awesome plotter, wore it down over about a decade, and after that I got a Roland sketchMade that still works to this day 💪
Never leave the paper lever engaged for a long time, especially without a sheet of paper loaded. It will dent the feed rollers. That's what happened to a 2 pen HP plotter I had for a while and I couldn't find new rollers anywhere.
lol... i recently found a box of pens for these from my college years way back. i actually used these things for real once. dot matrix printer takes me back too. nice to see old gear in functional shape still 🙂
I worked for HP after graduating in 1976. We used 9825 desktop calculators for simulation work designing ICs. We used the 7475 to plot the results. In my spare time I wrote a number of games and demos that output to plotters including the 7475. One would take your name (or any string) as input and make a plot that spiraled in from points based on the string as a random number seed. I later did a version for the Raspberry Pi for my local maker space. I also did an artillery game and a lunar lander using the plotter as output.
i had that same model plotter working with keycad a long ass time ago, mine was the RS-232 version, and it was EXTREMELY picky about the cable.. but once i had the right cable and dip-switch settings it ran fantastic.
28:25 of course a colour laser printer could spit out the same page in about 2 seconds and with a lot more than 6 colours... but dang is that satisfying to watch
