(Crappy ascii art trigger warning) # Day zero Behold, I got a box! .-------------------' .------------------./ | | ______________ | | | |From ebay with| | | | |love | | | | `````````````` | | | | | | | | | |/ .`------------------' Or, here is an actual... (IMG) photograph ... rather than a textual representation. You see, a few days earlier, I had ordered a HoneyWell terminal from ebay. I am not particularly in the habbit of buying a ton of stuff from ebay, but this is a HoneyWell terminal!! The reason for all of my excitement is that I am rather fond of the Honeywell (and earlier General Electric) family of mainframes this thing was used with, namely the DPS series, and the GCOS (or earlier, in the GE days, GECOS) operating system that ran on them. (they also ran multics) - and until recently anyway (because the guy is selling a bunch of them) you NEVER saw these- or any type of DPS-related stuff on the bays of Eeeeh... I do remember once upon a time a tape system being sold, for looooooots of dollars, but that's about it. So cool. I excitingly grab a sharp object and cut the box open, and reveal: ________ /_////__/| || | | | ||____|_|/ /###### #/ --------` (IMG) ... It's contents! Alright awesome! Just look at it! It's relatively clean, but still has a nice patina. It even has an old printout with random names labeled "buyer names" still stuck to the side. What tales could it tell? But more importantly, will it work?! The ebay auction said it did, but I'm not sure if I trust just powering on this thing and frying it without having a look at the innards first, and at least poking around with a multi-meter for obvious shorts.... *pokes around the terminal to see how it might open*... but ooh... what's this?! It's modular! It appears the main circuit board just slides out as one solid module, encased in plastic: .---------. |\ /| | | | | |=========| |________\| ________. |\ \ \ \--------- \|_===__==_| (IMG) Alright, you get the idea,.. here's the picture. With the board out, I could peek inside and figure out that the cover was held in place by 2 screws, once those were out, it opened up like the hood of a sportscar :) (IMG) This would be hard to draw, so here's just the picture ;) So we see an board with the crt driving circuitry, and the metal case on the left houses the power supply. At this point I was a little worried because you can see some blackened metal in one spot on the PSU. I tried to peek within and the components there didn't look obviously damaged- but of course I can only tell so much without opening the power supply cover. Instead I opted for a quick measure of the outputs, which seemed fine. I closed the cover backup, and re-inserted the main board module, and decided to just go for it, and sure enough, it powered up into it's built-in test mode. (IMG) First power-on picture. # Day one Alright, so now I had to figure out how to actually talk to this thing. It has a db25 connector on the back labeled "J1/Data Set", which I assume is where the electrons are supposed to enter. Hoping that it's just a plain db25 serial connector like any other terminal, I hook up a db25->db9 null-modem cable I have laying around. I was using this cable with my panasonic luggable in the past, so I know it should at least work in theory, if it were plain serial. After hooking it up and messing about a bit with various stty settings I do get garbage on the screen when I press keys on the terminal. To my surprise i had to use 7 bits per character instead of the usual 8 (cs7) - but unfortunately, I can only get data in one direction; pressing keys on the terminal makes characters show up in my screen session, but not the other way around. I was expecting at least some garbage characters even if the settings were not correct, but nothing. Well, darn. (IMG) Back connectors (1) (IMG) Back connectors (2) # Day two So, the fact that I got readable characters in one direction is actually very good news. This meant that it's talking plain 'ol serial as I had hoped. The next step was to make a cable and see if I could figure out what other pin the terminal might receive data on. I got a few of those screw-terminal db25 and db9 connectors, and cut up a piece of scrap serial cable I had laying around, and wired up a plain full null-modem cable as a starting point. Unsurprisingly, the homemade null-modem cable gave exactly the same result as the commercial one. So then I went and took a closer look at what all the 'extra' pins on a db25 serial connector are for. It turns out there's actually a second set of data pins, there is a second Read/Transmit-Data pins, etc,... As a complete stab in the dark I tried bridging the normal RD pin with the RD(2) pin, and to my surprise I now had everything working in both directions! I don't know WHY the read-data needs to go to the second one instead of the same set the TXD goes to, but it is what it is! (If anyone knows, let me know!) - I couldn't find any technical documentation for this terminal, just a few (very cool) sales brochures. After messing with my Linux machine's inittab and trying varous TERM variables, I managed to ssh to sdf and open up commode: (IMG) Wiring of the connector (IMG) Commode (IMG) Commode (close-up) (TXT) Wiring diagram # Day three Alright, so now I've got a somewhat usable terminal. What's left, you ask? Well! It's not quite perfect, you see. When I open up vim, everything just sort of scrolls off-screen and the terminal makes a bunch of unhappy bleeps. No, we can not just leave it at that. We have to figure out what the appropriate TERM variable is for this thing and see what else it can do. Some of the marketing material mentioned it being able to do line graphics, and potentially other fancy stuff by sending it SI/SO control characters and what not. Given the lack of any real documentation, I decided to write a little program that allows me to send it data in a controlled way. (IMG) Some output of the test program As you can see in the above photo, I did end up figuring out how to toggle the line-graphics mode, well - i'm getting ahead of myself - the FIRSt thing I noticed was that I could send it VT52 control characters, like for instance \033A to move the cursor up, but -not- ANSI control characters like \033[A - For this reason I settled on the VT52 TERM variable/termcap file. Although it's not quite perfect. Vim is still broken; and when looking at the documentation of the VT52, it's supposed to enter line-graphics mode with \033F and exit it with \033G ; but for this terminal it is exactly backwards! It enters line-graphics mode with \033G and exits it with \033F - I thought the wikipedia page of the VT52 was backards first, until I went and looked up the actual old manual and confirmed it there (unless the original manual was backwards and wikipedia copied the mistake, which is of course also possible but unlikely) - so for now I will assume that this honeywell terminal is backwards from the VT52 - which is actually kind of funny. So with that in mind, it seems obvious that I will have to do more testing, and craft up my own termcap file for this thing. Which, I haven't finished yet at the time of writing, but when and if I do, I'll put it up here along with the other documentation and findings of my experimentation. The other thing is, if you notice in the pictures, there's some diagonal lines going across - that's the horizontal return being slightly 'off' - it probably needs some caps replaced, so that's another thing on the todo list. I hope you enjoyed my little story! :) # Update I've managed to "fix" the CRT so it no longer looks like a wash of green with diagonal lines. It just needed a bit of tuning on the inside. The pcb for the CRT has a bunch of potentiometers and variable coils for tuning, as they typically do. There was a tunable coil for the horizonal width and the brightness, after adjusting that, it looks so much better! Here's the result: (IMG) Fixed crt ______________________________________________________________________ Gophered by Gophernicus/3.0.1 on FreeBSD/amd64 14.0