[HN Gopher] Building an IBM 3270 terminal controller
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Building an IBM 3270 terminal controller
Author : Aloha
Score : 43 points
Date : 2024-04-26 19:15 UTC (2 days ago)
(HTM) web link (ajk.me)
(TXT) w3m dump (ajk.me)
| lambdaone wrote:
| This is magnificent reverse engineering. I wonder why
| retrocomputing is so fascinating? Is it an attempt (by older
| people) to rediscover their youth, or is it a search for a golden
| age of computing where people still had some autonomy over their
| hardware? Or something else?
| blame-troi wrote:
| I suspect it's the same appeal as woodworking or hor rodding or
| living history reenactment.
| MSFT_Edging wrote:
| Humans also love their tools. While tools get more advanced,
| they sometimes lose some charm or benefits of older tools.
|
| For me, an interest in retro tech is seeing how people did
| things in the past and realizing we lost some "nice"
| experiences along the way.
|
| Also, in a world where everything becomes obsolete at record
| speeds, something so obsolete feels stuck in time.
| wkat4242 wrote:
| > Humans also love their tools. While tools get more
| advanced, they sometimes lose some charm or benefits of
| older tools.
|
| This is true. In summer when I sit in the dark with the
| windows open (hot country and no AC and I don't want to
| attract bugs), my 4K computer monitor is totally incapable
| of dimming to a level that doesn't blind me. Even with
| white on black/dark mode and brightness set to 0. In fact,
| even during the day I work with brightness 0 on that thing,
| it seems all monitors are optimised for max brightness
| these days.
|
| Meanwhile, my old VT520 terminal has an analog brightness
| dial which I can turn so low that I can barely make out the
| letters in a pitch-black room <3
| twoodfin wrote:
| Personally, I'm interested in getting to learn about and play
| with toys that had insurmountable (to me) barriers of cost,
| access, or obscurity when they were contemporary.
|
| The purest "retro" experience I've had wasn't retro at all:
| Stepping into an MIT Athena lab a quarter century ago to see an
| SGI Indy ready for my login.
|
| In a way, it's like finding out what winning the lottery would
| have meant for a curious tech nerd.
| icedchai wrote:
| Yes. I bought an SGI O2 and a NextStation off of ebay for
| those reasons. I could've never afforded this stuff when it
| was new.
| wkat4242 wrote:
| Ooh the O2 was a beautiful system. In fact all their
| systems looked amazing. Where all the others made all this
| super-boring businessy stuff. Well, except Sun, they had
| style but not too explicit, they were kinda in the middle.
|
| But HP and IBM made boring old boxes :P I did love HP-UX
| though.
| wkat4242 wrote:
| Yeah I'd love to play around with a real IBM Mainframe.
|
| However even in these days they are expensive, plus I don't
| have the space or power requirements for one of those :)
| There's are reason they were called "big iron".
| EvanAnderson wrote:
| I love machines where the complexity is such that a single
| person can have an almost complete understanding of the
| entirety of the machine. You can get that from old machines.
| glhaynes wrote:
| There's also an enjoyment in revisiting the old stuff while
| standing on its shoulders.
|
| For example, there are modern games made by hobbyists for old
| systems that completely outclass literally anything that was
| available contemporaneously. Today anyone with a computer has
| access to development hardware, software, documentation, and
| community resources that are all just lightyears beyond what
| was available then at any price. Changing a few lines of code
| and instantly hopping into a cycle-accurate emulator to test
| takes milliseconds versus writing out floppies or EEPROMs.
| Arcane tricks that only a privileged few knew (if that) are now
| common knowledge. That stuff leads to whole other strata of
| capabilities being accessible.
| wkat4242 wrote:
| I love old terminals. I used to sit at the ones in the library
| for ages (I often managed to 'escape' into the data controller
| somehow :P ). And at college, all the X-Terminals were often
| occupied because they were the only way to run NSCA Mosaic to see
| this cool new "Internet" stuff. Meaning the rooms full of green
| screen terminals were completely deserted. I usually took two for
| myself (This was before I learned of Gnu Screen and tmux lol)
|
| I still have my own VT520 <3 Not getting rid of it (my girlfriend
| keeps asking why do I keep that old thing around, grrr)
| Aloha wrote:
| My WYSE 180E is still sitting in the garage for much the same
| reasons.
|
| I used that every day as my daily driver terminal for 10-12
| years - I got it was what was effectively NOS, so zero hours on
| the tube. I've not turned it on I think in 8 or 10 years.
|
| I'll drag it out once I clean up the garage this summer.
| wkat4242 wrote:
| Yeah my VT520 is also very clean. Unfortunately though it's
| one of the later ones sold by Boundless. The same thing but
| not the DEC logo, and that matters a bit.
|
| App support is pretty horrible these days though. Most apps
| don't bother reading termcap/terminfo anymore and just blast
| Xterm whatever to the terminal :) That makes the
| functionality a bit limited.
|
| I did some of my best work on those terminals though.
| Especially because they didn't have a browser. Very
| distraction-free. I can see why this works out so wel for
| people like George R.R. Martin.
| Aloha wrote:
| Putting screen in the middle is actually _the_ fix for that
| - Screen has been very good for me at acting as a decent
| translation layer for misbehaving apps.
| wkat4242 wrote:
| Huh I never thought of that. Thanks!!
| Aloha wrote:
| Its one of the two reasons I've never switched to tmux -
| the other is habit, I have a well formed .screenrc and
| I'm used to it.
| wkat4242 wrote:
| I was a screen holdout for a long time too but in the end
| tmux won me over :) But I still know screen very well.
|
| So tmux doesn't do this well either? Too bad. I'm not
| surprised screen does it well though, with its long
| history.
|
| By the way one thing that's a bit sad about the VT520 is
| that it looks really boring. It has a standard "VGA
| Monitor from the 90s" look. The great thing is that it
| takes standard PS/2 keyboards unlike the previous special
| ones. But the VT220 and VT320 looked much cooler.
|
| Not to mention the VT05 by the way, that was straight out
| of star trek <3 It was deep as hell though, no way that
| would fit on a modern desk. It didn't even have a CPU, it
| was full of boards of discrete logic.
| Aloha wrote:
| tmux might work - I tested early with tmux but the last
| time I bothered was pre-1.0 versions of tmux. Screen
| supports it well, but tmux is probably worth testing.
| throwawayForMe2 wrote:
| I spent a number of years pounding out code on 327x terminals.
| They were built like tanks.
| Aloha wrote:
| I'd love an actual 327x family terminal - they're very well
| build, and the inbuilt font set is rather visually appealing.
| tyfon wrote:
| I work in a bank, and we still have to drop into "3270" from time
| to time to modify stuff in the core.
|
| The gui apps connected to it are just sending the data stream in
| the background.
|
| Long lasting technology really.. But we're on the way to replace
| the core now.. Not looking forward to it tbh!
| kens wrote:
| The article mentions various old chips that interface to the 3270
| data stream. Does anyone know what the similar chips are to
| interface to IBM's bus-and-tag? I saw bus-and-tag interface chips
| that converted the weird voltage levels a few years ago but lost
| the part number and haven't been able to find them since.
| AstroJetson wrote:
| One of the features of OS/2 was it could act as a terminal
| controller. One day people started having problems with their
| terminals. Response times were getting slower and slower and
| finally they ground to a halt.
|
| From across the cube farm there was an "oh no" Turns out that our
| co-worker didn't attach to the dev system, he attached to the
| production environment. As users detached sessions and
| reconnected, they connected to his desktop. As his desktop got
| more and more sessions, they got slower and slower.
|
| Lucky for him it was only our building, the main phone center
| wasn't involved.
|
| Still think of you buddy, one of my favorite "back in the day"
| stories.
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