[HN Gopher] Show HN: Connecting an IBM 3151 terminal to a mainfr...
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Show HN: Connecting an IBM 3151 terminal to a mainframe [video]
The IBM 3151 from 1987 is an interesting ASCII terminal. Unlike
"normal" serial terminals, it not only supports the so-called
"character mode", where after each keypress there is an interaction
with the host computer (like with a Unix terminal), but it also has
a "block mode". This means, you can send it commands to define
fields for input and output on the screen (like a form to fill
out). The terminal then handles autonomously all the the user
input, and when the user is done and presses a special key (Enter
or a function key), all the entries in the form are transferred to
the host in one go. This is very similar but unfortunately not
identical to the so-called 3270 terminals used by IBM mainframe
computers. Therefore, I wrote a little C program to translate
between the differing protocols of 3270 and 3151 terminals enabling
a 3151 to be connected to a mainframe. I made a video describing a
little bit the 3151 terminal and the interface program and showing
how it looks like to work with the (emulated) mainframe on an 3151.
The source code and Windows binary are on github for you to try
out, if you happen to have a 3151 terminal. The link is in the
description of the video.
Author : norbert_kehrer
Score : 115 points
Date : 2025-04-08 12:36 UTC (10 hours ago)
(HTM) web link (www.youtube.com)
(TXT) w3m dump (www.youtube.com)
| sgt wrote:
| Very cool
| flkenosad wrote:
| We need to bring back spiral cables.
| jeffbee wrote:
| As soon as we drop the line rates back down to 1200, sure.
| Actually there are a lot of spiral cables readily available on
| the market because clicky keyboard guys resurrected the
| category but they only support the lowest and most ancient USB
| protocols.
| fancyfredbot wrote:
| This looks like a spiral cable which supports USB4 40Gbps:
|
| https://www.amazon.co.uk/AWADUO-Charging-Extension-
| Compatibl...
| ASalazarMX wrote:
| I kind of want those, but remember how hard it is to
| untangle the loops, and I'm already over it.
| successful23 wrote:
| Super cool project. The block mode on the 3151 was way ahead of
| its time -- kind of wild how it handled forms locally like that.
| Love the idea of hooking it up to a mainframe via your
| translator. Also yeah... we really need to bring back spiral
| cables.
| Aloha wrote:
| This is very cool!
|
| As someone who wishes more people got some programming exposure
| to IBM z and how it works differently than minicomputer derived
| operating systems (both *nix and Windows count here), I think
| this is awesome.
| ferguess_k wrote:
| Reading your comments, I suddenly realized that Win NT comes
| from PRISM which come from VMS so it also derived from
| minicomputer era. Interesting, never thought about that.
|
| I think MS-DOS comes from CP/M which was also sort of rooted in
| the minicomputer era.
| myrandomcomment wrote:
| Dave Cutler, the head of the NT project came from DEC where
| he did VMS. Big lawsuit when MS hired him.
|
| https://en.m.wikipedia.org/wiki/Dave_Cutler
| ferguess_k wrote:
| Yeah that's what I read in Showstoppers too.
| marcusb wrote:
| WNT = V + 1, M + 1, S + 1
| sillywalk wrote:
| "Originally, we were targeting NT to the Intel i860
| (code-named 'N-Ten)', a RISC processor that was horribly
| behind schedule. Because we didn't have any i860 machines
| in-house to test on, we used an i860 simulator. That's
| why we called it NT, because it worked on the 'N-Ten.'"
|
| -- Mark Lucovsky
|
| Distinguished Engineer, Windows Server Architect
|
| https://web.archive.org/web/20110720042038/http://www.win
| sup...
| myrandomcomment wrote:
| So NT from VMS is not true as pointed out above. However
| a funning one that is suppose to be true is from the 2001
| Space Odyssey series. The name of the insane AI was
| H.A.L.
|
| H>I
|
| A>B
|
| L>M
| rbanffy wrote:
| I found surprising that IBM's CMS had commands like "DIR" and
| "TYPE".
| rbanffy wrote:
| Indeed. The deeply alien nature of MVS and its descendants is
| fascinating. It's not only a difference in commands, but also
| the underlying concepts that don't map cleanly to concepts we
| got used to in Unix and Windows that causes a lot of confusion.
| For instance, a TSO user being unable to log in from different
| terminals at the same time confused me a lot until someone told
| me TSO users are not the same as Unix users. Also, a VM is not
| the same as a VMWare VM.
| miki123211 wrote:
| That, and datasets, which are not really hierarchical.
|
| Yes there's a hierarchy (with . as a separator), but it's
| more naming convention than a description of the underlying
| filesystem. You can create projects.foo.code.bar without
| having any entity (like a Unix directory) for projects.foo
| first.
| 7thaccount wrote:
| The IBM Z mainframes seem really neat. I don't have a use case
| for using one of course, but I wish IBM had like a weak virtual
| system for training that was open for the public to play with.
| marcusb wrote:
| Z Xplore at least used to include Z series access.
|
| https://ibmzxplore.influitive.com/users/sign_in
| ASalazarMX wrote:
| I didn't know about this! Is it truly free of charge? Seems
| too good to be true.
| vyrotek wrote:
| It is cool stuff. I got plenty of exposure. My father worked on
| airline, bank, and credit card systems. and now does work for
| the IRS on the tax processing mainframes. He's literally "old
| man yells at cloud".
| miki123211 wrote:
| Also true about IBM I (AKA AS400), which is also still in
| somewhat wide use.
|
| Most People seem to at least know that mainframes and Cobol
| exist, even if they've never seen them. IBM I (and its primary
| language, RPG) are similar in importance to the global economy
| and just as different from Nix and Windows systems, but they
| seem to be far less known.
|
| They're also far easier to get access to, there's a free modern
| system that you can get an account on at pub400.com. With Z/OS,
| you're stuck with Hercules emulating some ancient version from
| the 80's which there's barely any documentation for.
| electroly wrote:
| At an old job we had a 3151 connected to an RS/6000 with AIX
| among other Wyse serial terminals. I suspect it came with the
| RS/6000 and they bought all the cheaper Wyse terminals later.
| Purely character mode in this configuration. I had no idea it
| supported any kind of block mode. Fascinating!
| pelagicAustral wrote:
| I'm freaking out... At 50:28 he says "...everything is green..."
| when referring to the monochrome terminal of the 3151, I'm seeing
| Cyan... is this the end?
| bombcar wrote:
| That's a "green screen" that is tending cyan. As opposed to an
| orange screen.
| rbanffy wrote:
| It's the white balance of the camera. Ambient light is making
| it overcompensate the screen and make it more blue.
| reaperducer wrote:
| Block mode was sort of the text terminal version of today's web
| SPA's.
|
| I worked with one at a chemical company back in the 90's, and
| they were wonderfully efficient. Only send a single chunk of data
| when needed, not a constant stream of individual keypresses that
| have to be interpreted and processed.
| leoc wrote:
| Here's another, recently-started YT channel focussed on
| mainframes: ErnieTech's Little Mainframes
| https://www.youtube.com/channel/UCdi4FOLU9-kSiiE7tVuVyjg .
| mikerg87 wrote:
| His homepage is also a wealth of information:
| https://sites.google.com/view/ernietech/home
| zabzonk wrote:
| We connected our two IBM 4381s (VM/CMS) to our BT mega/kilostream
| serial network using VT200 (and VT00 & VT52)-emulating terminals
| via an IBM 7171 protocol converter. I had the somewhat unenviable
| task of programming this beast, but it worked well enough, and
| (like all IBM gear) was very well documented. This would be
| mid-1980s. The 7171 was good because it meant we didn't have to
| replace all our terminals.
| msla wrote:
| Huh. It actually is ASCII and not EBCDIC. I didn't know ASCII
| block mode terminals existed:
|
| https://terminals-wiki.org/wiki/index.php/IBM_3151
|
| https://www.ardent-tool.com/3151/
| rbanffy wrote:
| This is amazing. I wonder if 3270 and 5150 terminals can be set
| to an ASCII/VT100 mode - they are much more common on eBay than
| serial ones.
| anonymousiam wrote:
| Interesting. I never used much IBM hardware, and always assumed
| that their terminals used EBCDIC and not ASCII.
|
| The HP 2648A terminal also had a "block mode", and the RTE screen
| editor used it. It was one of the first screen editors I ever
| used (in 1984). (I had used WordStar on CP/M as early as 1979.)
|
| https://en.wikipedia.org/wiki/EBCDIC
|
| https://terminals-wiki.org/wiki/index.php/HP_2648A
|
| http://www.bitsavers.org/pdf/hp/1000/RTE-A/92077-90039_RTE-A...
| monocasa wrote:
| Their mainframe terminals do, and that's one of the conversions
| their script has to make.
|
| The 3151 was designed to integrate with other systems where
| ASCII was already prevalent.
| unoti wrote:
| > I never used much IBM hardware, and always assumed that their
| terminals used EBCDIC and not ASCII.
|
| Generally this is true. But around this era I used a ton of
| 3151 terminals on AIX, IBM's version of Unix. They were
| connected to the RS/6000 line of AIX machines. Good times!
| These machines, as Unix machines, talked in ASCII to their
| terminals. There was a whole line of port concentrators which
| would like you connect something like 32 ASCII terminals to a
| little block about the size of a modern ethernet router, and
| you could connect 4 of so of these blocks to a device in the
| main machine.
| awaymazdacx5 wrote:
| building compilers for discursive ASCII 3151 machine code to
| source in 3270's
|
| extricating terminal interfaces whether in binary, object-
| oriented abstracted languages is a feature in UNIX paradigms
| kjellsbells wrote:
| One of the hardest things to deal with is the accelerating loss
| of documentation of these old systems. Unless you are lucky, you
| end up spelunking around weird and not very safe looking URLs
| looking for redbooks or specs, or, like some medieval historian,
| trying to figure out what X said by reading some commentary or
| rebuttal produced decades later that mentions X.
|
| Case in point: in the late 90s I was a user of a product called
| SNAP-IX, that aimed to convert between SNA/terminals and TCP/IP
| client server. It was produced by a small UK company, Data
| Connection, that then got swallowed up and repurposed and
| ultimately eaten up by some cloud company, and all the
| documentation, manuals, specs, and knowledge evaporated. Somebody
| somewhere might have a pdf library, but you'll never find it.
| _They had kept that product going for 25 years._ Pfft. Gone.
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(page generated 2025-04-08 23:00 UTC)