12 ms·

But that's entirely my point, yeah. I don't know if a single-level store address space is better, but if the reason for its decline on IBM i is merely that main

by anyfoo 6y ago

But that's entirely my point, yeah. I don't know if a single-level store address space is better, but if the reason for its decline on IBM i is merely that mainstream software doesn't mesh well with it, I feel like it doesn't tell me much about the paradigm itself. By the way, I'd argue about whether all of b) is technically inferior or not. Object name limits certainly are, but I got to really know data entry with block mode terminals long, long after its hey day (I've certainly come across it back then, but I was rarely a user). I feel that it can be enormously efficient for data entry and maintenance tasks. Many a person who had to move from intensive use of a block mode data entry terminal to performing the same tasks with a web app got quite annoyed at the clumsiness of it all. The web was not created for "business apps" but for hypertext document retrieval, the other uses got bolted on and it still very much shows. It's sad, because proper terminal emulation well used to be a ubiquitous feature of the Internet, before browsers took over almost entirely.

skissane 6y ago
> but I got to really know data entry with block mode terminals long, long after its hey day (I've certainly come across it back then, but I was rarely a user) I don't think block mode terminals are necessarily inferior. I see some big problems with 5250 though. The biggest is EBCDIC. Another big problem is character-at-a-time interfaces let you build things like text editors (vim and emacs), spreadsheets (like Lotus 123), etc. Sure you can build a text editor for a block mode terminal (SEU on IBM i, XEDIT on z/VM, ISPF EDIT on z/OS) but there are just certain features and interaction styles that vim and emacs support that block mode terminals can't do as nicely (example: interactive search). Lotus 123 was actually ported to 3270 (to run under MVS and VM/CMS), I've never used it (I would love it if someone could find a copy so I could!) but from what I've heard it was pretty clunky compared to the MS-DOS / PC version. Sometimes I think that block mode terminals could have exposed some kind of byte code to enable running some interactivity in the client. Actually real 3270s and 5250s generally had some kind of CPU in them (like an 8080) so I can't see why they couldn't have done that. And of course terminal emulators could do that. Then you could have these more flexible interaction styles that character mode terminals support even in a block mode terminal.
- anyfoo 6y ago
  > I don't think block mode terminals are necessarily inferior. I see some big problems with 5250 though. The biggest is EBCDIC. Oh yeah I agree, the actual implementation details in this case are icky. > Another big problem is character-at-a-time interfaces let you build things like text editors (vim and emacs), spreadsheets (like Lotus 123) That's true, but at the same time block mode allows for highly standardized and always latency free data entry and manipulation. I wonder if this is just a case for different technologies for different use cases. > Sometimes I think that block mode terminals could have exposed some kind of byte code to enable running some interactivity in the client. Hmm, it helps to preserve the zero latency aspect (if done correctly), but at the same time opens up the door for shoddy implementation and non-standard UX. And then I'm sure people would come up with all sorts of "UI libraries" for terminals that they think are very clever, but just make everything fragmented and clumsy again, just like I often wish that a web site was just a plain old HTML page with maybe a standard web form, instead of whatever crazy js-backed UI the web framework du jour came up with...
  - skissane 6y ago
    > That's true, but at the same time block mode allows for highly standardized and always latency free data entry and manipulation. I wonder if this is just a case for different technologies for different use cases. Other vendors – such as DEC and HP – had dual-mode ASCII terminals that normally operated in character-at-a-time mode, but had an escape sequence you could use to switch them into block mode. Maybe that's the best of both worlds. However, in practice, few apps used the block mode, even "data entry" style apps which could use it often didn't. Part of that was that using block mode basically tied you to a single brand of terminal, whereas manually generating forms using character mode was more portable. A lot of clone terminals and emulators emulate DEC VT terminals but few of those clones and emulators included the block mode functions.
    - anyfoo 6y ago
      Ah, I can totally imagine that being the case, yeah. Sigh, looks like there's no way out, we'll keep inventing ourselves into half-baked solutions on top of existing things.

by anyfoo 6y ago

skissane 6y ago

> but I got to really know data entry with block mode terminals long, long after its hey day (I've certainly come across it back then, but I was rarely a user) I don't think block mode terminals are necessarily inferior. I see some big problems with 5250 though. The biggest is EBCDIC. Another big problem is character-at-a-time interfaces let you build things like text editors (vim and emacs), spreadsheets (like Lotus 123), etc. Sure you can build a text editor for a block mode terminal (SEU on IBM i, XEDIT on z/VM, ISPF EDIT on z/OS) but there are just certain features and interaction styles that vim and emacs support that block mode terminals can't do as nicely (example: interactive search). Lotus 123 was actually ported to 3270 (to run under MVS and VM/CMS), I've never used it (I would love it if someone could find a copy so I could!) but from what I've heard it was pretty clunky compared to the MS-DOS / PC version. Sometimes I think that block mode terminals could have exposed some kind of byte code to enable running some interactivity in the client. Actually real 3270s and 5250s generally had some kind of CPU in them (like an 8080) so I can't see why they couldn't have done that. And of course terminal emulators could do that. Then you could have these more flexible interaction styles that character mode terminals support even in a block mode terminal.

anyfoo 6y ago
> I don't think block mode terminals are necessarily inferior. I see some big problems with 5250 though. The biggest is EBCDIC. Oh yeah I agree, the actual implementation details in this case are icky. > Another big problem is character-at-a-time interfaces let you build things like text editors (vim and emacs), spreadsheets (like Lotus 123) That's true, but at the same time block mode allows for highly standardized and always latency free data entry and manipulation. I wonder if this is just a case for different technologies for different use cases. > Sometimes I think that block mode terminals could have exposed some kind of byte code to enable running some interactivity in the client. Hmm, it helps to preserve the zero latency aspect (if done correctly), but at the same time opens up the door for shoddy implementation and non-standard UX. And then I'm sure people would come up with all sorts of "UI libraries" for terminals that they think are very clever, but just make everything fragmented and clumsy again, just like I often wish that a web site was just a plain old HTML page with maybe a standard web form, instead of whatever crazy js-backed UI the web framework du jour came up with...
- skissane 6y ago
  > That's true, but at the same time block mode allows for highly standardized and always latency free data entry and manipulation. I wonder if this is just a case for different technologies for different use cases. Other vendors – such as DEC and HP – had dual-mode ASCII terminals that normally operated in character-at-a-time mode, but had an escape sequence you could use to switch them into block mode. Maybe that's the best of both worlds. However, in practice, few apps used the block mode, even "data entry" style apps which could use it often didn't. Part of that was that using block mode basically tied you to a single brand of terminal, whereas manually generating forms using character mode was more portable. A lot of clone terminals and emulators emulate DEC VT terminals but few of those clones and emulators included the block mode functions.
  - anyfoo 6y ago
    Ah, I can totally imagine that being the case, yeah. Sigh, looks like there's no way out, we'll keep inventing ourselves into half-baked solutions on top of existing things.