5 ms·

> which send to/from the terminal whole screenfuls of data at a time, rather than individual characters 3270, and it's derivatives such as 6530, had (have?) a

> which send to/from the terminal whole screenfuls of data at a time, rather than individual characters 3270, and it's derivatives such as 6530, had (have?) a protect mode protocol that sends fields in much the same way as an HTTP post [1]. It doesn't seem to have been used that much on IBM's, probably due to the synchronous write-a-screen-and-wait-for-the-result readline style of programming. However, it was used extensively on the Tandem, which had an asynchronous 3-tier style architecture. 1. https://x3270.miraheze.org/wiki/3270_data_stream_protocol https://x3270.miraheze.org/wiki/3270_data_stream_protocol

mlyle 4y ago
A childhood memory from when I was little: We were at Sears, and my parents were waiting for customer service-- they were buying an appliance or something. There were terminals around, open to public use. I recognized them as 3290's from my dad's work. They had an application where you could do form work-- building up an order or searching for stock on items-- that used this protect mode. You'd fill in fields and then hit a pfkey, and wait several seconds for a result. I can't find anything about this system having ever existed online-- one of those blackholes of missing information about pre-web days. There's an interesting web site of how point-of-sale evolved at Sears and other places-- https://vintagepointofsale.com/author/jpnearl/ https://vintagepointofsale.com/author/jpnearl/ but that's not really what I'm talking about. I remember other instances of this from when I was little, too. Lots of IBMs internal applications used this whole forms interface and the lower right status HOLDING while you filled out fields. And I recall travel agents using it with SABRE, too. My memory is that it wasn't uncommon-- that a whole lot of mainframe usage looked like this: https://basis.uark.edu/frequently_asked_questions/email_notifications_of_rejected_txns.php https://basis.uark.edu/frequently_asked_questions/email_noti...
- genewitch 4y ago
  around 2001 or 2002 JCPenney got rid of their 80s era mainframes, and i got an IBM mainframe, and i can't remember if it was as/400 or rs6000, but it was two racks, with a hard drive the size of a small clothes dryer (and louder), and a 9" floppy. The IBM stuff didn't sell on ebay that well, but the cisco stuff (the second rack?) sold alright. Mostly went to repairing my junker car back then.
  - skissane 4y ago
    AS/400 and RS/6000 are not (per official IBM terminology) “mainframes”. AS/400s were classified as “midrange” systems. From the floppy, I’m guessing it was more likely to be an AS/400. (RS/6000s had them too, and they were originally invented on mainframes, where they were used for microcode updates-but I believe AS/400s dropped them later than RS/6000s and mainframes did.) Now the RS/6000 and AS/400 lines have been merged at the hardware level - but an old machine being thrown out in 2001/2002 would have been from when they were still distinct hardware.
  - jasonm23 4y ago
    9" floppy... probably not, I'm betting hypothetical money that it had a 8" floppy.
    - genewitch 4y ago
      to both you and sibling: If i had managed to get it to turn on enough to use it for anything, i'd remember a lot more about it. It was just scrap by the time i got it. we really wanted the racks.
- londons_explore 4y ago
  And in the future, this HN post will be ingested by an AI info-hunter, and it will be matched up with the birth and death records of the guy who installed that 3290 in your hometown Sears, and the person who wrote in his leaked personal diary that 'I am proud of the FORMS interface I made back in the 1980's for Sears - the staff loved it, even if the code was a mess!". By collecting all that data, the AI info-hunter will in milliseconds be able to tell a young girl 150 years from now that "Your great great grandfather was a computer man. I found 168,235 deceased people who directly used his work, and while his work never made it to the internet, there is a high probability that it is recoverable from a trash dump site in California in a red safe buried 13 yards below the surface also containing some car keys and a vintage $50 note. Shall I navigate there now?".
  - bitwize 4y ago
    Damn it, that logic Joe went on the fritz again! I don't know whether to fix him or take a hatchet to him, but until I figure that out I'm gonna unhook him and keep him locked in my basement, just to make sure he don't cause no more trouble...
kevin_thibedeau 4y ago
> had (have?) I was at my insurance agent a few weeks ago and they still had a 3270 emulator in use.
- mlyle 4y ago
  State Farm?
  - kevin_thibedeau 4y ago
    Yes
- jasonm23 4y ago
  Many insurance companies are stuck with core legacy on AS/400 (at best).
  - tssva 4y ago
    If accessing an AS/400 then likely it would be a 5250 emulator rather than a 3270.
    - skissane 4y ago
      AS/400s actually support 3270 terminals. Apps natively speak 5250, but OS/400 has a built-in 3270/5250 conversion layer. IBM wanted to sell AS/400s to their mainframe customers who had already invested heavily in 3270, insisting people had two terminals on each desk (3270 and 5250) was a non-starter, hence the emulation layer. Makes less sense now just about everyone uses emulators rather than physical terminals, especially when you can get emulators which speak both - but still supported anyway. You can set up your IBM i to accept TN3270 as well as TN5250. That said, people confusing 5250 for 3270 is more common than people actually using 3270 with an AS/400, so this is probably a case of the former rather than the later
skissane 4y ago
Saying "whole screenfuls of data at a time" was me simplifying things for the benefit of the uninitiated. In terms of what actually happens (from what I understand), the 3270 controller sends the host an interrupt to say some terminal has data ready. When the host gets around to it – on a busy mainframe system with thousands of terminals, the interrupt would be queued while the host had finished processing data from other terminals – the host would send the controller either a READ BUFFER command (which would send the host the entire contents of the screen) or a READ MODIFIED command (which would only send the modified fields). Most 3270 apps would define fields on the screen using START FIELD (SF) special characters, which is essentially what you mean by "protect mode protocol" (3270E added START FIELD EXTENDED, SFE, which allowed you to do fancier things like change the text colour, or define a field as numeric only, so the terminal would not allow alphabetic characters to be input into it), and then read only the modified fields back using READ MODIFIED. I believe READ BUFFER was mainly used for legacy applications which were written prior to the invention of READ MODIFIED (in particular applications originally written for the 3270's 1960s predecessor, the IBM 2260, which didn't have any such concept.)

mlyle 4y ago

A childhood memory from when I was little: We were at Sears, and my parents were waiting for customer service-- they were buying an appliance or something. There were terminals around, open to public use. I recognized them as 3290's from my dad's work. They had an application where you could do form work-- building up an order or searching for stock on items-- that used this protect mode. You'd fill in fields and then hit a pfkey, and wait several seconds for a result. I can't find anything about this system having ever existed online-- one of those blackholes of missing information about pre-web days. There's an interesting web site of how point-of-sale evolved at Sears and other places-- https://vintagepointofsale.com/author/jpnearl/ https://vintagepointofsale.com/author/jpnearl/ but that's not really what I'm talking about. I remember other instances of this from when I was little, too. Lots of IBMs internal applications used this whole forms interface and the lower right status HOLDING while you filled out fields. And I recall travel agents using it with SABRE, too. My memory is that it wasn't uncommon-- that a whole lot of mainframe usage looked like this: https://basis.uark.edu/frequently_asked_questions/email_notifications_of_rejected_txns.php https://basis.uark.edu/frequently_asked_questions/email_noti...

genewitch 4y ago
around 2001 or 2002 JCPenney got rid of their 80s era mainframes, and i got an IBM mainframe, and i can't remember if it was as/400 or rs6000, but it was two racks, with a hard drive the size of a small clothes dryer (and louder), and a 9" floppy. The IBM stuff didn't sell on ebay that well, but the cisco stuff (the second rack?) sold alright. Mostly went to repairing my junker car back then.
- skissane 4y ago
  AS/400 and RS/6000 are not (per official IBM terminology) “mainframes”. AS/400s were classified as “midrange” systems. From the floppy, I’m guessing it was more likely to be an AS/400. (RS/6000s had them too, and they were originally invented on mainframes, where they were used for microcode updates-but I believe AS/400s dropped them later than RS/6000s and mainframes did.) Now the RS/6000 and AS/400 lines have been merged at the hardware level - but an old machine being thrown out in 2001/2002 would have been from when they were still distinct hardware.
- jasonm23 4y ago
  9" floppy... probably not, I'm betting hypothetical money that it had a 8" floppy.
  - genewitch 4y ago
    to both you and sibling: If i had managed to get it to turn on enough to use it for anything, i'd remember a lot more about it. It was just scrap by the time i got it. we really wanted the racks.
londons_explore 4y ago
And in the future, this HN post will be ingested by an AI info-hunter, and it will be matched up with the birth and death records of the guy who installed that 3290 in your hometown Sears, and the person who wrote in his leaked personal diary that 'I am proud of the FORMS interface I made back in the 1980's for Sears - the staff loved it, even if the code was a mess!". By collecting all that data, the AI info-hunter will in milliseconds be able to tell a young girl 150 years from now that "Your great great grandfather was a computer man. I found 168,235 deceased people who directly used his work, and while his work never made it to the internet, there is a high probability that it is recoverable from a trash dump site in California in a red safe buried 13 yards below the surface also containing some car keys and a vintage $50 note. Shall I navigate there now?".
- bitwize 4y ago
  Damn it, that logic Joe went on the fritz again! I don't know whether to fix him or take a hatchet to him, but until I figure that out I'm gonna unhook him and keep him locked in my basement, just to make sure he don't cause no more trouble...

kevin_thibedeau 4y ago

> had (have?) I was at my insurance agent a few weeks ago and they still had a 3270 emulator in use.

mlyle 4y ago
State Farm?
- kevin_thibedeau 4y ago
  Yes
jasonm23 4y ago
Many insurance companies are stuck with core legacy on AS/400 (at best).
- tssva 4y ago
  If accessing an AS/400 then likely it would be a 5250 emulator rather than a 3270.
  - skissane 4y ago
    AS/400s actually support 3270 terminals. Apps natively speak 5250, but OS/400 has a built-in 3270/5250 conversion layer. IBM wanted to sell AS/400s to their mainframe customers who had already invested heavily in 3270, insisting people had two terminals on each desk (3270 and 5250) was a non-starter, hence the emulation layer. Makes less sense now just about everyone uses emulators rather than physical terminals, especially when you can get emulators which speak both - but still supported anyway. You can set up your IBM i to accept TN3270 as well as TN5250. That said, people confusing 5250 for 3270 is more common than people actually using 3270 with an AS/400, so this is probably a case of the former rather than the later

skissane 4y ago

Saying "whole screenfuls of data at a time" was me simplifying things for the benefit of the uninitiated. In terms of what actually happens (from what I understand), the 3270 controller sends the host an interrupt to say some terminal has data ready. When the host gets around to it – on a busy mainframe system with thousands of terminals, the interrupt would be queued while the host had finished processing data from other terminals – the host would send the controller either a READ BUFFER command (which would send the host the entire contents of the screen) or a READ MODIFIED command (which would only send the modified fields). Most 3270 apps would define fields on the screen using START FIELD (SF) special characters, which is essentially what you mean by "protect mode protocol" (3270E added START FIELD EXTENDED, SFE, which allowed you to do fancier things like change the text colour, or define a field as numeric only, so the terminal would not allow alphabetic characters to be input into it), and then read only the modified fields back using READ MODIFIED. I believe READ BUFFER was mainly used for legacy applications which were written prior to the invention of READ MODIFIED (in particular applications originally written for the 3270's 1960s predecessor, the IBM 2260, which didn't have any such concept.)