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I’m one of those youngish programmers who has never really worked on anything but Linux, so the idea of these IBM operating systems is pretty foreign to me. The

I’m one of those youngish programmers who has never really worked on anything but Linux, so the idea of these IBM operating systems is pretty foreign to me. The article describes System i as “very advanced” but I have never even really heard of anyone using it or referencing it. How do you write and deploy software for these things? I am so used to just being able to, like, build a Go binary and run it on a Linux box. Are they better in some ways that I am missing out on? Just curious.

trollopTheJope 9y ago
if you can't just build your Go binary and run it on your Linux box, is it even, like, worth knowing? I'll bet the author hasn't even heard of Go or Linux boxes, like. "very advanced"? according to, like, whom? /me resumes hacking go program on linux box
bluedino 9y ago
Zend has a full PHP environment for the i, and you can install things like Apache and MySQL on it. You can even virtualize Linux on it. Most older programs are written in RPG but there are ways to write programs in other language like C or COBOL. You can use tools like IBM VisualAge to have a "modern" environment instead of hammering away at green screen text terminals. It's a very odd environment, unlike both Windows and UNIX. There is a job scheduler, output queues, print devices, security levels, objects... Check out the young i developers group if you want to learn more. They embrace modern tech like node and github http://yips.idevcloud.com/wiki/ http://yips.idevcloud.com/wiki/
snuxoll 9y ago
IBM i is advanced in some interesting ways, but the design has plenty of drawbacks. The database (DB2) is baked right into the operating system and is an integral component virtually every application relies on it - you can access tables via SQL or directly through record access (equivalent to fopen(), but against database tables). In fact, the “traditional” UNIX like filesystem (the IFS) on IBM I is an entirely different world, the object storage subsystem (the database) is where 99% of everything live on IBM I including most applications. Applications aren’t compiled to machine code directly, outside the lowest level code needed to get the system running - they’re all stored as bytecode and compiled to machines code on first run, which is how IBM has taken advantage of newer POWER releases without requiring customers beg vendors to upgrade or rebuild their code. There’s a hell of a lot more, but these are two key components of the design. As for writing software, you basically have no choice but to use tooling IBM has support for. There is a emulated POSIX environment (PASE) but it’s mostly used by IBM to port things from AIX - the traditional IBM i languages are RPG plus C/C++ as a newer addition, but they have runtimes for Java, Python, Node and a few others. The traditional languages are the only way you have to make classic green screen apps, while the latter are there primarily to host web applications.
- krylon 9y ago
  > but the design has plenty of drawbacks As somebody who has never been near an AS/400, what are those drawbacks? Besides the environment being weird in the sense that it is unlike anything else? The only bad thing I have ever someone say about the AS/400 was a supervisor I worked for during my training who had at one point written RPG programs, and she said ... some pretty unfriendly things about RPG. Which is not say that's the only problem; like I said, I have no knowledge of the system beyond what Wikipedia tells me about it.
  - snuxoll 9y ago
    There’s extremely limited compatibility with POSIX software, PASE exists but you aren’t just going to be porting applications with minimal or zero effort. Honestly IBM i makes little sense as a modern application platform, and DB2 for i is wonky plus licensing for it sucks (if you’re connecting from anything but Java where you can use open source drivers expect to pay through the node for DB2 Connect unless your application also runs on i).
- DrScump 9y ago
  As for writing software, you basically have no choice but to use tooling IBM has support for. Is that really the case now? Even back in the 1980s, other software publishers made great tools and compilers for OS/MVS mainframes. Boole and Babbage's Resolve did a lot of cool stuff, including giving you the mainframe equivalent of "su" right down to the TSO terminal level. And we didn't even use IBM compilers; Capex had optimized compilers with great system dump formatting.
pjmlp 9y ago
IBM i, aka AS/400 is indeed quite advanced. It was developed in PL/S, a PL/I dialect, back when C was only relevant inside AT&T walls. The binaries use a bytecode format known as TIMI, and IBM i contains a kernel level JIT. So any application gets AOT compiled at installation time, or when you feel like refreshing their native image. The filesystem is follows a database model known as catalog. Main programming languages on the classical mainframe environment are RPG II, Fortran, Cobol, PL/S, C, C++ and Java. Yes, IBM i Java makes use of TIMI bytecodes as well. Then there is the POSIX emulation layer to help port UNIX applications into IBM i. At old good mainframe fashion, these environments are each its own little world. When the need to modernize IBM i came to be, IBM started porting PL/S code to C++. If one wants to actually target native code and not TIMI, there is a C compiler called Metal C. This is just about IBM i, IBM z and Unisys ClearPath are also quite interesting. All written in systems programming languages much safer than straight C, and with lots of nice features which UNIXes still haven't adopted.
- mdaniel 9y ago
  Unisys ClearPath I've been trying to find an emulator for Unisys for years, as I've come in contact with those systems twice in my career, but both times it was "oh, those are used by [hushed tones] the legacy team" which isn't good for learning about how they work. Do you know of something akin to Hercules, or even eBay something, which would allow a sufficiently curious person to kick to the tires on a Unisys OS?
  - LittleAthena 9y ago
    They have a free education/hobbyist version officially available that runs as a VM on top of Windows. (http://www.unisys.com/offerings/clearpath-forward/clearpath-forward-products/clearpath-mcp-software/clearpath-mcp-express/story/clearpath-mcp-express-id-2548 http://www.unisys.com/offerings/clearpath-forward/clearpath-...)
  - deleted 9y ago
    [deleted]
  - JasonFruit 9y ago
snaky 9y ago
i Series (System/38, AS/400) is very interesting to learn about, even today. "Inside the AS/400" book by Frank G. Soltis is good, "AS/400: Designed for the Cloud" video (https://www.youtube.com/watch?v=0dTZVyRDnds https://www.youtube.com/watch?v=0dTZVyRDnds) is inspiring, and "Laughing Boardroom" commercials series aren't bad either.
- snaky 9y ago
  Current state of affairs in IBM i world https://www.itjungle.com/2017/12/13/2017-ibm-year-review/ https://www.itjungle.com/2017/12/13/2017-ibm-year-review/ https://www.itjungle.com/2017/06/21/seven-bright-spots-ponder-as400s-29th-birthday/ https://www.itjungle.com/2017/06/21/seven-bright-spots-ponde...

trollopTheJope 9y ago

if you can't just build your Go binary and run it on your Linux box, is it even, like, worth knowing? I'll bet the author hasn't even heard of Go or Linux boxes, like. "very advanced"? according to, like, whom? /me resumes hacking go program on linux box

bluedino 9y ago

Zend has a full PHP environment for the i, and you can install things like Apache and MySQL on it. You can even virtualize Linux on it. Most older programs are written in RPG but there are ways to write programs in other language like C or COBOL. You can use tools like IBM VisualAge to have a "modern" environment instead of hammering away at green screen text terminals. It's a very odd environment, unlike both Windows and UNIX. There is a job scheduler, output queues, print devices, security levels, objects... Check out the young i developers group if you want to learn more. They embrace modern tech like node and github http://yips.idevcloud.com/wiki/ http://yips.idevcloud.com/wiki/

snuxoll 9y ago

IBM i is advanced in some interesting ways, but the design has plenty of drawbacks. The database (DB2) is baked right into the operating system and is an integral component virtually every application relies on it - you can access tables via SQL or directly through record access (equivalent to fopen(), but against database tables). In fact, the “traditional” UNIX like filesystem (the IFS) on IBM I is an entirely different world, the object storage subsystem (the database) is where 99% of everything live on IBM I including most applications. Applications aren’t compiled to machine code directly, outside the lowest level code needed to get the system running - they’re all stored as bytecode and compiled to machines code on first run, which is how IBM has taken advantage of newer POWER releases without requiring customers beg vendors to upgrade or rebuild their code. There’s a hell of a lot more, but these are two key components of the design. As for writing software, you basically have no choice but to use tooling IBM has support for. There is a emulated POSIX environment (PASE) but it’s mostly used by IBM to port things from AIX - the traditional IBM i languages are RPG plus C/C++ as a newer addition, but they have runtimes for Java, Python, Node and a few others. The traditional languages are the only way you have to make classic green screen apps, while the latter are there primarily to host web applications.

krylon 9y ago
> but the design has plenty of drawbacks As somebody who has never been near an AS/400, what are those drawbacks? Besides the environment being weird in the sense that it is unlike anything else? The only bad thing I have ever someone say about the AS/400 was a supervisor I worked for during my training who had at one point written RPG programs, and she said ... some pretty unfriendly things about RPG. Which is not say that's the only problem; like I said, I have no knowledge of the system beyond what Wikipedia tells me about it.
- snuxoll 9y ago
  There’s extremely limited compatibility with POSIX software, PASE exists but you aren’t just going to be porting applications with minimal or zero effort. Honestly IBM i makes little sense as a modern application platform, and DB2 for i is wonky plus licensing for it sucks (if you’re connecting from anything but Java where you can use open source drivers expect to pay through the node for DB2 Connect unless your application also runs on i).
DrScump 9y ago
As for writing software, you basically have no choice but to use tooling IBM has support for. Is that really the case now? Even back in the 1980s, other software publishers made great tools and compilers for OS/MVS mainframes. Boole and Babbage's Resolve did a lot of cool stuff, including giving you the mainframe equivalent of "su" right down to the TSO terminal level. And we didn't even use IBM compilers; Capex had optimized compilers with great system dump formatting.

pjmlp 9y ago

IBM i, aka AS/400 is indeed quite advanced. It was developed in PL/S, a PL/I dialect, back when C was only relevant inside AT&T walls. The binaries use a bytecode format known as TIMI, and IBM i contains a kernel level JIT. So any application gets AOT compiled at installation time, or when you feel like refreshing their native image. The filesystem is follows a database model known as catalog. Main programming languages on the classical mainframe environment are RPG II, Fortran, Cobol, PL/S, C, C++ and Java. Yes, IBM i Java makes use of TIMI bytecodes as well. Then there is the POSIX emulation layer to help port UNIX applications into IBM i. At old good mainframe fashion, these environments are each its own little world. When the need to modernize IBM i came to be, IBM started porting PL/S code to C++. If one wants to actually target native code and not TIMI, there is a C compiler called Metal C. This is just about IBM i, IBM z and Unisys ClearPath are also quite interesting. All written in systems programming languages much safer than straight C, and with lots of nice features which UNIXes still haven't adopted.

mdaniel 9y ago
Unisys ClearPath I've been trying to find an emulator for Unisys for years, as I've come in contact with those systems twice in my career, but both times it was "oh, those are used by [hushed tones] the legacy team" which isn't good for learning about how they work. Do you know of something akin to Hercules, or even eBay something, which would allow a sufficiently curious person to kick to the tires on a Unisys OS?
- LittleAthena 9y ago
  They have a free education/hobbyist version officially available that runs as a VM on top of Windows. (http://www.unisys.com/offerings/clearpath-forward/clearpath-forward-products/clearpath-mcp-software/clearpath-mcp-express/story/clearpath-mcp-express-id-2548 http://www.unisys.com/offerings/clearpath-forward/clearpath-...)
- deleted 9y ago
  [deleted]
- JasonFruit 9y ago

snaky 9y ago

i Series (System/38, AS/400) is very interesting to learn about, even today. "Inside the AS/400" book by Frank G. Soltis is good, "AS/400: Designed for the Cloud" video (https://www.youtube.com/watch?v=0dTZVyRDnds https://www.youtube.com/watch?v=0dTZVyRDnds) is inspiring, and "Laughing Boardroom" commercials series aren't bad either.

snaky 9y ago
Current state of affairs in IBM i world https://www.itjungle.com/2017/12/13/2017-ibm-year-review/ https://www.itjungle.com/2017/12/13/2017-ibm-year-review/ https://www.itjungle.com/2017/06/21/seven-bright-spots-ponder-as400s-29th-birthday/ https://www.itjungle.com/2017/06/21/seven-bright-spots-ponde...