4 ms·

The oldest one I know is PDP-11. It's still being used in nuclear power plants and many plants will continue using it until at least 2050 (maybe even longer if

by Jerry2 5y ago

The oldest one I know is PDP-11. It's still being used in nuclear power plants and many plants will continue using it until at least 2050 (maybe even longer if they remain working). [1] PDP-11 was released in 1970 so your TSOS find is even older. I'm sure there's something even older than these two that's being used by various gov orgs and industrial systems. There's plenty of small consulting firms that support ancient systems. These contracts provide them with steady and stable income. [1] https://www.theregister.co.uk/2013/06/19/nuke_plants_to_keep_pdp11_until_2050/ https://www.theregister.co.uk/2013/06/19/nuke_plants_to_keep...

sloaken 5y ago
PDP-11 Assembly language is just beautiful, well compared to most other assembly languages. I highly recommend it if you are trying to learn the concept of doing assembly language as a 'trainer' language. Not practical these days but a great way to learn.
ghaff 5y ago
Used != supported especially for systems that are not network-connected. Also the PDP-11 is a minicomputer series. There were a bunch of operating systems from DEC and others that ran on it. Certainly there are consultants who support ancient system but they probably have limited (if any) access to the OS source code--though they can probably patch to a limited degree.
- cptnapalm 5y ago
  BSD 2.11 is still getting patched by Steve Schultz, last I saw.
  - paulmd 5y ago
    Apropos of nothing but this is one of the fun bits about FreeBSD, you can trace a lineage back through the AT&T Research Unix days. The oldest (known) surviving code in FreeBSD dates back to November 1974, committed by Ken Thompson. https://www.researchgate.net/figure/The-oldest-surviving-code-in-a-2016-version-of-Freebsd-Unix-lines-114-118_fig12_306070534 https://www.researchgate.net/figure/The-oldest-surviving-cod...
- SilasX 5y ago
  Sufficiently advanced long-term maintenance via patches seems indistinguishable from providing support.
  - edgyquant 5y ago
    I’d say support is more official than paying a contractor
kragen 5y ago
PDP-11 isn't an OS.
- egberts1 5y ago
  a ginormous scripting OS, PDP/11 is.
- p_l 5y ago
  What's more, when it comes to computer architectures, even among Digital it's not the oldest nor still supported. Because you can still buy a new PDP-10 (well, PDP-10 compatible, iirc a lot of I/O is different, but it can run TOPS-20 V7 with patches) Of course S/360 has longer continuity of hw/sw combination.
  - kragen 5y ago
    You can't buy it from Digital, and TOPS-20 isn't still supported.
  - skissane 5y ago
    > Because you can still buy a new PDP-10 (well, PDP-10 compatible, iirc a lot of I/O is different, but it can run TOPS-20 V7 with patches) Who is still selling new PDP-10-compatibles? Systems Concepts? XKL?
    - p_l 5y ago
      XKL is still around and makes PDP-10-on-a-chip for internal use, some people managed to get just the PDP-10 part sold.
      - skissane 5y ago
        XKL is still around indeed, but do they still manufacture the TOAD-2 CPUs? Do they still use it in their current products? The TOAD-2 dates from around 2005 or so, it was designed to be used as a service/management processor in XKL's optical routers, although it could run a patched version of TOPS-20. But do XKL's current products still use it? I can't find any information on whether or not they do, but I'd be surprised if they were still using a 15+ year old part in their latest products.
drewzero1 5y ago
This is a good answer to another question: what is the oldest computer family/architecture still in use? I'm sure there are other contenders out there, especially with modern descendants of old architectures and different interpretations of the question. I'd be interested in hearing about others as well. I believe my employer's PDP-11 ran RSTS/E or some variant, and the software was written in BASIC by my current boss. There were a lot of operating systems available for the PDP-11 for a lot of different contexts (including UNIX).
- paulmd 5y ago
  Depending on how you delineate the families, the origins of x86 date back to 1972 (Intel 8008) and obviously x86 itself dates to 1978 ;) Z80 also dates back a really long time, and there is a ton of stuff that still uses Z80-family processors in many embedded applications (microwaves, calculators, etc). I realize neither of those are probably the absolute oldest, but this is going to hinge on what each commenter's exact definition of "families" and "still in use" are. Active development/new chips being released? Still in widespread legacy use? One-off legacy systems still hanging on in an industrial installation somewhere? In terms of what is the absolute oldest - again depending on your exact definition of "family", z/System is arguably the oldest computer family, you can trace a direct lineage back to punchcard tabulation programs, which date back into the 1880s. z/OS systems can run programs originally compiled for System/360, which was designed to be directly ported from plugboard programs for programmable tabulators, so in a "ship of theseus" sense that is likely the oldest computer family.
  - klelatti 5y ago
    The 8008 ISA comes from the Datapoint 2200 which was released in 1971 - although work started earlier. Intel (and TI) were asked to develop single chip implementations which CTC never used. https://en.wikipedia.org/wiki/Datapoint_2200 https://en.wikipedia.org/wiki/Datapoint_2200
retrac 5y ago
I seriously considered applying for that job! I'm probably 30 years younger than anyone with real PDP-11 experience but I got a background in programming tiny embedded systems, with some robotics. And I love computer history with a particular soft spot for the PDP-11. (I've got an LSI-11 in the basement somewhere.) But then I thought about it. Tracing race conditions in PDP-11 code all day seems like the surest way to kill all love for my hobby. Anyway, the PDP-11 wasn't really an OS but an architecture (like ARM or x86). The robotics software in question probably runs bare metal. It was very, very popular and will indeed remain around in pockets (in emulation) probably until the 22nd century. Ain't broke? Don't fix.

by Jerry2 5y ago

sloaken 5y ago

PDP-11 Assembly language is just beautiful, well compared to most other assembly languages. I highly recommend it if you are trying to learn the concept of doing assembly language as a 'trainer' language. Not practical these days but a great way to learn.

ghaff 5y ago

Used != supported especially for systems that are not network-connected. Also the PDP-11 is a minicomputer series. There were a bunch of operating systems from DEC and others that ran on it. Certainly there are consultants who support ancient system but they probably have limited (if any) access to the OS source code--though they can probably patch to a limited degree.

cptnapalm 5y ago
BSD 2.11 is still getting patched by Steve Schultz, last I saw.
- paulmd 5y ago
  Apropos of nothing but this is one of the fun bits about FreeBSD, you can trace a lineage back through the AT&T Research Unix days. The oldest (known) surviving code in FreeBSD dates back to November 1974, committed by Ken Thompson. https://www.researchgate.net/figure/The-oldest-surviving-code-in-a-2016-version-of-Freebsd-Unix-lines-114-118_fig12_306070534 https://www.researchgate.net/figure/The-oldest-surviving-cod...
SilasX 5y ago
Sufficiently advanced long-term maintenance via patches seems indistinguishable from providing support.
- edgyquant 5y ago
  I’d say support is more official than paying a contractor

kragen 5y ago

PDP-11 isn't an OS.

egberts1 5y ago
a ginormous scripting OS, PDP/11 is.
p_l 5y ago
What's more, when it comes to computer architectures, even among Digital it's not the oldest nor still supported. Because you can still buy a new PDP-10 (well, PDP-10 compatible, iirc a lot of I/O is different, but it can run TOPS-20 V7 with patches) Of course S/360 has longer continuity of hw/sw combination.
- kragen 5y ago
  You can't buy it from Digital, and TOPS-20 isn't still supported.
- skissane 5y ago
  > Because you can still buy a new PDP-10 (well, PDP-10 compatible, iirc a lot of I/O is different, but it can run TOPS-20 V7 with patches) Who is still selling new PDP-10-compatibles? Systems Concepts? XKL?
  - p_l 5y ago
    XKL is still around and makes PDP-10-on-a-chip for internal use, some people managed to get just the PDP-10 part sold.
    - skissane 5y ago
      XKL is still around indeed, but do they still manufacture the TOAD-2 CPUs? Do they still use it in their current products? The TOAD-2 dates from around 2005 or so, it was designed to be used as a service/management processor in XKL's optical routers, although it could run a patched version of TOPS-20. But do XKL's current products still use it? I can't find any information on whether or not they do, but I'd be surprised if they were still using a 15+ year old part in their latest products.

drewzero1 5y ago

This is a good answer to another question: what is the oldest computer family/architecture still in use? I'm sure there are other contenders out there, especially with modern descendants of old architectures and different interpretations of the question. I'd be interested in hearing about others as well. I believe my employer's PDP-11 ran RSTS/E or some variant, and the software was written in BASIC by my current boss. There were a lot of operating systems available for the PDP-11 for a lot of different contexts (including UNIX).

paulmd 5y ago
Depending on how you delineate the families, the origins of x86 date back to 1972 (Intel 8008) and obviously x86 itself dates to 1978 ;) Z80 also dates back a really long time, and there is a ton of stuff that still uses Z80-family processors in many embedded applications (microwaves, calculators, etc). I realize neither of those are probably the absolute oldest, but this is going to hinge on what each commenter's exact definition of "families" and "still in use" are. Active development/new chips being released? Still in widespread legacy use? One-off legacy systems still hanging on in an industrial installation somewhere? In terms of what is the absolute oldest - again depending on your exact definition of "family", z/System is arguably the oldest computer family, you can trace a direct lineage back to punchcard tabulation programs, which date back into the 1880s. z/OS systems can run programs originally compiled for System/360, which was designed to be directly ported from plugboard programs for programmable tabulators, so in a "ship of theseus" sense that is likely the oldest computer family.
- klelatti 5y ago
  The 8008 ISA comes from the Datapoint 2200 which was released in 1971 - although work started earlier. Intel (and TI) were asked to develop single chip implementations which CTC never used. https://en.wikipedia.org/wiki/Datapoint_2200 https://en.wikipedia.org/wiki/Datapoint_2200

retrac 5y ago

I seriously considered applying for that job! I'm probably 30 years younger than anyone with real PDP-11 experience but I got a background in programming tiny embedded systems, with some robotics. And I love computer history with a particular soft spot for the PDP-11. (I've got an LSI-11 in the basement somewhere.) But then I thought about it. Tracing race conditions in PDP-11 code all day seems like the surest way to kill all love for my hobby. Anyway, the PDP-11 wasn't really an OS but an architecture (like ARM or x86). The robotics software in question probably runs bare metal. It was very, very popular and will indeed remain around in pockets (in emulation) probably until the 22nd century. Ain't broke? Don't fix.