6 ms·

I actually got paid a salary for learning & programming in IBM mainframe assembler (BAL or Basic Assembly Language) in 1970, for an insurance company. The CPU m

I actually got paid a salary for learning & programming in IBM mainframe assembler (BAL or Basic Assembly Language) in 1970, for an insurance company. The CPU memory was so small (32K, yes 32,768 bytes) that the only way we could squeeze enough functionality was to write in assembler, with overlays (no virtual memory). Debugging consisted of manually toggling hex data and instructions at the control panel. What a blast! It was a lot of fun, but terribly inefficient programmer productivity. I would not want to go back :o) Dereferencing registers prepared me for C pointers later.

molteanu 8y ago
Thanks for sharing
- amorousf00p 8y ago
  Shithead.
xigency 8y ago
Wow, 32K! I'm working on an Arduino Uno project where I need to squeeze some complicated logic into 2K RAM and 32K FLASH :). I haven't resorted to assembly, yet.
amorousf00p 8y ago
Whenever I see some shit like 'thanks for sharing' or 'noted' I want to kill someone. These are cautionary tales: ignore at your leisure.
- ghrifter 8y ago
  Holy shit dude, what next gonna get mad at emoji posting? Too bad I cant emoji spam on HN
- sctb 8y ago
  No matter how you feel, posting like this will get your account banned. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html
Narishma 8y ago
32KB was a ton of memory in the 70s.
- aswanson 8y ago
  Especially in 1970. That was a lot even for 1980.
- deleted 8y ago
  [deleted]
cylinder714 8y ago
Forgive me, but I'm struggling to understand how much useful work one could extract from a computer with only 32k of RAM. A microcontroller for an appliance, sure, but a mainframe? Could you tell us more about the work you were doing?
- TylerE 8y ago
  Oblig NASA factoid: The guidance computer on Apollo that got as to the moon had 4096 bytes of RAM and about 72K of ROM.
  - cylinder714 8y ago
    Whew, excellent point. That raises another question, though—how much computational work did that computer have to do? The real heavy lifting was performed by big NASA mainframes on Earth, right?
    - cbm-vic-20 8y ago
      The Apollo computer did things like control rocket burns, provide navigational information, etc. More information http://nassp.sourceforge.net/wiki/Guidance_and_Control_System http://nassp.sourceforge.net/wiki/Guidance_and_Control_Syste... The source is on Github, too, for example: https://github.com/chrislgarry/Apollo-11/blob/master/Luminary099/BURN_BABY_BURN--MASTER_IGNITION_ROUTINE.agc https://github.com/chrislgarry/Apollo-11/blob/master/Luminar...
- cylinder714 8y ago
  (An aside: do terms like "mainframe" and "microcomputer" have any meaning any more, when a Raspberry Pi Zero has orders of magnitude greater RAM and power than a '70s piece of "big iron"?)
  - joshAg 8y ago
    Yes. Mainframes still exist. IBM still sells them, and you can do things like hotswap CPUs and RAM or setup an geographically distributed HA cluster that can swap which mainframe the VMs or databases are "running" on without dropping connections, requests, or other interruptions. https://en.wikipedia.org/wiki/IBM_Z https://en.wikipedia.org/wiki/IBM_Z
cptnapalm 8y ago
Ooo! I have a question! Where do I learn more about overlays? The BSD 2.11 code I've read has comments about overlays, but I have no idea where to learn more about how to understand the topic. I came across it while I was seeing if I could get newlib to compile for the PDP-11.
- monocasa 8y ago
  Game consoles supported the concept a whole lot longer than other domains. ROM bank switching can be thought of as overlay loading, and beyond that most consoles supported overlays up until 360/PS3. The Nintendo DS cartridge format natively supported overlays for instance.
- sehugg 8y ago
  You could look at some old Turbo Pascal articles (though don't know how applicable it is to other systems): http://www.boyet.com/articles/publishedarticles/theslithytove.html http://www.boyet.com/articles/publishedarticles/theslithytov...
- ddingus 8y ago
  https://www.google.com/amp/s/www.vox.com/platform/amp/policy-and-politics/2018/7/16/17578548/voxcare-national-guideline-clearinghouse https://www.google.com/amp/s/www.vox.com/platform/amp/policy...
  - ddingus 8y ago
    Dammit. Wrong link. Here is the correct one: https://www.elsevier.com/books/linkers-and-loaders/levine/978-0-08-051031-6 https://www.elsevier.com/books/linkers-and-loaders/levine/97...
    - cptnapalm 8y ago
      Was wondering about that initial link. Thank you for returning with the correction.
      - 8y ago

molteanu 8y ago

Thanks for sharing

amorousf00p 8y ago
Shithead.

xigency 8y ago

Wow, 32K! I'm working on an Arduino Uno project where I need to squeeze some complicated logic into 2K RAM and 32K FLASH :). I haven't resorted to assembly, yet.

amorousf00p 8y ago

Whenever I see some shit like 'thanks for sharing' or 'noted' I want to kill someone. These are cautionary tales: ignore at your leisure.

ghrifter 8y ago
Holy shit dude, what next gonna get mad at emoji posting? Too bad I cant emoji spam on HN
sctb 8y ago
No matter how you feel, posting like this will get your account banned. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html

Narishma 8y ago

32KB was a ton of memory in the 70s.

aswanson 8y ago
Especially in 1970. That was a lot even for 1980.
deleted 8y ago
[deleted]

cylinder714 8y ago

Forgive me, but I'm struggling to understand how much useful work one could extract from a computer with only 32k of RAM. A microcontroller for an appliance, sure, but a mainframe? Could you tell us more about the work you were doing?

TylerE 8y ago
Oblig NASA factoid: The guidance computer on Apollo that got as to the moon had 4096 bytes of RAM and about 72K of ROM.
- cylinder714 8y ago
  Whew, excellent point. That raises another question, though—how much computational work did that computer have to do? The real heavy lifting was performed by big NASA mainframes on Earth, right?
  - cbm-vic-20 8y ago
    The Apollo computer did things like control rocket burns, provide navigational information, etc. More information http://nassp.sourceforge.net/wiki/Guidance_and_Control_System http://nassp.sourceforge.net/wiki/Guidance_and_Control_Syste... The source is on Github, too, for example: https://github.com/chrislgarry/Apollo-11/blob/master/Luminary099/BURN_BABY_BURN--MASTER_IGNITION_ROUTINE.agc https://github.com/chrislgarry/Apollo-11/blob/master/Luminar...
cylinder714 8y ago
(An aside: do terms like "mainframe" and "microcomputer" have any meaning any more, when a Raspberry Pi Zero has orders of magnitude greater RAM and power than a '70s piece of "big iron"?)
- joshAg 8y ago
  Yes. Mainframes still exist. IBM still sells them, and you can do things like hotswap CPUs and RAM or setup an geographically distributed HA cluster that can swap which mainframe the VMs or databases are "running" on without dropping connections, requests, or other interruptions. https://en.wikipedia.org/wiki/IBM_Z https://en.wikipedia.org/wiki/IBM_Z

cptnapalm 8y ago

Ooo! I have a question! Where do I learn more about overlays? The BSD 2.11 code I've read has comments about overlays, but I have no idea where to learn more about how to understand the topic. I came across it while I was seeing if I could get newlib to compile for the PDP-11.

monocasa 8y ago
Game consoles supported the concept a whole lot longer than other domains. ROM bank switching can be thought of as overlay loading, and beyond that most consoles supported overlays up until 360/PS3. The Nintendo DS cartridge format natively supported overlays for instance.
sehugg 8y ago
You could look at some old Turbo Pascal articles (though don't know how applicable it is to other systems): http://www.boyet.com/articles/publishedarticles/theslithytove.html http://www.boyet.com/articles/publishedarticles/theslithytov...
ddingus 8y ago
https://www.google.com/amp/s/www.vox.com/platform/amp/policy-and-politics/2018/7/16/17578548/voxcare-national-guideline-clearinghouse https://www.google.com/amp/s/www.vox.com/platform/amp/policy...
- ddingus 8y ago
  Dammit. Wrong link. Here is the correct one: https://www.elsevier.com/books/linkers-and-loaders/levine/978-0-08-051031-6 https://www.elsevier.com/books/linkers-and-loaders/levine/97...
  - cptnapalm 8y ago
    Was wondering about that initial link. Thank you for returning with the correction.
    - 8y ago