[ih] booting linux on a 4004

[Brian E Carpenter]

Jack,

> We now have the luxury of much more powerful hardware, 
> costing a tiny fraction of what a similar system might have cost in the 
> Arpanet era.   How did hardware and software engineering change over 
> that time?

I think that needs a book-length email to to answer properly :-).

If you want a short answer: then, it was possible for a human being to completely understand an operating system. Today, this is utterly impossible and the most you can expect to understand completely is code you have worked on plus the APIs it uses.

As an aside, but related to some of what John wrote, in 1973 Unix certainly wasn't ready for real time usage. At least, that was my opinion based on what Ritchie told me 51 years ago... https://www.cs.auckland.ac.nz/~brian/LetterFromRitchie.pdf

Regards
    Brian Carpenter

On 30-Sep-24 06:16, Jack Haverty via Internet-history wrote:
> On 9/29/24 08:58, Dave Taht via Internet-history wrote:
>> See:
>>
>> https://dmitry.gr/?r=05.Projects&proj=35.%20Linux4004
>>
>> While a neat hack and not directly relevant to ih, it sparked curiosity in
>> me as to the characteristics of the underlying architectures arpanet was
>> implemented on.
>>
>>
> 
> For anyone interested in the "underlying architectures arpanet was
> implemented on", I suggest looking at:
> 
> https://walden-family.com/bbn/imp-code.pdf
> 
> Dave Walden was one of the original Arpanet programmers.  He literally
> wrote the code.  This paper describes how the Arpanet software and
> hardware were created.  Part 2 of his paper describes more recent
> (2010s) work to resurrect the original IMP code and get it running again
> to create the original 4-node Arpanet network as it was in 1970.   The
> code is publicly available - so anyone can look at it, and even get it
> running again on your own modern hardware. Check out the rest of the
> walden-family website.
> 
> When Arpanet was being constructed, microprocessors such as the Intel
> 4004 did not yet exist.   Neither did Unix, the precursor to Linux.
> Computers were quite different - only one processor, no cores, threads,
> or such.  Lots of boards, each containing a few logic gates,
> interconnected by wires.   Logic operated at speeds of perhaps a
> Megahertz, rather than Gigahertz.  Memory was scarce, measured in
> Kilobytes, rather than Gigabytes.   Communication circuits came in
> Kilobits per second, not Gigabits.  Persistent storage (disks, drums)
> were acquired in Megabytes, not Terabytes. Everything also cost a lot
> more than today.
> 
> Computing engineering was quite different in 1969 from today.  Every
> resource was scarce and expensive.  Much effort went towards efficiency,
> getting every bit of work out of the available hardware.  As technology
> advanced and the Arpanet evolved into the Internet, I often wonder how
> the attitudes and approaches to computing implementations changed over
> that history.  We now have the luxury of much more powerful hardware,
> costing a tiny fraction of what a similar system might have cost in the
> Arpanet era.   How did hardware and software engineering change over
> that time?
> 
> Curiously, my multi-core desktop machine today, with its gigabytes of
> memory, terabytes of storage, and gigabits/second network, running the
> Ubuntu version of Linux, takes longer to "boot up" and be ready to work
> for me than the PDP-10 did, back when I used that machine on the Arpanet
> in the 1970s.   I sometimes wonder what it's doing while executing those
> trillions of instructions to boot up.
> 
> Jack Haverty
> 
>