[sf-lug] PC with only 4 GiB of installed RAM (was the most recent: "some notes..."

[Michael Paoli]

> From: aaronco36 <aaronco36 at SDF.ORG>
> Subject: [sf-lug] PC with only 4 GB of installed RAM (was the most  
> recent: "some notes..."
> Date: Tue, 5 Jan 2021 01:32:40 +0000 (UTC)

> Quoting <me> from [1]:
>> If I heard this correctly, Victor mentioned that he was using
>> Windows 10, Oracle Virtualbox and Lubuntu under Virtualbox on
>> a [desktop?] PC with 4 GB of RAM. ...

<cough, cough> "only" 4 GiB of RAM.  Heh.

$ cat /etc/debian_version && uname -m && head -n 1 /proc/meminfo
10.7
x86_64
MemTotal:         131296 kB
$

Whippersnappers!  ;-)

Back in my starving student days, to get extra storage, since
I didn't have the 25 cents to spare in my meager budget to buy 100
new punch cards (each of which only had 12 rows x 80 columns - so
960 bits, or 120 bytes per card ... 12,000 bytes for your hard
earned quarter (or 2 bits, or 6,000 bytes per bit, just to make
things really confusing by mixing monetary and data units).
But you only got all those bytes if it was in binary - it was
generally encoded with only one byte per column - punching the cards
in binary made for quite flimsy punched cards - more prone to jamming
and the like - and got highly flimsy if they were 100% (all 960 bits)
punched.  So, at more customary 80 bytes per card, 25 cents per 8,000 bytes,
or 32,000 bytes for $1.00 USD.  But that wasn't RAM, that was just
your punched cards.  Ah, but I didn't have budget for that ... so instead
dove into the card recycling bins ... then off to the card sorter ...
and would sort the cards column by column - you couldn't sort by all
letters and/or digits on a single column at once, as the card sorter
only had, I think it was 14 or 15 output slots.  You could set it
for A-L, M-Z, or 0-9, and a column number, and would sort cards into the
first 13 or 10 slots, with everything else in the "other" slot.  So, e.g.
sorting the first 10 columns by alpha would require 20 passes ...
and you have to do them and stack them in the right order ... or you don't
end up with the correct sort at the end.  And you thought the sequencing
for manual duplexing on your printing was a bit tricky.
Anyway, I'd sort to identify blank columns ...
until I got 40 of 'em, from either end.  I'd also try from both ends.
Any cards with 40 blank columns from either end, I'd save.  I'd also
sort and separate out any that were completely blank.  The remainder
went back to the recycle bin.
And then early in my card deck, I'd put a special instruction card,
that essentially said that for all the following cards, only read
through column 40.
The less than half punched cards also doubled as my supply for
index cards - which of course I also didn't have budget for.

So, let's see ... 4 GiB ... as 80 column cards, 1 byte per column,
0.007" thick per card ...
$ echo '4*1024*1024*1024/80*0.007/12/5280' | bc -l
5.93133898989898989898
$
That would be a stack of cards nearly 6 miles high.
At the "cheap" student rate from the card vending machine of 25 cents per
100 cards ...
$ echo '4*1024*1024*1024/80/100*.25' | bc -l
134217.72800000000000000000
$
that would be over $134,000,00 USD for that stack of cards.
$ echo '4*1024*1024*1024/80/100' | bc -l
536870.91200000000000000000
$
Would have to feed that card vending machine over half a million quarters.
What's that RAM cost you on a Raspberry Pi now?

Let's see, that stack of cards would weigh ...
0.007" ... about 37.5 lb. card stock ...,
so about 37.5 lb. for 17" x 22" sheet x 500 sheets,
punch card ... 7 3/8 " x 3 1/4" ... so ...
$ echo '37.5/(500*17*22)*4*1024*1024*1024/80*(7+3/8)*(3+1/4)' | bc -l
258050.62844919786089375324
$ echo '37.5/(500*17*22)*4*1024*1024*1024/80*(7+3/8)*(3+1/4)/2000' | bc -l
129.02531422459893044687
$
So ... bit over a quarter million pounds,
or slightly over 128 tons.

Well, maybe a wee bit less after we count the bits that were punched out
(nice, annoying free supply of "confetti"), and the rounded and cut
corners (not required, but most cards had 'em - especially the one
corner cut at an angle so one could orient the cards).

"Only 4 GiB".

Maybe I ought also compute it for punch paper tape ... probably fair
bit lighter and cheaper, but not as durable, and not so easy to edit
(rearrange / replace cards) ... stack?  Could compute it for fan-fold,
or roll(s) ... what would be the typical max roll size/length?
"Of course" if you dropped and spilled your boxes of card(s), and hadn't
done your diagonal line markings and such along the side edges ...
But hey, cosmic ray ain't gonna knock one 'o those holes out for you.

Ah, ... but then there's the non-volatile storage ...
like 1 TiB on a microSDHC/UC compare that to the punch cards and
paper tape of about 4 decades ago.  And, think how that will
be comparatively dwarfed by the technology of 4 decades from now.