25 Oct. 2006
SETI League
PriUPS Project

Memories of Memory

Yesterday I indulged in a chronological reminiscence about bandwidth.  Today, I do the same with memory.  Unlike bandwidth, an emerging phenomenon of the 90s and the present, memory has been with me almost from the beginning of my nerdhood.  One of my first obsessions was building Morse Code keyers, which had very rudimentary memory since they needed to know a previous state of the dot or dash key to correctly form the Morse characters.  How much memory?  Two bits.  Doesn't really count, I guess.

1967 - 64 bits

What does count is my telephone dialer.  Using a surplus numeric keyboard from a keypunch machine, and (I think) RTL although it may have been TTL ICs by then, I made a dialer/redialer with a 64-bit memory chip, possibly the first ever sold commercially as a single IC.  Back then, probably around 1967, the radio call-in shows would take the first caller, not the hundredth or whatever.  No longer did I have to twist the springs on the ten-digit dial regulator mechanism to get in first.  Now I could lose every contest simply by pushing a button!

1969 - 500 bytes

My first personal computer!  If you remember that the first personal computer was introduced in the mid 70's, and names like Altair and IMSAI are bubbling in your brain, you're not wrong, but you weren't paying enough attention.  That's OK.  Very few people followed Hewlett Packard then, or knew that the very first personal computer, the 9100, had been out for almost a decade by the time the Apples and PETs came on the scene.  I bought its successor, the 9810, with my life's savings.  That was OK: It provided enough entertainment that I didn't need to see movies any more!  It came with 500 bytes of RAM.  I could have enhanced it to even 1000 or 2000 bytes, but at a dollar a byte, I would have also had to eschew food, a somewhat greater sacrifice than I had intended.

1974 - 16kilobytes

My HP 9825, the first of this new generation, and the one that taught me how to use the still-unappreciated HPL language.  The one that taught me about bubble memories, CRT monitors (which we proposed to build for a special government program), and which prevented an international incident.  Yes, its picture is in my wallet to this day.

1977 - 128kilobytes

I think you may be seeing a trend at this point, not just in increasing memory, but in increasing Hewlett-Packard model numbers.  We bought a 9845A for research into digital reverb.  While "Sensitive Guy" Tony was doing audio science, I was looking inside the computer at the 128K memory board and at the two empty sockets next to it.  I was also looking at the HP price list, showing that if we wanted to increase the memory to 256K, all we would need would be an additional $5200.  While this $.04 per byte was far less than the dollar-per-byte extravagance required to enhance the 9810, it was still vexatious.  Finding no special chips or mysterious construction techniques on the extant board, I came to the realization that I could design, obtain the parts for, and do a small production run of these boards for the price HP was asking for a single board.  A new business!  Somewhat later we  expanded our commercial offerings and offered an expansion board for the Commodore PET.

Also in 1977, we introduced a device unthinkable just a few years earlier.  Using 160 memory chips of 16kB each, we made the first "profanity delay" for broadcast use.  With a third of a megabyte of memory we could delay an audio signal long enough to stomp those nasty words into oblivion.

1979 - 512kilobytes

It wasn't long before HP came out with expanded boards for the 9845B and later the 9845C.  The machine maxed out at 1.5MB as I recall, with the largest memory card still at 512K.  But soon HP offered its next generation of computers, the 9826/9836 series.  These began life with 64K memory boards, which we quadruplicated as 256K "quarter pounders."

1980s - 1990s - Megabytes and More

As much fun as it will be for you to trace along with me the history of increasing memory sizes in each new HP computer, my personal memory is refusing to submit the precise details to my manipulative appendages, suggesting that maybe a quick summary would be more worthwhile.  The summary is:  At the beginning of the '80s, one could put together a computer with a megabyte of memory at ruinous cost.  By the end of the '80s, the cost was minimal, and many computers were beginning to have megabytes.  By the end of the '90s, a megabyte would buy you the ability to maybe boot your computer if you were still using an old operating system.  For anything newer you needed more.  A lot more.

2006 - The Common Gigabyte

And so we arrive at the present.  We all have PCs that only creep along with 256 megabytes of RAM.  We can buy the additional 256MB we should add with pocket change, but are too lazy to open the box.  And we are all awaiting the advent of Windows Vista, the first operating system that will demand a full gigabyte to expose all its features.  Which gigabyte will fit in the palm of your hand and cost not much more than a hundred dollars.

Better than Bandwidth

Was that a breathtaking journey or what?  Do you know how much space a gigabyte of memory for my first computer would take?  I don't either:  Let's figure it out...

500 bytes per board, which was about 8" by 4" inches and 1/2" thick.  Let's say it weighed half a pound.  That's 16 cubic inches of volume.  Let's multiply that by 1 billion / 500, which is 2 million.  So:  A million pounds filling a cube of 20+ feet on a side.  Hmmm - that's about twice the density of water, which doesn't sound too far off.  I'll have to find an old memory board and confirm that it doesn't float.

Comparing this ratio - two million to one in the period of less than 40 years - to yesterday's bandwidth comparison, we see that, if anything, memory capacity has increased even faster.  Wonder if it means anything.  Maybe, maybe not.  I'm going to continue this series, maybe as soon as tomorrow, although I did just take a photograph of the fish tank.

Richard Factor

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