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ooh, check it out! The operator console from an IBM Model 705 mainframe!
who needs woodgrain when you can just have wood?
no PCB inside, just a lot of individual components and a huge bundle of wires
I love these toggle switches.
They feel like they're off an electric organ.
and so many buttons, and what do they mean?
"half multiple step"?
It's on ebay, bidding is currently up to 100$
Here's a picture of the full console this would be part of.
The IBM 705 was developed in 1954, as an update of the 702 with increased memory capacity.
The 702 had 2000-1000 characters of Williams tubes memory, the 705 could have 20,000, 40,000, or 80,000 characters in core memory.
Williams tubes are a neat type of early memory, where you display the RAM as a series of dots on a CRT, then a thin sheet of metal in front of the tube is used to read the dots back off. Here's one from a IBM 701
The way the sheet works is interesting. It's not like you had a bunch of sensors for each individual dot, it's just one sheet.
But the way you read memory is by writing to it... yeah.
so you draw a bunch of dots on the screen, representing which bits are on.
This causes redistribution of the electrons in the phosphor coating of the tube, and a positive charge everywhere dots were drawn
to read a location back out, you write to it, setting it high.
If the dot was already drawn, the charge goes positive->positive, and there's no current induced in the metal plate.
But if that dot wasn't drawn (so it's a zero), it goes negative->positive, creating a current
that small current is amplified and transmitted back out, and now you've read your bit.
You do have to refresh this memory, a lot.
The phosphors naturally fade to black, but there'd be dedicated circuits in the computer that do the refreshing of the tubes while the main CPU was doing other things.
(It's very similar to how DRAM controllers work today)
one interesting thing about how the write is destructive (you write a 1 to read out a 1 or a 0, so if it was a zero, you just flipped it) is that the way you'd then set it back to zero would be to write NEXT to the location.
because of how the bits are stored as bits of positive charge near spots of negative charge (where the dislodged electrons landed), to turn a bit back towards neutral, you just drew near it, causing the newly drawn spot to become positive and the original spot negative/neutral
an easy way to do this (for timing reasons) was to draw to the spot while moving the beam, producing a dash.
So in that picture above of the dots, the dots are 1s, and the dashes are 0s.
It's like a weird morse-code memory bank!
These tubes were developed at the University of Manchester, while building the Manchester Baby computer in 1948.
The Manchester Baby was a testbed to confirm confirm the tubes could be used for the Manchester Mark 1
So while the IBM 702 used Williams tubes, the IBM 705 (which this control panel comes from) switched to core memory.
Core memory is really neat. It uses tiny little donut-shaped magnets to store bits. Each one has three wires going through it: the horizontal drive wire, the vertical drive wire, and a sense wire (there's also sometimes an inhibit wire, but later that was merged with sense)
The way it works is that running a current through a coil will cause the magnetic field to be changed to clockwise or counterclockwise, at a certain current.
By running a vertical line at half that current, and a horizontal line at half that current, only the one coil selected will see the full current, and only it'll be affected.
Depending on the direction of the current, it'll flip to either clockwise or counterclockwise
Because the magnets are little circles, there's no magnetic pole to the magnet, the magnetic flux is almost entirely contained within the magnet. So you can put two of them very close to each other without them affecting each other, allowing denser memory
so, you can make the magnets clockwise or counterclockwise. Great. But how do you read it?
Well, the same way you write it! You just set them to clockwise or counterclockwise.
because similar to how an electrical current going through a coil induces a magnetic field, the changing magnetic field induces a current in a wire: The sense wire.
So by writing to a position, you also get a signal out the sense wire... if the bit flipped.
If that coil was clockwise and you set it to counterclockwise, there'll be a small current in the sense wire.
If it was clockwise and you set it to counterclockwise, no current.
and just like Williams tube memory, the read-out is destructive (half the time).
If it was a 1 and you wrote a 0, or vice versa, you just flipped it, and now you have to flip it back.
an interesting thing about core memory is that while there were attempts to build machinery that could automatically produce it, nearly all core memory ended up being made by hand.
It's surprisingly tricky to automate making this sort of thing.
But you know what seemingly unrelated thing is basically the same, and has been done manually by humans for, oh, 9000+ years?

also I was totally wrong about that time period. that was the oldest old world woven textiles.
There's some woven textiles in Peru dated to 11,000-12,000 years ago.
and there's some suggestion (imprints, but no surviving textiles) that weaving was used at the Dolní Věstonice site in the Czech Republi, and that site is 29,000 years old.
So weaving is Quite Old, to say the least.
But yeah. Core memory was heavily used on computers from the mid-50s to mid-70s.
It didn't really start falling out of use until dynamic RAM got cheap enough to replace it, in 1970.
the fun thing about how core memory works is that you access each bit by a vertical and horizontal location, then you can stack a bunch of these core memory planes to get more depth.
In other words, you need an X, a Y, and a Z... it's a 3D cube of memory!
If you count out the driver lines on that core memory module, it's 32 by 32, or 1024 bits.
So that's 128 bytes, making it ALMOST enough to store this tweet (in 8-bit ASCII or UTF-8).

This tweet takes 225 bytes, or 1800 bits.
BTW, the IBM 705 was one of the last computers IBM made prior to transistorizing, so it's a vacuum-tube based computer.

They changed the names of the computers in the series to be 4 digits instead of 3, after switching to transistors.
Confusingly, the transistorized version of the 705 was the 7080, not the 7050.
Apparently IBM wasn't planning to build a transistorized version of the 705, expecting the IBM 7070 to be the successor to the IBM 650 and 705, but it ended up not being compatible with either
and since it was especially not compatible with the 705, requiring major changes to any 705 code, IBM instead built the 7080, which could be configured to boot up in a 705-compatible mode, then software could opt-in to taking advantage of the 7080 features as needed.
making it somewhat similar to how the PCs used to (and sometimes still do) start up in 16-bit mode for compatibility with old DOS programs, then have to switch into 32bit or 64bit mode to run Windows/Linux/whatever.
the pictures on the IBM 700-series wikipedia article are great, btw.

Like there's this one of an IBM 704 mainframe at NACA in 1957, which is like "wow, that's a big computer!", and the operator in the foreground is loading punchcards into it.
but then there's this (undated) picture of a IBM 702 at the US Army's Aberdeen Proving Ground in Maryland, and you're like "OH RIGHT, computers used to be FUCKING HUGE"
There's also this picture of the operator panel for an IBM 701.
Check out those little lights (lamps, not LEDs!). They wired one up to each bit in the registers of the computer... you can literally see what the computer is doing by looking at the lights.
todo: build a physical debugger for a modern CPU, using this style.
an X86-64 CPU has 16 primary 64bit registers, and then another 16 128-bit XMM registers, and then 8 80-bit FPU registers, then 22 bits for the flag, 64bits for the instruction pointer... that's only like... 3798 separate bulbs?
although there's also a bunch of extensions to the base set of registers. Like if your CPU has AVX-512 support, you've now got up to 32 512-bit registers, so that's another 16,384 lamps.
let's see here.
No AVX-512 but I do have AVX, so that means my SIMD registers are 256-bits wide, and I have 16 of them.
So that's only 4096 bulbs.
also I was slightly wrong: The 16 128-bit XMM registers of x86-64 (which started as 8 128-bit registers from SSE)? they overlap with the AVX/AVX-512 registers.
So I was counting them twice.
basically each of SSE/x86-64/AVX/AVX-512 expands the same register file, either making it wider (128 bits each to 256 bits each to 512 bits each) or adding more (from 8->16->32).
But the same registers are involved.
this great diagram for all the registers possibly available in the x86-64 instruction set is a great way to show how registers are built on each other, and also shows WOW AM I UNDERCOUNTING A LOT
like I forgot about the segment registers.
"but foone, x86-64 isn't a segmented architecture! we haven't done that since what, the launch of the 386 in 1985?"
very important we keep around those 96 bits worth of segmentation information just in case someone needs to run Alley Cat on their core i7.
anyway enough RANDOM COMPUTING FACTS. I should do something else other than blabber about a neat thing I found on ebay.
but I will say that if you want to look at random neat things, "operator console" is a fun search term to use on ebay.
You'll get old computers like this and CNC machines and they all look LOVELY.
and this! A MovieVideo-SCS Console.
I don't know what that is, apparently it has something to do with movies?
But I want it.
oh god I went off ebay and now I know what my next PC is going to look like
That's the Mission Console from the Government Flying Service Jetstream 41, which is a set of two planes that used to be operated by the Hong Kong Government Flying Service, for search-and-rescue reasons.
my favorite detail is this bit.
They clearly designed it with some big important Industrial Aviation Connector and then a bunch of years later went "screw it, someone build us a USB-to-Complicated-Thing adapter so we can use a logitech trackman"
The Spohn & Burkhardt Operator Console SV1C

I'm not sure what industries this was designed for, other than Star Trek Cosplay?
ahh. complex machines and cranes in ports and industrial facilities.
hang on I gotta do some job research
oh neat. check out this PBX system, @gewt!
ooh, more CNC. I always love CNC panels.
I saw this one and was like "ooh, is that a 5.25" floppy drive!?"
that's the keyboard.
ooh, control panels ON THE GO! with the IK2 Console Box Remote Belt
this is neat.
it's a Dahlgren Wizzard II Engraver.
Check out that keyboard and TINY CRT
Another picture with the keyboard a bit more visible.
here's a tiny picture that shows it in use.
ooh, an open one!
I wonder what this is built on?
and that same one with the screen showing something.
the reason I'm interested in "what it's built on" is because I suspect it might be a familiar 8-bit computer...

See, Dahlgren apparently started with their System One, a computer controlled engraving machine, and that computer right there? It's a TRS-80!
that's from this article, and it mentions that ad was from The Engravers Journal in July/August 1980.
So these engraving machines from Dahlgren were made in the 80s/90s, and I bet Tandy would have been willing to license them the TRS-80 design to build on.
want more fonts for your Wizzard?
They come on EEPROMs!
oh hey, this one has a good picture of the keyboard.
I really like the COMPUTE button.
Not enough computers have that button.
OK, there's a picture of the screen in use.
Notice that odd lowercase l? it kinda looks tilted, or like a thin backwards s.
So, that's NOT a trs-80, at least not an unmodified one.
It didn't have lowercase out of the box, and the mods that add it don't look like this.
so I'm gonna guess if it's not just a licensed TRS-80 system, they probably built their own basic Z80 system. There were certainly tons of them around, and it'd let them reuse (some of) their code they wrote for the TRS-80
it looks to be a 16-line by 32-column display.
Which does match the lower-resolution mode of the TRS-80, but might just be using the same generic CRT controller
BTW if you're looking for TRS-80 fonts, there's a good compilation of them here:
See that cartridge on the right side?
it comes with a whole stack of cartridges of fonts.
The manual has the Wizzard. I like 'em
but yeah... there's one on ebay. I kinda want to tear it down and figure out how it works, but I'm not 1,500 CanadaDollars worth of curious
picclick archived this picture of an ebay auction for someone who would do preventative servicing on your Dahlgren Surgrave Wizzard, but sadly the original listing is long gone. I was thinking of asking them to tell me what it's built on.
oh hey, I found them.
They haven't updated their site since 2009, although it looks older given the september 11th american flag GIF.
and hey, they're local!

time to email them and see if I can come over and look at all their shit
just remember
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