Hello and welcome to Japan, the land of a
thousand shrines, which exudes a fascinating combination of tradition and
modernity. The land of advanced technology that gave us such electronic
wonders as the handheld electronic calculator, the Walkman, the LCD
electronic watch, the confusing train ticket machine, the incredible ticket gate
machine, the cute but somewhat useless robots, and not to forget the super
complicated computerized toilet and the dancing
plastic food displays. So Japan seems to be at the forefront when it comes to
electronic gizmos. But it was not always the case. Today, I have been invited to
take a look at one of Japan's earliest commercial computers, the FACOM 128B. A machine developed by Fujitsu in 1958. Amazingly enough it's not based on
transistors, not even tubes, but on relays. And even more amazingly it still works
as of today. But wait, did I just say relay computer, in 1958? What gives? Even for the time, making a relay computer seems completely anachronistic. This is a whole
15 years after the ENIAC, considered to be one of the first tube based digital computers,
developed in the 1940s. In this timeline it appears sandwiched between the IBM
650 and the IBM 709, two large and rather evolved tube based machines. And our IBM
1401, introduced in 1959 would already feature a fully transistorized design. The era of relay computers was
contemporary to the Eniac. George Stibitz at Bell Labs was the first one to
realize that the same relays used in telephone installations could be used to
build computers built on the binary principle. He demonstrated the first
relay based computer in 1939. It was quickly followed by larger and larger
models for the military. The Bell Labs machine II, which already includes
floating-point hardware, dates from 1943. Meanwhile in Germany computer pioneer
Konrad Zuse demonstrated the relay based Zuse 3 as early as 1941 and the Zuse 4
in 1944. Then a generation of immense relay behemoths were built to support
the war effort, including the Bell Labs models 3, 4 and 5. But most famous is the
1944 Harvard Mark 1, although its main calculating elements are
electromechanical counters, not relays. You can still see a portion of the
Harvard Mark I in Boston. The 1947 Harvard Mark II was equally gigantic, and replaced
the counters with relays, making it a proper relay computer and much faster. Finally
one of my favorite has got to be the space age looking IBM Selectively Sequence
Electronic Calculator, which uses a combination of tubes and some 20,000
relays. But of course the ENIAC showed to the skeptics that a viable tube based
computer could work at least 100 times faster, and the rest was history. The
electronic tubes took over, and relay computers were quickly forgotten. After the disastrous end of the war, the
battered Japanese nation was in the process of rebuilding and eager to
retrace the early steps of computing. A small-scale replica of the ENIAC logic
was demonstrated at the Osaka University in 1950, followed by a larger machine
using the EDSAC instruction set Meanwhile, ETL a famed research lab
funded by the powerful MITI government agency, designed a huge relay computer
with 20,000 relays, this time taking aim at the Harvard Mark II. Fujitsu at the
time the Fuji Tsushinki Manufacturing Company, was the leading Japanese
provider of relay based telephone equipment.
It was contracted to build a huge relay computer from MITI. Following this MITI
sponsored effort, Dr. Toshio Ikeda, who would later rise all the way to become
the managing director of the entire Fujitsu company, decided to design a
commercially viable relay computer. He called it the Fuji Automatic Computer, or
FACOM 100. An improved revision the 128A was developed in 1956, and the final
design iteration was the 128B in 1958 So it had taken a long time but the
FACOM 128 was Japan's first realay computer that was not merely a
laboratory demonstration, but a true commercial product. I took advantage of a
recent vacation in Japan to see it firsthand. I dragged my wife along, but
fortunately the Shinkansen rides are always a treat. That's how we ended up at
the foot of Mount Fuji, in Numazu, where everything is Mount Fuji themed,
including your foldable chopstick holder Numazu is the site of the Fujitsu
factory that used to produce the firm's famous Japanese IBM-compatible
mainframes This FACOM 128B was built in 1959. Our visit
was hosted by Mr. Yoshio Takahashi who facilitated the translation. English was
a bit choppy, and my Japanese is non-existent, so I will mostly do a
voice-over for the rest of this video This particular machine comes from the
Nihon University in Tokyo, Japan's largest University, where it
remained in service for 15 years. And we all need to give a hand to this shy
gentleman Mr. Tadao Hamada, the lead restorer and the hero of this
restoration effort. This machine was predominantly used for scientific
calculations. Mr. Takahashi explains that it was used at the university for
the design of this Japanese turboprop plane, to model the flight effects of
losing one engine. It's done with relays, lots and lots of relays. Mr. Hamada gives us a quick orientation of the main elements.
The CPU is contained in the racks in front of us, we'll see how the memory is
hidden behind in a minute. It has a very impressive central console. It is also
well endowed with multiple tape readers and punchers with a very large bit width.
The tapes are used for both programming and data. The 128B also has banks of
read-only memory. The read only memory is simply implemented with peg contacts and
perforated cards. It is primarily intended for special function look-up
tables and subroutines. The system is completed by an output printer. As you'll
see its principle of operation is directly inspired from the older IBM
moving bar printers found in the early tabulating machines, but it prints
impressively crisps outputs. And it's on! Okay, we're on. I believe
the first demonstration is going to be three plus three.
Now as you can tell it's not entirely obvious how you would do such a simple
thing faced with this sea of buttons and lights. Well the first try did not work quite as
expected, which gives us a chance to admire the pale blue front panel. The
left keypad is used to input numbers. Numbers are floating-point, with 8 digits
in the mantissa and 2 in the exponent. The exponent varies from minus 19 to
plus 19, so the machine is more like a programmable scientific calculator
running natively in floating-point, Like most of the relay machines of the time.
We'll discuss later how single digits are represented in binary using seven
bits, while sign is two bits, leading to very wide word size of 69 bits, also typical
of relay machines of the time. The right panel is for the instructions. It starts
with 3 memory addresses fields of three-digit each, 2 for the operand and 1
for the result. The two first address fields go from 0 to 299 and the third
address is from 0 to 199. Now, on the right of the keyboard, is the opcode part
of the instruction. All set and done, I count about 70 bit of width
give or take a few. How many bits? 72 bits for instruction. 72 bits per instruction? Wow, that's a lot
of bits. Ok, this was just an opcode error. We are all sorted out. We are about to do 3
plus 3, watch closely 3 plus 3. Let's see how to decipher the
result of the blinkenlight panel. Once again, the bones of the machine show
through. We easily recognize our 8 digit mantissa and 2 digit exponent, but the
digits are displayed in a peculiar way. This is due to the internal bi-quinary
representation. Each digit is encoded using 7 bits like so: there are five bits
encoding the quinary part, 0 to 4, and 2 bits encoding the binary part, 0 or 5.
The result is obtained by summing the quinary and the binary parts. In our case
bit 5 is on and bit 1 is on So this is 5 plus 1: this is a 6 The main advantage of bi-quinary is the
ease of error checking. Note that always one, and only one bit has to be present
in the binary and quinary part of the coding. It is very easy to find a relay that has
stuck or not made contact, in which case either zero or two or more bits
will be set in a section. Since temporary contact problems are frequent in relays,
bi-quinary encoding was well worth the extra
coding bits, and an accepted standard and coding scheme, ever since the Bell
Labs II relay machine. Takahashi-san is showing us the rack responsible for
addition and subtraction This rack is the hardware for multiply, divide and square root. These earlier
relay machines are really deceptive most of them had advanced floating-point
hardware and are much more capable than you'd think So that's two. There you go: one point
four one four. Yes, that's it! Impressive. Can you do it you do it again? And here
you go: about one second for a square root It's not that bad actually, about what a
pocket calculator from the late 1970s would do. Clunk. Two seconds. Very impressive. But
there is more hidden behind the first row of racks past the power supply. This is
where the many memory racks hide Oh that's awesome. You can see the crossbars
on it. The memory implementation is another example of reusing
electromechanical switching components of the time. These units are actually
telephone crossbar switches. Originally crossbars were just that: two alignments
of contact bars crossing each other in the matrix arrangement. In order to
connect an input to an output, the telephone operator would just insert a
peg at the intersection of the bars, and establish the telephone circuit between
the caller and the receiver, for the duration of the call. The invention of
the automated crossbar in the 1930s was a major telephone switch advancement, a
co-invention of Swedish and Bell Labs engineers. A crossbar switch could
establish the contact using an electromagnet to actuate the bars, then
capture the contact for the duration of the call. One more relay would release
the contact at the end of the call. Essentially the crossbar is an
electro-mechanical matrix memory The FACOM 128B has 180 words of
memory. Assuming a 69 bit width, that would be about thirteen thousand bits. Thirteen thousand bits! The memory takes
a huge amount of space hidden at the back of the machine. There are two rows
of memory cabinets, and each row has crossbars
both in the front and in the back of the rack. Wow! And this brings us to the power supply.
There are two cabinets: the functional one here is actually a very well done
modern reproduction, while you can see the original decommissioned one just
behind. The machine is pulling 30 amps at 80 volts, so about 2.4 kilowatts. This was
much less than I expected. Our transistorized IBM 1401 is about 12
kilowatts. To put it in perspective, a single modern
19-inch rack from a Google or Facebook installation would be in the 25 kilowatt
range. It's a reproduction of the original. Here you have the older style switches. That means 1960. Where can you read that?
Oh okay, you have to be good in Japanese! Okay, we were just warming up. Now
we are going to solve a realistic math problem: a set of five linear equations. This will involve the inversion of a five by five
matrix. To program the machine we have the trusty paper tape. And it's not eight bits. This problem requires running a program loop, which in our case
is an actual perforated tape loop. The tape is 36 bits wide, so an instruction
takes two rows of perforated tape. One paper tape is used for the program and the second one is used to input the data. All right, I hope everyone is ready for
the big matrix inversion, here we go! Holy Molly! I didn't expect the
calculation to take so long. I kept it almost in its entirety, but you will be
forgiven if you skip ahead two minutes to the end result. So right now it's inverting the matrix,
doing matrix inversion? It's solving the problem using matrix inversion I suppose, calculating very hard. It's hard to film, everything's moving at the
same time! Hey, done. [Hamada-san] Input data. And the answer is down there. [Takahahsi-san] This uses the answer to do the same calculation and
find the difference. Oh, that's the error. That's the remaining error on the
matrix inversion, I get it. Congratulations! But what do you do when
something goes wrong. Hamada-san tells me it does not happen too often. Regular
maintenance is only every three month on average with the machine being demoed
almost every day. They change out only one relay a year. The wiring technique is exactly similar
to the one used in Fujitsu's contemporary telephone installations.
Notice that no connectors are used for the relays. Wires are soldered directly
to the leads which makes it quite challenging to swap out a relay. I also
like that they had preserved the original maintenance toolkit that came
with the machine. There would be just one successor to the FACOM 128B, a scaled
down model 138, and this was the end of the relay computer story. But this was
not the end of the FACOM line, quite the contrary, but rather the beginning. Collaborating with former IBM famed
designer Gene Amdhal, Fujitsu would go on to release a successful series of IBM
compatible computers under the FACOM name, that not only were compatible but
also looked very much like their IBM brethren. Eventually Fujitsu would emerge
as Japan's computer powerhouse and build some of the fastest computers in the
world. What to treat though to witness the first heroic steps of computer
engineering so well preserved. I hope you have enjoyed this marvelous machine as
much as I did. Many thanks to my hosts Takahashi and Hamada-san and also to
Samtec and Fujitsu that let me spend some geek time with no intention to
bring back any business whatsoever. Tsayonara!
And still controls the grid for Tepco.
Can it run Crysis?
Don't several of these super old computers still work (globally I mean)? Talk about planned obsolescence...
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What is that strip with the dots called ?
I want one. Perfect toy.
Go looking for that one relay that's broken somewhere in there makes for a happy few weeks of joy and excitement, oh yeah!
Legend says they even have working FAX
I want to go back and see this.
NGL, this makes me appreciate what I learned in Numerical Methods way back then. I'm wondering if it's open to the public. I want to see it in person so badly!