Who has the slowest computer on the forum?

[VERAULT]

Any idea of the clock speed / bit width ?

The only information I can find online about it is this:
"Speed of calculations on the Wang 700 is sensational: 300 microseconds for + and -, 3.0 milliseconds for X; and 3.5 milliseconds for ÷."

 

[silcreval]

The only information I can find online about it is this:
"Speed of calculations on the Wang 700 is sensational: 300 microseconds for + and -, 3.0 milliseconds for X; and 3.5 milliseconds for ÷."

33 1/3 multiplications per second. Nice.

 

[Kelly Gray]

I have an Epson HX-20. 8 bit 6301 CPU clocked at 613KHz

 

[Chuck(G)]

Again, clock speed does not correlate to speed in many cases. Benchmarks or it's just speculation.

 

[Bruce Tomlin]

Anyone with an 1802 can set the clock speed to zero because it is completely static. You can't go any slower than that. I'm sure a few other CMOS CPUs are static, but the 1802 is famous for it.

 

[wrljet]

The NMOS Z80 is semi-static by design, and thus will not retain its state if the clock is left low for very long.
The datasheet spec is 2000ns, but my experiments show it to be several seconds.
It can be stopped with the clock high.

 

[Chuck(G)]

I believe that the Intersil 6100 was popular with the telemetry people for a time. CMOS, with retention at 0 MHz clock. So, if anyone has one of the "CMOS PDP-8" setups with CMOS SRAM, I'd like to know how slowly you've tried to run it.

 

[twolazy]

Would you consider a Speak and Spell a computer? TMS1000 based, clocked at a whopping 400KHz

 

[g4ugm]

Again, clock speed does not correlate to speed in many cases. Benchmarks or it's just speculation.

Well it runs in exactly the same way as the full size Baby does so as noted here :-

Manchester Baby Computer

The first program to run successfully, on June 21st 1948, was to determine the highest factor of a number. The number chosen was quite small, but within days they had built up to trying the program on 2 to the power18, and the correct answer was found in 52 minutes, involving about 2.1 million instructions with about 3½ million store accesses.

so slow, but still faster than I could manage...

 

[Gary C]

What about a Kent computing relay

Analog control using bellows, flappers and nozzles. Can 'compute' Proportional, Integral & derivative terms from a measured value and produce an output.

So slow you can see it move

 

[Bob-O-Rama]

TI-95, it is ( vaguely ) turing complete, can manipulate and print text, has ROM modules, and read / write mag strip storage for data and code, so its a computer. Its clock is ~460Khz with an idle mode that divides that by 4, which form its state cycle clock. However in the TI-59 an instruction cycle consists of 16 state cycles. So it can executes instructions at 29K ips when calculating. That's pretty dang slow.

 

[Chuck(G)]

Analog control using bellows, flappers and nozzles. Can 'compute' Proportional, Integral & derivative terms from a measured value and produce an output.

I used to work on that sort of thing during my college summers as an instrumentation tech in a steel mill. Pneumatic, 3-15 PSI signalling, lots of fascinating gadgets, all hooked together with 1/4" copper tubing with brass fittings. Another one is the Askania hydrostatic systems--high-pressure oil and jetpipes...

 

[Gary C]

I used to work on that sort of thing during my college summers as an instrumentation tech in a steel mill. Pneumatic, 3-15 PSI signalling, lots of fascinating gadgets, all hooked together with 1/4" copper tubing with brass fittings. Another one is the Askania hydrostatic systems--high-pressure oil and jetpipes...

Yes, Fisher controls & Kent systems. 3-15 PSI. We even had pneumatic chart recorders. I started as an instrument tech too but in a coal power station. Probably similar to a steel mill in many ways, probably cooler though.

 

[VERAULT]

I started as an instrument tech too but in a coal power station.

I would love to tour a COAL power station.. Modern or old operational. I have been around nuclear reactors (submarine control stations, and test reactor facilities [Connecticut used to have a small one on the CT river but it was decommissioned 10 or 15 years ago] and I have been inside smaller hydro-electric facilities. There are a bunch around where I live.. Two 10 minutes from my home.) but never a coal plant. I have to assume the stoking and hopper feeders are all automated but still it would be amazing to witness.

This one down the road for instance was built in the early 1920's. Here is a photo of it being built. The turbines are also reversed to pump water up the hill behind it to flood the valley which became Connecticuts largest lake. Candlewood lake. The lake has estuaries that feed it naturally and the runoff comes down that large diameter pipe in the back to power the turbines. Still running today with modern turbines.

Sorry didnt mean to hijack the conversation. Just really interested in these things.

 

[rmay635703]

I have a very old very narrow/wide programmable scientific calculator with its original brown plastic case. (Might be a 40 character display)

It runs low kHz for obvious reasons, likely slower than most machines listed so far.

 

[Chuck(G)]

Yes, Fisher controls & Kent systems. 3-15 PSI. We even had pneumatic chart recorders. I started as an instrument tech too but in a coal power station. Probably similar to a steel mill in many ways, probably cooler though.

The pneumatic chart recorders at my work were mostly Moore models. Chart recorders/controllers were mostly L&N or Honeywell/Brown. At the time, one of the jobs was to replace the old Weston standard cells with line-powered electronic references. Still lots of old Micromax clamp-galvanometer recorders, though. Used a big 1.5V carbon cell (National Union?); a few were even clockwork driven.
All of the recorder amplifiers used mechanical choppers; a few were transistorized, but most were vacuum-tube. There was a distrust of semiconductor technology back then.

 

[Gary C]

They have knocked down my old station

Really really sad day. Not even been back since because I don't want to see it not there. My dad worked there too and it was a feature of my life from being a small child. Amazing and really dirty place

Worse still, the A station was knocked down in the 80's two days before it was to be made a listed building. Now that place was special, built in 1930 with teak parquet floors and brass everywhere.

Few people care about industrial heritage until its >100 years old and by then its probably already been scrapped.

 

[VERAULT]

They have knocked down my old station

Really really sad day. Not even been back since because I don't want to see it not there. My dad worked there too and it was a feature of my life from being a small child. Amazing and really dirty place

Worse still, the A station was knocked down in the 80's two days before it was to be made a listed building. Now that place was special, built in 1930 with teak parquet floors and brass everywhere.

Few people care about industrial heritage until its >100 years old and by then its probably already been scrapped.

Whenever I visit "old stomping grounds" I get similar feelings. Certain places now are un-recognizable. For instance when I was young there was a very large Drive in movie theater a town over from where I grew up. You could see it from quite a distance away, but it was not an eyesore. Its all been leveled for condominiums. And it saddens me every time I drive by.

Constant change erasing the past.