OT Computer Memory (was OT but very useful...)
 

Larry wrote:
(Richard Casady) wrote in news:49c969b9.9397015
@news.east.earthlink.net:

Eight bits, one byte, per tube.


I'd love to know the physics behind how they did that. Dual triodes, such
as 12AX7, 12AT7, 12AU7, or even earlier 6SN7 were used as latching flip
flops, but they only stored one bit...0 or 1. To get 8 reliable levels
would be magic. They did use a neon counter tube that had multiple
cathodes. Perhaps that is the "tube" that did a byte.



[long nostalgic bit follows...]

Well, this was a slightly mixed memory, I'd say. the idea of 8 bit
collections called bytes came later, around the IBM 360 time frame.
Previous IBM incarnations like the 1401 used eight bits plus parity:
6 data, and two marker bits for laying out data fields - if you wanted
to add two 1000 decimal place numbers, no problem. Just lay down the
field length markers and issue ADD

But computer memories were kinda weird and wonderful.
There was quite a development effort into CRT memory storage:
allocate an X and Y value for each bit and point the electron beam at it
to set and to read it out. Hundreds or thousands of bits.
Trouble was the beam position drifted, which didn't help data integrity.

The serial computers used a nickel line for short term storage: you
pulsed an electromagnet at one end to set a pulse going for a '1' or no
pulse for '0' so a stream of pulses would run down the nickel wire at
the speed of sound to the sense coil at the other end, where the data
would turn round to the start coil and start over.
That was called magnetostriction.
Others used mercury delay lines. Or coil delays.

Some early boxes used nixie tubes, which were squat little vacuum tubes
with ten digits in a clock around the top. It was necessary to kick the
glow from electrode to electrode to count from 0 to 9.

But the giant leap from tape drives - first 200 bits per inch, then 650
bpi then 2200 bpi and fixed drum drives to disk drives made the
creation of operating systems much easier.
Before that time, there really were operators who would load up a
data tape or two and an application program and hit run.
Around 1956, the core memory was a wonderful step forward.
Little ol' ladies really did stitch up 4 kb memories from tiny ferrite
rings. Some of them were dunked in a tank of oil to keep the heat down.
Speeds went up fast, from 12 microsecond per cycle, to 4 us to
2 us, then 1.2us then semiconductor chips came along. A big commercial
machine might have 64kb, even 128kb.
This was a step back in one way: you could lose power on a core
computer and when it came up again, the code and data were still there
in core. Not so with solid state memory....

But I'll stop here....
Brian W

OT but very useful...
 

"Marc Heusser" d wrote in
message ...
In article lutions,
"Capt. JG" wrote:

I also just downloaded TideApp which is the TideTool equiv. for the
phone.
Nice.

There is also Tides.
Comparing with the official tide tables for Hamburg, Germany (at
www.bsh.de) though, both of them were off by quite a bit - Tides was
better but still too far off.

Marc

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I'll check it out!

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OT Computer Memory (was OT but very useful...)
 

Brian Whatcott wrote in news:rmBxl.21117
:

This was a step back in one way: you could lose power on a core
computer and when it came up again, the code and data were still there
in core. Not so with solid state memory....

But I'll stop here....
Brian W



A local Catholic church gave me a complete IBM Systems 32, including OS
and small business software for a small manufacturing firm. It had two
fixed drives, huge noisy ones; an 8" floppy drive that had a boot loader
on floppy and a large data cassette drive to backup the big drives. I
can't remember how much data the big 14" drives stored, but I remember
something about 108MB or 128MB each.

The main computer was about chest high, about 4' wide and maybe 10'
long. It ran on 3-phase 208VAC/416VAC, your choice. There were 4 IBM
terminals to feed it and massage its output and a massive half-ton chain
printer that could eat a whole box of z-fold tractor paper in about 4
minutes printing not X characters/second but X LINES per second at a
furious pace. It sounded like a buzz saw trimming the bark off trees in
a sawmill when printing, even inside its "quiet cabinet" included in the
package.

A few of us were rummaging around in my storage building looking for
something and the group stumbled upon my Systems 32. One of the guys
was in the trucking business and had a big warehouse wired for 3-phase
power. He volunteered to power it if we trucked it over there in one of
his vans, just to see if we could run it. There were 4 huge boxes of
cables.

We got it wired up next to one of the large forklift chargers in the
warehouse and, after actually reading the manuals a bit, we dared to
toss caution to the wind and flip the big switch to ON. The floppy
bootloader found what it was looking for and all 4 screens lit up with
the original company's text-based logo. It was still loaded with their
current inventory from the day it was unplugged and replaced. We
ordered vast quantities of industrial supplies and entered over $480,000
to accounts payable in the next few hours. We had a great time. We
stole boxes of paper from the warehouse office and dumped the inventory
and vendor lists to the printer making an awful racket!...(c;]

As the "new" wore off our toy, we shut her down and rolled her back into
the truck. I stripped off some really impressive power supply
components from the main console and saved a couple of single-phase fans
I thought might be useful to my projects. The rest of it we backed the
truck up to a very large dumpster and put a big ramp from the truck
tailgate to the dumpster's lip. I bet that driver had trouble picking
that dumpster up over his cab to dump its half million dollar contents
into the crusher in the back that week.....(c;]

I dumped the manuals later on with the software backup disks while
cleaning out some file cabinets to put church organ manuals into a few
years later. Pity....money poured right down a hole it was....

OT but very useful...
 

"Marc Heusser" d wrote in
message ...
In article lutions,
"Capt. JG" wrote:

I also just downloaded TideApp which is the TideTool equiv. for the
phone.
Nice.

There is also Tides.
Comparing with the official tide tables for Hamburg, Germany (at
www.bsh.de) though, both of them were off by quite a bit - Tides was
better but still too far off.

Marc

--
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http://www.heusser.com


I don't know about either's absolute accuracy, but all in all, I like
TideApp better. Tides doesn't have a graphical view, at least I couldn't
find one. Sometimes, I don't want to look at the numbers, just the trend.

--
"j" ganz @@
www.sailnow.com

OT Computer Memory (was OT but very useful...)
 

"Larry" wrote in message
...
Brian Whatcott wrote in news:rmBxl.21117
:

This was a step back in one way: you could lose power on a core
computer and when it came up again, the code and data were still there
in core. Not so with solid state memory....

But I'll stop here....
Brian W



A local Catholic church gave me a complete IBM Systems 32, including OS
and small business software for a small manufacturing firm. It had two
fixed drives, huge noisy ones; an 8" floppy drive that had a boot loader
on floppy and a large data cassette drive to backup the big drives. I
can't remember how much data the big 14" drives stored, but I remember
something about 108MB or 128MB each.

The main computer was about chest high, about 4' wide and maybe 10'
long. It ran on 3-phase 208VAC/416VAC, your choice. There were 4 IBM
terminals to feed it and massage its output and a massive half-ton chain
printer that could eat a whole box of z-fold tractor paper in about 4
minutes printing not X characters/second but X LINES per second at a
furious pace. It sounded like a buzz saw trimming the bark off trees in
a sawmill when printing, even inside its "quiet cabinet" included in the
package.

A few of us were rummaging around in my storage building looking for
something and the group stumbled upon my Systems 32. One of the guys
was in the trucking business and had a big warehouse wired for 3-phase
power. He volunteered to power it if we trucked it over there in one of
his vans, just to see if we could run it. There were 4 huge boxes of
cables.

We got it wired up next to one of the large forklift chargers in the
warehouse and, after actually reading the manuals a bit, we dared to
toss caution to the wind and flip the big switch to ON. The floppy
bootloader found what it was looking for and all 4 screens lit up with
the original company's text-based logo. It was still loaded with their
current inventory from the day it was unplugged and replaced. We
ordered vast quantities of industrial supplies and entered over $480,000
to accounts payable in the next few hours. We had a great time. We
stole boxes of paper from the warehouse office and dumped the inventory
and vendor lists to the printer making an awful racket!...(c;]

As the "new" wore off our toy, we shut her down and rolled her back into
the truck. I stripped off some really impressive power supply
components from the main console and saved a couple of single-phase fans
I thought might be useful to my projects. The rest of it we backed the
truck up to a very large dumpster and put a big ramp from the truck
tailgate to the dumpster's lip. I bet that driver had trouble picking
that dumpster up over his cab to dump its half million dollar contents
into the crusher in the back that week.....(c;]

I dumped the manuals later on with the software backup disks while
cleaning out some file cabinets to put church organ manuals into a few
years later. Pity....money poured right down a hole it was....



I almost bought a Dec 20 years ago... thought of putting it in my garage and
using it as a timeshare. :)


--
"j" ganz @@
www.sailnow.com

OT but very useful...
 

In article ,
Justin C wrote:

I also just downloaded TideApp which is the TideTool equiv. for the phone.
Nice.

There is also Tides.
Comparing with the official tide tables for Hamburg, Germany (at
www.bsh.de) though, both of them were off by quite a bit - Tides was
better but still too far off.

Out of interest, how far is too far?

Ok, here comes the comparison.
(LW low water, HW high water, 24h time, height above map reference zero
for Hamburg, St. Pauli, Germany, 53°32'44"N 9°58'12"E, GMT+1
for Monday, 23 March 2009
(This is the large port of Hamburg)

The reference: prediction by th BSH
(www.bsh.de, free)
HW 0151 3.9m
LW 0927 0.4m
HW 1439 3.7m
LW 2147 0.5m

WXTide32 (latest version 4.7, 25 Feb 2007, wxtide32.com,
for 53°33.00'N 9°58.02'E, free)
HW 0133 3.1m
LW 0905 0.5m
HW 1428 3.0m
LW 2113 0.6m

Tides (iPhone, version 2.0, free, but ad ridden)
I was not able to enter Hamburg, Germany, a major port, with the new
version, even when I entered the exact coordinates and searched for
nearby prediction spots.

TideApp (iPhone, version 2.5, ads to come - I'd rather pay something for
it)
HW 0143 3.9m
LW 0901 0.75m
HW 1425 3.7
LW 2128 0.75m
Times seem to be within half an hour, heights within half a metre
good enough for planning

Mr Tides X (Mac OS X. version 2.5.6.2,
http://homepage.mac.com/augusth/MrTides/, based on XTide 2.8, free)
HW 0143 3.9m
LW 0901 0.75m
HW 1425 3.7
LW 2128 0.75m

Any comparisons for other ports to assess reliability would be nice,
especially for TideApp.

HTH

Marc

--
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http://www.heusser.com

OT but very useful...
 

On Sun, 22 Mar 2009 21:45:45 +0000, Larry wrote:

(Richard Casady) wrote in news:49c969b9.9397015
:

Eight bits, one byte, per tube.


I'd love to know the physics behind how they did that. Dual triodes, such
as 12AX7, 12AT7, 12AU7, or even earlier 6SN7 were used as latching flip
flops, but they only stored one bit...0 or 1. To get 8 reliable levels
would be magic. They did use a neon counter tube that had multiple
cathodes. Perhaps that is the "tube" that did a byte.

They told us that each tube stored 8 bits as charged spots on the
cathode. Maybe the cathode was in segments. The computer was called
the " Cyclone " and had its own unique language, EERIE. You programmed
it with a pencil. Your page went to some guy who punched the cards.
Some other guy fed the box. The first thing I had it do was an
approximation of the area under a curve by breaking it down into a
hundred rectangles. Computers are fast? You could learn calculus in
less time.

Casady

OT Computer Memory (was OT but very useful...)
 

Brian Whatcott wrote:
Larry wrote:
(Richard Casady) wrote in
news:49c969b9.9397015
@news.east.earthlink.net:

Eight bits, one byte, per tube.


I'd love to know the physics behind how they did that. Dual triodes,
such as 12AX7, 12AT7, 12AU7, or even earlier 6SN7 were used as
latching flip flops, but they only stored one bit...0 or 1. To get 8
reliable levels would be magic. They did use a neon counter tube that
had multiple cathodes. Perhaps that is the "tube" that did a byte.



[long nostalgic bit follows...]

Well, this was a slightly mixed memory, I'd say. the idea of 8 bit
collections called bytes came later, around the IBM 360 time frame.
The early CDC machines I worked on used 6-bit "bytes" and used 36 or 60
bit words for instructions. IIRC they even did BCD math on 4 bit
nibbles.


Previous IBM incarnations like the 1401 used eight bits plus parity:
6 data, and two marker bits for laying out data fields - if you wanted
to add two 1000 decimal place numbers, no problem. Just lay down the
field length markers and issue ADD

But computer memories were kinda weird and wonderful.
There was quite a development effort into CRT memory storage:
allocate an X and Y value for each bit and point the electron beam at it
to set and to read it out. Hundreds or thousands of bits.
Trouble was the beam position drifted, which didn't help data integrity.

I worked on a CRT that use magnetic torsion rod memory. Magnets on one
end would send torsion pulses down the rod which were picked up on the
other end. This was synchronized with a spinning disk that had the
character masks for the screen!



The serial computers used a nickel line for short term storage: you
pulsed an electromagnet at one end to set a pulse going for a '1' or no
pulse for '0' so a stream of pulses would run down the nickel wire at
the speed of sound to the sense coil at the other end, where the data
would turn round to the start coil and start over.
That was called magnetostriction.
Others used mercury delay lines. Or coil delays.

Yes, I remember the mercury delay systems. Fortunately they only gained
favor in the analog world.

One of my favorite "antique" books (next to my old Bowditch and Coast
Pilots) is "High Speed Computing Devices" published in 1950. They
describe in detail a new device called the transistor: "It seems likely
that this device will simply computer circuits considerably."

....
This was a step back in one way: you could lose power on a core
computer and when it came up again, the code and data were still there
in core. Not so with solid state memory....

My lab had one older "mini computer," a DG Nova with limited core memory
(8K?) and a teletype with paper tape reader, that we we used as a
programmable calculator. It was loaded with Basic and was ready to go
on powerup. A machine like that, but with 64 kB and floppies became my
first "personal computer" in 1979.

OT Computer Memory (was OT but very useful...)
 

"jeff" wrote in message
...
My lab had one older "mini computer," a DG Nova with limited core memory
(8K?) and a teletype with paper tape reader, that we we used as a
programmable calculator. It was loaded with Basic and was ready to go on
powerup. A machine like that, but with 64 kB and floppies became my first
"personal computer" in 1979.

That sounds like a Commodore 64.
I started with one of those and still have the complete outfit includung
monitor,floppy drive etc., and loads of operating manuals telling you how to
'poke' and 'peek' to get the result you wanted.
Classic museum piece now, I think. I'll keep it until it becomes really
valuable.
Did some good work on it though. My wife wrote a book, quite a long one and
illustrated with many photos , and on my C64 I set the whole thing up as
'camera ready copy' and saved the whole cost of our computer outfit when we
went to a publisher with it. You had to load the word processing programme
every time you booted up but once loaded it was a pretty decent programme.
There was 'superbase' too-quite a useful database programme which also had
to be loaded each time you needed it.
Was that all really almost 30 years ago??

OT Computer Memory (was OT but very useful...)
 

"Edgar" wrote in message
...

"jeff" wrote in message
...
My lab had one older "mini computer," a DG Nova with limited core memory
(8K?) and a teletype with paper tape reader, that we we used as a
programmable calculator. It was loaded with Basic and was ready to go on
powerup. A machine like that, but with 64 kB and floppies became my
first "personal computer" in 1979.

That sounds like a Commodore 64.
I started with one of those and still have the complete outfit includung
monitor,floppy drive etc., and loads of operating manuals telling you how
to 'poke' and 'peek' to get the result you wanted.
Classic museum piece now, I think. I'll keep it until it becomes really
valuable.
Did some good work on it though. My wife wrote a book, quite a long one
and illustrated with many photos , and on my C64 I set the whole thing up
as 'camera ready copy' and saved the whole cost of our computer outfit
when we went to a publisher with it. You had to load the word processing
programme every time you booted up but once loaded it was a pretty decent
programme. There was 'superbase' too-quite a useful database programme
which also had to be loaded each time you needed it.
Was that all really almost 30 years ago??



I gave my father one of those for his birthday. Unfortunately, being who he
was he tried to take it apart and broke it. That happened for all the
subsequent computers I gave him until I got him one of the Apples that
needed a dedicated tool.

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www.sailnow.com