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>>> Was there ever a time when programs were entered into memory via
>>> switches rather than some other medium?
>>
>> I do that all the time :-)
>
> *sigh*
:-D
> I ment where you have a bank of switches to select a memory address, and a
> second bank of switches to select what datum to write there.
I did that at university. We had a hex keypad to write machine code
instructions to RAM. IIRC we had to write a program to do some thermostat
control of a heater or something - extra marks for proportional control.
But then this was just part of the CPU course to get us familiar with
instructions and stuff.
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Invisible <voi### [at] dev null> wrote:
> Clarence1898 wrote:
>
> > This is an image of the first mainframe I worked with in 1969.
> >
> > http://www-03.ibm.com/ibm/history/exhibits/mainframe/images/2423PH2050.jpg
>
> Trippy! :-D
>
> > It was an IBM 360 model 50. The tape drives in the background are IBM 2400
> > models. The machine was controlled from the IBM 1052 console, a modified IBM
> > typewriter. The IBM 2501 just in front and to the left of the operator could
> > read about 1000 cards per minute. The IBM 2311 disk drives in the foreground
> > had removable disk packs which held a little more than 7 MB IIRC.
>
> Any idea how much all this gear cost?
Depending on the size of the original 360 series machines, purchase price ranged
from around $100000 to several million. The companies I worked for always
leased their machines. I wasn't involved in the financial end, but I think we
paid somewhere around $20000 to $30000 per month for the 360/50.
That was for a machine with 128KB of ram, single processor rated at about 0.2
MIPS, with 16 IBM2314 disk drives with 29MB each, and 8 7-track tape drives, an
IBM 2540 card read/punch, plus a couple of IBM 2701 telecommunications
controllers.
>
> > As you can see
> > there were quite a few flashing lights on the front panel. Besides showing the
> > status info, you could use them to read/alter the contents of memory.
> > Sometime I think they were a lot more fun then.
>
> Presumably not at the times when you wanted to get some actual *work*
> done? ;-)
The machine was busy running production work weekdays and saturday. Since I
installed the os, IBM OS/360, all my testing had to be done on Sunday. So a lot
of desk checking and setup through the week getting ready for the weekend.
Isaac.
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>> I ment where you have a bank of switches to select a memory address,
>> and a second bank of switches to select what datum to write there.
>
> I did that at university. We had a hex keypad to write machine code
> instructions to RAM. IIRC we had to write a program to do some
> thermostat control of a heater or something - extra marks for
> proportional control. But then this was just part of the CPU course to
> get us familiar with instructions and stuff.
Right. So you type stuff in hex rather than raw binary, and it
automatically advances to the next address?
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>> I did that at university. We had a hex keypad to write machine code
>> instructions to RAM. IIRC we had to write a program to do some
>> thermostat control of a heater or something - extra marks for
>> proportional control. But then this was just part of the CPU course to
>> get us familiar with instructions and stuff.
>
> Right. So you type stuff in hex rather than raw binary, and it
> automatically advances to the next address?
Yeh something like that, I don't remember the exact details. I think you
could enter a memory address and hit the "address" button or something and
it would then accept instructions from that point, and then there was a
"run" button. Pretty basic, but armed with the instruction set datasheet
you could actually write stuff that worked. IIRC they had a few channels of
analogue and digital IO mapped to certain addresses that were connected to
useful stuff like LEDs, temperature sensors and heaters.
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>> Right. So you type stuff in hex rather than raw binary, and it
>> automatically advances to the next address?
>
> Yeh something like that, I don't remember the exact details. I think
> you could enter a memory address and hit the "address" button or
> something and it would then accept instructions from that point, and
> then there was a "run" button. Pretty basic, but armed with the
> instruction set datasheet you could actually write stuff that worked.
> IIRC they had a few channels of analogue and digital IO mapped to
> certain addresses that were connected to useful stuff like LEDs,
> temperature sensors and heaters.
Mmm, tasty.
The closest I ever came to doing something like this was assembling a
program for my dad's C64 by hand. (I still have the book with the
op-code table in it. And, 20 years later, I still remember that RTS is
96 decimal. How sad is that?)
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On 18/05/2010 12:36 PM, Invisible wrote:
> Stephen wrote:
>
>> When I started working in computing in 1969, the Honeywell H416 then
>> later H316
>
> Oh yes - apparently Honeywell used to make computers...
Yes the ones I worked on were for process control and they had core
memory. Ferrite rings threaded with address wires and read write wires,
by hand. The H316 could have 4 K of memory.
> Does the tape have a single row of holes? Or does it have multiple
> parallel rows? How easy is it to tear the stuff?
>
Parallel rows, one traction hole at twice the pitch of the data holes
and seven or eight data holes depending on the parity.
>> After the loader tape was read you then read the program using the
>> paper tape reader. Only then could you enter any data.
>
> From tape or card, presumably?
Yes or from sense switches from the process it controlled.
>
>> In 1976 Burroughs Machines were manufacturing 96 column card readers.
>
> I gather Burroughs got bought to form Unisys?
>
After my time.
>> The first computer I ever saw was in 1997 at Glasgow University. It
>> was an analogue machine that used valves.
>
> 1997? o_O
Oops! 1967 :-)
--
Best Regards,
Stephen
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http://www.columbia.edu/acis/history/fisk.pdf
Hmm, interesting. Some of the guys I went to uni with learned COBOL. All
they could tell me about it is "if you miss out a dot, you get an error
message 300 lines later". Sounds delightful...
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Invisible <voi### [at] devnull> wrote:
> I had always assumed that the first computers were like current
> computers, just using relays or whatever instead of transisters, and
> with vastly inferior specifications.
>
> However, it appears that this isn't the case.
>
> For example, I thought they all used latch circuits for memory, but
> apparently not. There were things like core memory, which I'd never
> heard of. Presumably it's faster and cheaper to make core memory as
> opposed to wiring up thousands of latch circuits?
>
"Core" memory was invented in the late 40s, but didn't come into wide use until
the early 50s. I think the IBM 360s used core memory. The IBM 370s and all
later machines used integrated circuits for memory. We added 1MB of memory to
an IBM 370/168 in the mid 70s. Price? $50000. There were several advantages to
core memory. First its not volatile, you don't loose the contents of memory
when you power off the system. Second its relatively immune to electromagnetic
radiation, so it does not require shielding when used in hostile environements.
Many military aircraft used core memory in their avionics. I think the space
shuttles originally used core memory in their computers.
> Another example. According to legend, there was a time when if you
> wanted to run a program, you used a machine not unlike a typewriter to
> punch holes into a card. You "type in" the program onto punch cards like
> this, and only once the entire program and all its data has been punched
> do you even go near the actual *computer*. You feed the cards into a
> reader. It reads them all, and then spends the next six months running
> the program. Finally, you get a stack of new punched cards representing
> the results.
>
> Does anybody know approximately when this time was?
When I was at university in the mid to late 60s, I took a FORTRAN programming
course. Punch program into cards, place in card tray, come back 4 to 6 hours
later and pick up your card deck and output listing. Fix your typos and bugs
and repeat the above process until the program works. At my first commercial
job, it was similar. Punch you program into cards, place in the card reader,
and wait for the output to appear on the printer. Where I worked cards were used
until the mid 1980s. We had cabinet after cabinet filled with punched card
programs. The fun began after you punched in your 1000 card program and dropped
the deck on the way to the card reader. After you did that a couple of times,
you started adding sequence numbers to the deck.
>
> For that matter, does anybody have a broad timeline of when various
> technologies were in use? What are the dates for things like core
> memory, drum memory, punch cards, magnetic tape, relays, vacuum tubes,
> transistors, ICs, etc?
>
> Was there ever a time when programs were entered into memory via
> switches rather than some other medium?
>
> Was there ever a "punched tape" medium similar to punch cards?
>
Yes. Several different varieties of tape. Different widths, different hole
styles etc. I once had to write a driver for the IBM 1056 paper tape reader on
an IBM 370/158 because IBM did not support that device on that machine. That
was kind of fun to do. That was in the early 70s?
> Similarly, you hear people talk about the VAX, the PDP, the varouis IBM
> mainframes and Cray supercomputers. Does anybody know the timeline for
> these, the technologies used and the basic design and performance details?
>
> (Sure, you can look up individual questions on Wikipedia, but the
> articles tend to contain huge amounts of minute detail about specific
> things. I'm trying to get a general overview of an entire era.)
I think you will have to look it up. There is just too much information to
enter here. I have work exclusively on IBM machines my entire career. So I
can't say anything about other manufacturers. Very briefly IBM 360 series,
transistor circuits, core memory, mid 60s to early 70s. Early IBM 370 series in
the early 70s, integrated circuits, to later 370 series with higher density
circuits in the mid 80s. The 3090 series machines with very high density
circuits until the mid 90s. The s/390 series user cmos technology and were air
cooled. The older machines used bipolar technology and many were water cooled.
Finally the z/series, again cmos technology. Speeds ranged from .2 MIPS for a
360/50, 1 MIP for a 370/158, 15 MIPS for a 3083. The current machines I work
with today, 2 z/9 BC processors are rated at 600 and 335 MIPS.
The top of the line z/10 is almost 30000 MIPS.
Isaac
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> "Core" memory was invented in the late 40s, but didn't come into wide use until
> the early 50s. I think the IBM 360s used core memory.
How about drum memory? Or the various delay lines?
> The IBM 370s and all later machines used integrated circuits for memory.
As in, whole memory chunks on a single IC? Or just two latches per IC?
Or...?
> We added 1MB of memory to an IBM 370/168 in the mid 70s. Price? $50000.
Ouch! o_O
It still somewhat blows my mind that you could do anything useful with
so little memory. Presumably for processing large datasets, most of the
data at any one time would be in secondary storage?
> There were several advantages to core memory.
Yes, so I see.
> When I was at university in the mid to late 60s, I took a FORTRAN programming
> course. Punch program into cards, place in card tray, come back 4 to 6 hours
> later and pick up your card deck and output listing. Fix your typos and bugs
> and repeat the above process until the program works.
Heh, sounds line fun. According to the account I just read, you actually
put one statement per punch card. Is that right? I always assumed that
each card just held X characters of data, and you type until the card is
full, then move to the next one. I didn't realise there was an actual
"significance" to card bounderies. Or is that just for the benefit of
the humans?
> Where I worked cards were used until the mid 1980s.
Wow. I had no idea it persisted that long. In the mid 1980s, I had a C64
to play with, which stored data on audio tape - for more data than any
stack of punch cards. And I don't think the C64 was even particularly
expensive... (I know of a few people who actually used the C64 for work
purposes, would you believe.)
> The fun began after you punched in your 1000 card program and dropped
> the deck on the way to the card reader. After you did that a couple of times,
> you started adding sequence numbers to the deck.
Hell yeah! ;-)
>> Was there ever a "punched tape" medium similar to punch cards?
>
> Yes. Several different varieties of tape.
OK. I guess each manufacturer probably had their own style.
> I once had to write a driver for the IBM 1056 paper tape reader on
> an IBM 370/158 because IBM did not support that device on that machine. That
> was kind of fun to do. That was in the early 70s?
Hmm, OK.
What sort of access speeds do you get for reading or writing punched
card or tape?
>> Similarly, you hear people talk about the VAX, the PDP, the varouis IBM
>> mainframes and Cray supercomputers. Does anybody know the timeline for
>> these, the technologies used and the basic design and performance details?
>
> I think you will have to look it up. There is just too much information to
> enter here. I have work exclusively on IBM machines my entire career. So I
> can't say anything about other manufacturers.
Fair enough.
> Very briefly IBM 360 series, transistor circuits, core memory,
> mid 60s to early 70s.
As in, discrete transistors on PCBs?
Any ideas on typical memory capacity / clock speed? Data path widths?
> Early IBM 370 series in
> the early 70s, integrated circuits, to later 370 series with higher density
> circuits in the mid 80s.
Are we talking ICs with single logic gates, small logic blocks, or an
entire CPU on a chip?
> The 3090 series machines with very high density
> circuits until the mid 90s.
I had no idea people were still making mainframes in the 90s.
> The s/390 series user cmos technology and were air
> cooled. The older machines used bipolar technology and many were water cooled.
> Finally the z/series, again cmos technology.
Nice consistent naming scheme. Heh. :-/
> Speeds ranged from .2 MIPS for a
> 360/50, 1 MIP for a 370/158, 15 MIPS for a 3083. The current machines I work
> with today, 2 z/9 BC processors are rated at 600 and 335 MIPS.
> The top of the line z/10 is almost 30000 MIPS.
Now if I could figure out what a typical MIPS rating for a normal PC
today is, I'd have something dissimilar to compare it to. :-}
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On 18/05/2010 3:14 PM, Invisible wrote:
> What sort of access speeds do you get for reading or writing punched
> card or tape?
Some of the fast paper tape readers would stream the tape about 15 feet
through the air before it was collected in a large bin. The fun part was
rewinding into a roll.
BTW I forgot. Plain paper tape was easily torn but the tapes used in the
fast readers had a layer of Mylar so they could not be torn, the paper
backing could separate though.
--
Best Regards,
Stephen
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