Groups > alt.folklore.computers > #218654 > unrolled thread

What is the oldest computer that could be used today for real work?

Started by	Jason Evans <jsevans@mailfence.com>
First post	2021-09-05 09:55 +0000
Last post	2021-10-08 07:27 -0700
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#219044

From	Charlie Gibbs <cgibbs@kltpzyxm.invalid>
Date	2021-09-26 04:24 +0000
Message-ID	<uCS3J.125898$F26.47446@fx44.iad>
In reply to	#219028

On 2021-09-25, Andreas Kohlbach <ank@spamfence.net> wrote:

> On Sat, 25 Sep 2021 07:19:54 -0400, J. Clarke wrote:
>>
>> On 25 Sep 2021 04:22:50 -0300, Mike Spencer
>> <mds@bogus.nodomain.nowhere> wrote:
>>
>>> Yes, I do know that.  But the US Navy operates *war*ships.  If the
>>> Navy is ever again confronted with an actual war -- something beyond
>>> sending helicopter gunships or drones after "insurgents" or showing
>>> the flag in the South China Sea -- against a capable opponent,
>>> GPS/satnav is going to be the opponent's early target.  Naval mariners
>>> have long had the attitude that they should be prepared to cope when X
>>> fails for almost all values of X.
>>
>> Satnav isn't that easy to kill you know.  It's not like you can shoot
>> one down with a MiG 21.  Besides, there are 4 different systems.  To
>> render satnav unusable would require destroying upwards of 100
>> different satellites.
>
> From what I read there are 31 (US) GPS satellites in orbit. Cannot find
> out the distance to one to another. Might be less than 1000
> kilometers. If one nuke is fired at a distance of 500 kilometers between
> two satellites it might take out both of them. So you (China, or who ever
> is the enemy in a future war) need 15 nukes to take out the whole
> system. Shouldn't be a problem. Should be even enough to take down only a
> few of them to make the system useless.

Not really.  If you can pick up three satellites you have a 2D position.
Four satellites will give you a 3D position.  Five will give you RAIM
(redundant autonomous integrity monitoring).  As long as you have that
much of a subset in view, you can still navigate, although perhaps at
reduced precision.

Occasionally NOTAMs (notices to airmen) are issued warning about possible
interruptions to GPS service.  They specify a time range when GPS signals
may become unreliable within a certain radius of a given spot (smaller
radii at low altitudes, larger ones at higher altitudes).  The specified
location is always at a military base; they're experimenting with jamming
the signals.

-- 
/~\  Charlie Gibbs                  |  Life is perverse.
\ /  <cgibbs@kltpzyxm.invalid>      |  It can be beautiful -
 X   I'm really at ac.dekanfrus     |  but it won't.
/ \  if you read it the right way.  |    -- Lily Tomlin

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#219047

From	Branimir Maksimovic <branimir.maksimovic@gmail.com>
Date	2021-09-26 07:10 +0000
Message-ID	<V1V3J.15305$d82.7531@fx21.iad>
In reply to	#219044

On 2021-09-26, Charlie Gibbs <cgibbs@kltpzyxm.invalid> wrote:
>
> Not really.  If you can pick up three satellites you have a 2D position.
> Four satellites will give you a 3D position.  Five will give you RAIM
> (redundant autonomous integrity monitoring).  As long as you have that
> much of a subset in view, you can still navigate, although perhaps at
> reduced precision.
>
> Occasionally NOTAMs (notices to airmen) are issued warning about possible
> interruptions to GPS service.  They specify a time range when GPS signals
> may become unreliable within a certain radius of a given spot (smaller
> radii at low altitudes, larger ones at higher altitudes).  The specified
> location is always at a military base; they're experimenting with jamming
> the signals.
>
Not really jonosfere, you need only one.
Also, who first build Tesla Weapon planes will became thing of the past.
Also to improve radar for detecting objects that does not reflect signals
from 20km range...

-- 

7-77-777
Evil Sinner!

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#219054

From	J. Clarke <jclarke.873638@gmail.com>
Date	2021-09-26 12:10 -0400
Message-ID	<d701lg1tvgbdvqckbntckbs5mdpuefvphl@4ax.com>
In reply to	#219044

On Sun, 26 Sep 2021 04:24:58 GMT, Charlie Gibbs
<cgibbs@kltpzyxm.invalid> wrote:

>On 2021-09-25, Andreas Kohlbach <ank@spamfence.net> wrote:
>
>> On Sat, 25 Sep 2021 07:19:54 -0400, J. Clarke wrote:
>>>
>>> On 25 Sep 2021 04:22:50 -0300, Mike Spencer
>>> <mds@bogus.nodomain.nowhere> wrote:
>>>
>>>> Yes, I do know that.  But the US Navy operates *war*ships.  If the
>>>> Navy is ever again confronted with an actual war -- something beyond
>>>> sending helicopter gunships or drones after "insurgents" or showing
>>>> the flag in the South China Sea -- against a capable opponent,
>>>> GPS/satnav is going to be the opponent's early target.  Naval mariners
>>>> have long had the attitude that they should be prepared to cope when X
>>>> fails for almost all values of X.
>>>
>>> Satnav isn't that easy to kill you know.  It's not like you can shoot
>>> one down with a MiG 21.  Besides, there are 4 different systems.  To
>>> render satnav unusable would require destroying upwards of 100
>>> different satellites.
>>
>> From what I read there are 31 (US) GPS satellites in orbit. Cannot find
>> out the distance to one to another. Might be less than 1000
>> kilometers. If one nuke is fired at a distance of 500 kilometers between
>> two satellites it might take out both of them. So you (China, or who ever
>> is the enemy in a future war) need 15 nukes to take out the whole
>> system. Shouldn't be a problem. Should be even enough to take down only a
>> few of them to make the system useless.
>
>Not really.  If you can pick up three satellites you have a 2D position.
>Four satellites will give you a 3D position.  Five will give you RAIM
>(redundant autonomous integrity monitoring).  As long as you have that
>much of a subset in view, you can still navigate, although perhaps at
>reduced precision.
>
>Occasionally NOTAMs (notices to airmen) are issued warning about possible
>interruptions to GPS service.  They specify a time range when GPS signals
>may become unreliable within a certain radius of a given spot (smaller
>radii at low altitudes, larger ones at higher altitudes).  The specified
>location is always at a military base; they're experimenting with jamming
>the signals.

In addition to what Charlie says:

There are four constellations.  We have one, Russia has one, the EU
has one, and China has one.  India is working on one.  In a war in
which the US is involved, we can count on access to at least two of
those.

Andreas could not find out the distance between the satellites because
there is no fixed distance.  They are in 6 orbital planes with 4 or
more satellites per plane, at an orbital radius of roughly 16503
miles.  The gory details can be found in
https://www.gps.gov/technical/ps/2020-SPS-performance-standard.pdf.
You may find
https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/cami/library/online_libraries/aerospace_medicine/tutorial/media/iii.4.1.4_describing_orbits.pdf
helpful in understanding the nomenclature used.

Calculating the actual closest approach is more effort than I want to
go into for a casual conversation.  For a rough estimate of the
distance between them consider a sphere of radius 16503 miles.  That
has an area of 3,422,438,583 square miles.  Divide that by 24 and you
get 142601607 square miles per satellite.  Figure the radius of a
circle of that area and you get 6737.  Double that and you have 13474
miles.  Very very rough estimate, and will vary.

Next, there's the notion of using a nuclear weapon to kill two
satellites.  Let's look at that.  Assume the weapon yield is 60
megatons.  The largest nuclear weapon ever demonstrated (Tsar Bomba,
Soviet test AN602) had a yield of 50-58 megatons depending on whose
data you believe so that is a reasonable limit. There are no currently
operational launch systems which could carry a weapon that size to the
altitude required to attack GPS. 

Blast effects.  In air the overpressure at 40 miles would be down to 1
psi.  At that overpressure breaking windows is the major effect.
That's in air--space is a vacuum so the blast effects occur over a
much smaller radius.

Thermal effects:  Beyond 50 miles the thermal intensity is enough to
produce a sunburn in humans.

Radiation:  A Tsar Bomba sized weapon could produce enough radiation
to damage unshielded rad-hard ICs at up to about 7500 miles.  The
amount of shielding installed on GPS satellites does not appear to be
available in unclassified documents.  At the 

EMP:
This is the one that people always trot out.  EMP is an atmospheric
effect--it is the result of interaction of the nuclear weapon with
both the magnetic field and the atmosphere and depends on gamma rays
stripping electrons from atoms in the atmosphere.  Its nature is that
it is directed downward, not upward and there's not enough atmosphere
at the altitude of GPS satellites to generate an effective E1 or E2
pulse at their altitude.  An E3 pulse could still occur but it
requires very long transmission lines to have an effect, and that is
something that satellites do not have.

Intensification of the Van Allen Belt:
This is something that was demonstrated in several US and Soviet
nuclear tests.  It is not an issue for GPS as they are above the lower
belt and below the upper one.

Bottom line:
Trying to take out two satellites with one nuclear weapon is unlikely
to take out either and would require a Starship/Long March 9/Saturn
V/N1 class launch vehicle, none of which exist in operational form at
this time.  And if there is to be more than 1 such attempt there will
have to be hardened silos for such vehicles, which again do not exist
anywhere at this time--after the first attempt the launch facility
would become a priority target.

Note also that ICBMs are not designed to attack satellites.  They
could be repurposed to do so but it would require essentially
reworking them into orbital launchers and their payload would be
significantly reduced.

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#219089

From	usenet@only.tnx (Questor)
Date	2021-09-28 13:13 +0000
Message-ID	<615314b6.14699917@news.dslextreme.com>
In reply to	#219054

On Sun, 26 Sep 2021 12:10:34 -0400, J. Clarke <jclarke.873638@gmail.com> wrote:
>On Sun, 26 Sep 2021 04:24:58 GMT, Charlie Gibbs
><cgibbs@kltpzyxm.invalid> wrote:
>>On 2021-09-25, Andreas Kohlbach <ank@spamfence.net> wrote:
>>>On Sat, 25 Sep 2021 07:19:54 -0400, J. Clarke wrote:
>>>>On 25 Sep 2021 04:22:50 -0300, Mike Spencer
>>>><mds@bogus.nodomain.nowhere> wrote:
>>>>>Yes, I do know that.  But the US Navy operates *war*ships.  If the
>>>>>Navy is ever again confronted with an actual war -- something beyond
>>>>>sending helicopter gunships or drones after "insurgents" or showing
>>>>>the flag in the South China Sea -- against a capable opponent,
>>>>>GPS/satnav is going to be the opponent's early target.  Naval mariners
>>>>>have long had the attitude that they should be prepared to cope when X
>>>>>fails for almost all values of X.
>>>>
>>>>Satnav isn't that easy to kill you know.  It's not like you can shoot
>>>>one down with a MiG 21.  Besides, there are 4 different systems.  To
>>>>render satnav unusable would require destroying upwards of 100
>>>>different satellites.
>>>
>>>From what I read there are 31 (US) GPS satellites in orbit. Cannot find
>>>out the distance to one to another. Might be less than 1000
>>>kilometers. If one nuke is fired at a distance of 500 kilometers between
>>>two satellites it might take out both of them. So you (China, or who ever
>>>is the enemy in a future war) need 15 nukes to take out the whole
>>>system. Shouldn't be a problem. Should be even enough to take down only a
>>>few of them to make the system useless.
>>
>>Not really.  If you can pick up three satellites you have a 2D position.
>>Four satellites will give you a 3D position.  Five will give you RAIM
>>(redundant autonomous integrity monitoring).  As long as you have that
>>much of a subset in view, you can still navigate, although perhaps at
>>reduced precision.
>>
>>Occasionally NOTAMs (notices to airmen) are issued warning about possible
>>interruptions to GPS service.  They specify a time range when GPS signals
>>may become unreliable within a certain radius of a given spot (smaller
>>radii at low altitudes, larger ones at higher altitudes).  The specified
>>location is always at a military base; they're experimenting with jamming
>>the signals.
>
>In addition to what Charlie says:
>
>There are four constellations.  We have one, Russia has one, the EU
>has one, and China has one.  India is working on one.  In a war in
>which the US is involved, we can count on access to at least two of
>those.
>
>Andreas could not find out the distance between the satellites because
>there is no fixed distance.  They are in 6 orbital planes with 4 or
>more satellites per plane, at an orbital radius of roughly 16503
>miles.  The gory details can be found in
>https://www.gps.gov/technical/ps/2020-SPS-performance-standard.pdf.
>You may find
>https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/cami/library/online_libraries/aerospace_medicine/tutorial/media/iii.4.1.4_describing_orbits.pdf
>helpful in understanding the nomenclature used.
>
>Calculating the actual closest approach is more effort than I want to
>go into for a casual conversation.  For a rough estimate of the
>distance between them consider a sphere of radius 16503 miles.  That
>has an area of 3,422,438,583 square miles.  Divide that by 24 and you
>get 142601607 square miles per satellite.  Figure the radius of a
>circle of that area and you get 6737.  Double that and you have 13474
>miles.  Very very rough estimate, and will vary.

The problem with your calculation is that assumes the satellites are equally
likely to be anywhere around the planet, when in fact by your statement they are
in one of six orbital planes.  I don't know what the width of those planes is,
but go ahead and calculate their total area, taking into account where they
overlap.  I'll let you simplify the problem by assuming flat bands, instead of
matching the Earth's curvature.  I'm sure the total area is much smaller.
Targeting the area where one or more planes intersect may increase
effectiveness.

I don't have any major problem with the rest of your analysis, which leads me to
suggest that a far more practical method to take out the GPS network would be to
launch a payload of small ball bearings into the same orbital plane but going in
the other direction from the satellites.  The collateral damage from setting off
a Kessler Syndrome may be very high, but hey, war is hell, right?


>Next, there's the notion of using a nuclear weapon to kill two
>satellites.  Let's look at that.  Assume the weapon yield is 60
>megatons.  The largest nuclear weapon ever demonstrated (Tsar Bomba,
>Soviet test AN602) had a yield of 50-58 megatons depending on whose
>data you believe so that is a reasonable limit. There are no currently
>operational launch systems which could carry a weapon that size to the
>altitude required to attack GPS. 
>
>Blast effects.  In air the overpressure at 40 miles would be down to 1
>psi.  At that overpressure breaking windows is the major effect.
>That's in air--space is a vacuum so the blast effects occur over a
>much smaller radius.
>
>Thermal effects:  Beyond 50 miles the thermal intensity is enough to
>produce a sunburn in humans.
>
>Radiation:  A Tsar Bomba sized weapon could produce enough radiation
>to damage unshielded rad-hard ICs at up to about 7500 miles.  The
>amount of shielding installed on GPS satellites does not appear to be
>available in unclassified documents.  At the 
>
>EMP:
>This is the one that people always trot out.  EMP is an atmospheric
>effect--it is the result of interaction of the nuclear weapon with
>both the magnetic field and the atmosphere and depends on gamma rays
>stripping electrons from atoms in the atmosphere.  Its nature is that
>it is directed downward, not upward and there's not enough atmosphere
>at the altitude of GPS satellites to generate an effective E1 or E2
>pulse at their altitude.  An E3 pulse could still occur but it
>requires very long transmission lines to have an effect, and that is
>something that satellites do not have.
>
>Intensification of the Van Allen Belt:
>This is something that was demonstrated in several US and Soviet
>nuclear tests.  It is not an issue for GPS as they are above the lower
>belt and below the upper one.
>
>Bottom line:
>Trying to take out two satellites with one nuclear weapon is unlikely
>to take out either and would require a Starship/Long March 9/Saturn
>V/N1 class launch vehicle, none of which exist in operational form at
>this time.  And if there is to be more than 1 such attempt there will
>have to be hardened silos for such vehicles, which again do not exist
>anywhere at this time--after the first attempt the launch facility
>would become a priority target.
>
>Note also that ICBMs are not designed to attack satellites.  They
>could be repurposed to do so but it would require essentially
>reworking them into orbital launchers and their payload would be
>significantly reduced.

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#219086

From	usenet@only.tnx (Questor)
Date	2021-09-28 13:10 +0000
Message-ID	<61531446.14588537@news.dslextreme.com>
In reply to	#219010

On 25 Sep 2021 04:22:50 -0300, Mike Spencer <mds@bogus.nodomain.nowhere> wrote:
>J. Clarke <jclarke.873638@gmail.com> writes:
>>On 24 Sep 2021 03:10:29 -0300, Mike Spencer
>><mds@bogus.nodomain.nowhere> wrote:
>>>AIUI, the US Navy now navigates with Windoes, has for many years.  And
>>>in addition has dropped astral navigation skills as a requirement for
>>>officers.  Furrfu.
>>
>>You do know that a handheld GPS can provide the same information as
>>celestial nav, with vastly greater precision, do you not?  And likely
>>has accurate charts these days.
>
>Yes, I do know that.  But the US Navy operates *war*ships.  If the
>Navy is ever again confronted with an actual war -- something beyond
>sending helicopter gunships or drones after "insurgents" or showing
>the flag in the South China Sea -- against a capable opponent,
>GPS/satnav is going to be the opponent's early target.  Naval mariners
>have long had the attitude that they should be prepared to cope when X
>fails for almost all values of X.
>
>I once toured a Canadian naval ship and asked about a hand-crank
>bolted to a bulkhead in a hold near the bilges.  The answer:  If you
>have a cold ship -- boilers cold, no shore power, nothing operating --
>you unbolt the crank, use it to hand-start an antique single-banger
>diesel.  That generates enough power to start the big 8-cyl diesel
>which in turn compresses enough air to start the two really  big
>16-cyl diesels which then generate enough power to fire up and run
>everything else.

Circling back to something on topic:  this reminds me of bootstraping
a DEC KI-10.  From memory, subject to errors:  first you set a code
in a switch register that selects which device to use, for example, paper tape,
then push another button.  That loads into memory and executes a small
loader program that reads a bigger bootstrap loader from disk, which in
turn loads and starts the operating system (i.e., the monitor in TOPS-10
parlance).

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#219131 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	John Levine <johnl@taugh.com>
Date	2021-09-29 22:10 +0000
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<sj2o7u$2f2l$1@gal.iecc.com>
In reply to	#219086

According to Questor <usenet@only.tnx>:
>Circling back to something on topic:  this reminds me of bootstraping
>a DEC KI-10.  From memory, subject to errors:  first you set a code
>in a switch register that selects which device to use, for example, paper tape,
>then push another button.  That loads into memory and executes a small
>loader program that reads a bigger bootstrap loader from disk, which in
>turn loads and starts the operating system (i.e., the monitor in TOPS-10
>parlance).

Sounds like S/360.  You set the device number of the IPL (initial program load)
device in the switches and pressed the IPL button.  That ran a fixed one instruction
channel program pretending to be at location 0, that read 24 bytes into 0-23, then
executed whatever was read into locaion 8, typically another read command to read
a disk or tape block with real bootstrap, then started the computer by restoring the status word at
location 0 which runs the bootstrap just read in to start up the computer.






-- 
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

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#219136 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	Anne & Lynn Wheeler <lynn@garlic.com>
Date	2021-09-29 17:16 -1000
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<87fstm21nk.fsf@localhost>
In reply to	#219131

John Levine <johnl@taugh.com> writes:
> Sounds like S/360.  You set the device number of the IPL (initial
> program load) device in the switches and pressed the IPL button.  That
> ran a fixed one instruction channel program pretending to be at
> location 0, that read 24 bytes into 0-23, then executed whatever was
> read into locaion 8, typically another read command to read a disk or
> tape block with real bootstrap, then started the computer by restoring
> the status word at location 0 which runs the bootstrap just read in to
> start up the computer.

old post to ibm-main & alt.folklore.computers
http://www.garlic.com/~lynn/2007f.html#1
discussing 360 "3card loader" and BPS (card) loader ... also
references "How to cread CDROM IPL Images" for use with hercules
(mainframe emulator)
https://www.cbttape.org/~jjaeger/cdrom.html

following is from old assemble program ... it can bootstrap load the
assembler program it is included in ... the "xxx"s originally were
EBCDIC HEX

*********************************************************************** 00046000
*                                                                     * 00047000
*        TWO-CARD ABSOLUTE LOADER -- THE FOLLOWING ARE SELF-LOADING   * 00048000
*        IPL-ABLE CARDS THAT LOAD A CHANNEL PROGRAM WHICH FUNCTIONS   * 00049000
*        AS AN ABSOLUTE TXT CARD LOADER, EXECUTING AS A COMMAND CHAIN * 00050000
*        FROM THE INITIAL IPL READ.  IF PUNCHED BEFORE ANY ASSEMBLED  * 00051000
*        INSTRUCTIONS OR DATA, THE TEXT FILE THE ASSEMBLER PRODUCES   * 00052000
*        MAY BE CONVERTED INTO A SELF-LOADING DECK BY USING AN EDITOR * 00053000
*        TO DELETE ANY RECORDS PRECEDING THE TWO LOADER CARDS, WHICH  * 00054000
*        IMMEDIATELY PRECEDE THE FIRST TXT RECORD IN THE TEXT OUTPUT. * 00055000
*                                                                     * 00056000
*        NO CONSTANTS MAY BE ASSEMBLED IN THE ABSOLUTE ADDRESS RANGE  * 00057000
*        X'10' TO X'43', AS THEIR LOADING WOULD OVERWRITE THE LOADER  * 00058000
*        AND CAUSE IPL FAILURES.  THE LOADER OPERATION IS TERMINATED  * 00059000
*        BY LOADING AN ORDINARY NOP CCW AT LOCATION X'40'.  WHEN THE  * 00060000
*        ASSEMBLY BEGINS WITH A 'LABEL START 0' STATEMENT, THIS COULD * 00061000
*        BE ACCOMPLISHED BY INSERTING THE SEQUENCE:                   * 00062000
*                                                                     * 00063000
*                  ORG   LABEL+X'40'                                  * 00064000
*                  CCW   X'03',0,X'20',1                              * 00065000
*                                                                     * 00066000
*        FOLLOWING THE FINAL STATEMENT SPECIFYING ASSEMBLED OUTPUT TO * 00067000
*        BE LOADED.                                                   * 00068000
*                                                                     * 00069000
*                                                                     * 00071000
         PUNCH 'xxxxxxxxxxxxxxxxxxxxxxxxFIRST LOADABLE RECORD' CARD 1 * 00072000
         PUNCH 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' CARD 2 * 00073000
*                                                                     * 00074000
*********************************************************************** 00075000

recent post (to facebook) about early CP67, including discussion of
(assemble output) BPS "TXT" deck loading
http://www.garlic.com/~lynn/2021i.html#61


-- 
virtualization experience starting Jan1968, online at home since Mar1970

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#219149 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	scott@slp53.sl.home (Scott Lurndal)
Date	2021-09-30 14:29 +0000
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<zRj5J.59459$6U3.46789@fx43.iad>
In reply to	#219131

John Levine <johnl@taugh.com> writes:
>According to Questor <usenet@only.tnx>:
>>Circling back to something on topic:  this reminds me of bootstraping
>>a DEC KI-10.  From memory, subject to errors:  first you set a code
>>in a switch register that selects which device to use, for example, paper tape,
>>then push another button.  That loads into memory and executes a small
>>loader program that reads a bigger bootstrap loader from disk, which in
>>turn loads and starts the operating system (i.e., the monitor in TOPS-10
>>parlance).
>
>Sounds like S/360.  You set the device number of the IPL (initial program load)
>device in the switches and pressed the IPL button.  That ran a fixed one instruction
>channel program pretending to be at location 0, that read 24 bytes into 0-23, then
>executed whatever was read into locaion 8, typically another read command to read
>a disk or tape block with real bootstrap, then started the computer by restoring the status word at
>location 0 which runs the bootstrap just read in to start up the computer.

The Burroughs B3500 coldstart process was similar.   The operator would
enter an Initiate I/O (IIO) instruction at address zero and execute it[*];
it would read in the first card and transfer control to data read from
the card, which would read in subsequent cards to complete the bootstrap
program, which would then read in the MCP from tape (or disk (100byte sectors)
or pack (180 byte sectors)) to memory and transfer control to the MCP.

The MCP would complete the coldstart process by initializing the disk
data structures (directory, free list, disk bootstrap sector, etc),
reading in the configuration file (from cards) and completing the coldstart process.

[*] The FE would strap the disk bootstrap channel in the processor so the
halt/load (bootstrap) button would read the first sector of a disk on that
channel and transfer control to it when booting subsequent to the coldstart.

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#219173 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	Peter Flass <peter_flass@yahoo.com>
Date	2021-09-30 17:43 -0700
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<1801483721.654741195.754117.peter_flass-yahoo.com@news.eternal-september.org>
In reply to	#219149

Scott Lurndal <scott@slp53.sl.home> wrote:
> John Levine <johnl@taugh.com> writes:
>> According to Questor <usenet@only.tnx>:
>>> Circling back to something on topic:  this reminds me of bootstraping
>>> a DEC KI-10.  From memory, subject to errors:  first you set a code
>>> in a switch register that selects which device to use, for example, paper tape,
>>> then push another button.  That loads into memory and executes a small
>>> loader program that reads a bigger bootstrap loader from disk, which in
>>> turn loads and starts the operating system (i.e., the monitor in TOPS-10
>>> parlance).
>> 
>> Sounds like S/360.  You set the device number of the IPL (initial program load)
>> device in the switches and pressed the IPL button.  That ran a fixed one instruction
>> channel program pretending to be at location 0, that read 24 bytes into 0-23, then
>> executed whatever was read into locaion 8, typically another read command to read
>> a disk or tape block with real bootstrap, then started the computer by
>> restoring the status word at
>> location 0 which runs the bootstrap just read in to start up the computer.
> 
> The Burroughs B3500 coldstart process was similar.   The operator would
> enter an Initiate I/O (IIO) instruction at address zero and execute it[*];
> it would read in the first card and transfer control to data read from
> the card, which would read in subsequent cards to complete the bootstrap
> program, which would then read in the MCP from tape (or disk (100byte sectors)
> or pack (180 byte sectors)) to memory and transfer control to the MCP.
> 
> The MCP would complete the coldstart process by initializing the disk
> data structures (directory, free list, disk bootstrap sector, etc),
> reading in the configuration file (from cards) and completing the coldstart process.
> 
> [*] The FE would strap the disk bootstrap channel in the processor so the
> halt/load (bootstrap) button would read the first sector of a disk on that
> channel and transfer control to it when booting subsequent to the coldstart.
> 
we 
On the CDC6400, the operator had to toggle in a small “dead start” program
on the console to boot the system.

-- 
Pete

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#219208 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	drb@ihatespam.msu.edu (Dennis Boone)
Date	2021-10-01 22:04 -0500
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<rr-dnW0isNHaUcr8nZ2dnUU7-cmdnZ2d@giganews.com>
In reply to	#219173

 > On the CDC6400, the operator had to toggle in a small “dead start” program
 > on the console to boot the system.

Actually, a switch panel stashed in one of the cabinets held 17B PP
words worth of deadstart program.  It was rarely fiddled with.

De

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#219151 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	Charles Richmond <codescott@aquaporin4.com>
Date	2021-09-30 09:41 -0500
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<sj4ib1$7qb$1@dont-email.me>
In reply to	#219131

On 9/29/2021 5:10 PM, John Levine wrote:
> According to Questor <usenet@only.tnx>:
>> Circling back to something on topic:  this reminds me of bootstraping
>> a DEC KI-10.  From memory, subject to errors:  first you set a code
>> in a switch register that selects which device to use, for example, paper tape,
>> then push another button.  That loads into memory and executes a small
>> loader program that reads a bigger bootstrap loader from disk, which in
>> turn loads and starts the operating system (i.e., the monitor in TOPS-10
>> parlance).
> 
> Sounds like S/360.  You set the device number of the IPL (initial program load)
> device in the switches and pressed the IPL button.  That ran a fixed one instruction
> channel program pretending to be at location 0, that read 24 bytes into 0-23, then
> executed whatever was read into locaion 8, typically another read command to read
> a disk or tape block with real bootstrap, then started the computer by restoring the status word at
> location 0 which runs the bootstrap just read in to start up the computer.
> 

If it's like the IBM IPL I know... sit down and be prepared to wait 
a-while.  Where I went to uni, the IBM 370/155 took about 20 minutes to 
IPL.  Something about "waiting for the time-base generator to come up to 
speed"  I think...  Power supply voltage levels were involved, and 
sequencing the power-on of equipment to prevent power surges.

'course that's been a *long* time ago for me!!!


-- 

Charles Richmond


-- 
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

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#219153 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	Dan Espen <dan1espen@gmail.com>
Date	2021-09-30 11:03 -0400
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<sj4jji$43o$1@dont-email.me>
In reply to	#219151

Charles Richmond <codescott@aquaporin4.com> writes:

> On 9/29/2021 5:10 PM, John Levine wrote:
>> According to Questor <usenet@only.tnx>:
>>> Circling back to something on topic:  this reminds me of bootstraping
>>> a DEC KI-10.  From memory, subject to errors:  first you set a code
>>> in a switch register that selects which device to use, for example, paper tape,
>>> then push another button.  That loads into memory and executes a small
>>> loader program that reads a bigger bootstrap loader from disk, which in
>>> turn loads and starts the operating system (i.e., the monitor in TOPS-10
>>> parlance).
>> Sounds like S/360.  You set the device number of the IPL (initial
>> program load)
>> device in the switches and pressed the IPL button.  That ran a fixed one instruction
>> channel program pretending to be at location 0, that read 24 bytes into 0-23, then
>> executed whatever was read into locaion 8, typically another read command to read
>> a disk or tape block with real bootstrap, then started the computer by restoring the status word at
>> location 0 which runs the bootstrap just read in to start up the computer.
>> 
>
> If it's like the IBM IPL I know... sit down and be prepared to wait
> a-while.  Where I went to uni, the IBM 370/155 took about 20 minutes
> to IPL.  Something about "waiting for the time-base generator to come
> up to speed"  I think...  Power supply voltage levels were involved,
> and sequencing the power-on of equipment to prevent power surges.
>
> 'course that's been a *long* time ago for me!!!

I think that was characteristic of OS/VS.

DOS and DOS/VS managed a minute or 2.

The IBM 1401 booted just about the same as the other machines mentioned.
Clear 1-80, read a card into 1-80, branch to 1.

Unlike the S/360, I don't remember any way to make a 1401 boot from
other media.

-- 
Dan Espen

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#219165 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	Anne & Lynn Wheeler <lynn@garlic.com>
Date	2021-09-30 09:16 -1000
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<87k0ixc1sf.fsf@localhost>
In reply to	#219153

Dan Espen <dan1espen@gmail.com> writes:
> I think that was characteristic of OS/VS.
>
> DOS and DOS/VS managed a minute or 2.
>
> The IBM 1401 booted just about the same as the other machines mentioned.
> Clear 1-80, read a card into 1-80, branch to 1.
>
> Unlike the S/360, I don't remember any way to make a 1401 boot from
> other media.

CP/67 and VM/370 came up in several seconds. Early on CP/67 (that
carried over to VM/370) for being up 7/24 dark room with no operator.
There was even special handling for system crash, automatically take
dump core image ... and automagically re-ipl and be back up and running.

Also back to days when all IBM mainframes were rented and charges based
on "system meter" reading that ran whenever the CPU and/or any channel
was running ... CP/67 developed special channel programs that let
channel go idle but would immediately wake-up for any characters
arriving on a line ... to reduce offshift, light load costs
(and help encourage leaving system up and available 7x24, also
goes for running w/o an operator/human present).

All activity had to be idle for 400ms before "system meter" would
actually stop running. Note: long after IBM had switched mainframes from
lease/rent to sales ... MVS (VS/2) still had a timer task that woke up
every 400ms (to guarantee that system meter never stopped)

-- 
virtualization experience starting Jan1968, online at home since Mar1970

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#219174 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	Peter Flass <peter_flass@yahoo.com>
Date	2021-09-30 17:43 -0700
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<77869481.654741336.824921.peter_flass-yahoo.com@news.eternal-september.org>
In reply to	#219153

Dan Espen <dan1espen@gmail.com> wrote:
> Charles Richmond <codescott@aquaporin4.com> writes:
> 
>> On 9/29/2021 5:10 PM, John Levine wrote:
>>> According to Questor <usenet@only.tnx>:
>>>> Circling back to something on topic:  this reminds me of bootstraping
>>>> a DEC KI-10.  From memory, subject to errors:  first you set a code
>>>> in a switch register that selects which device to use, for example, paper tape,
>>>> then push another button.  That loads into memory and executes a small
>>>> loader program that reads a bigger bootstrap loader from disk, which in
>>>> turn loads and starts the operating system (i.e., the monitor in TOPS-10
>>>> parlance).
>>> Sounds like S/360.  You set the device number of the IPL (initial
>>> program load)
>>> device in the switches and pressed the IPL button.  That ran a fixed one instruction
>>> channel program pretending to be at location 0, that read 24 bytes into 0-23, then
>>> executed whatever was read into locaion 8, typically another read command to read
>>> a disk or tape block with real bootstrap, then started the computer by
>>> restoring the status word at
>>> location 0 which runs the bootstrap just read in to start up the computer.
>>> 
>> 
>> If it's like the IBM IPL I know... sit down and be prepared to wait
>> a-while.  Where I went to uni, the IBM 370/155 took about 20 minutes
>> to IPL.  Something about "waiting for the time-base generator to come
>> up to speed"  I think...  Power supply voltage levels were involved,
>> and sequencing the power-on of equipment to prevent power surges.
>> 
>> 'course that's been a *long* time ago for me!!!
> 
> I think that was characteristic of OS/VS.
> 
> DOS and DOS/VS managed a minute or 2.
> 
> The IBM 1401 booted just about the same as the other machines mentioned.
> Clear 1-80, read a card into 1-80, branch to 1.
> 
> Unlike the S/360, I don't remember any way to make a 1401 boot from
> other media.
> 

I believe I just read that the IBM 1130 had to be booted from the card
reader. Of china course, since it had core memory it could be powered down
and up without having to to reboot, so I’m not sure I ever experienced
this.

-- 
Pete

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#219180 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	Ahem A Rivet's Shot <steveo@eircom.net>
Date	2021-10-01 06:18 +0100
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<20211001061850.3008e68dc89434fbd28c3081@eircom.net>
In reply to	#219174

On Thu, 30 Sep 2021 17:43:23 -0700
Peter Flass <peter_flass@yahoo.com> wrote:

> I believe I just read that the IBM 1130 had to be booted from the card
> reader. 

	That is correct, the card was punched with a binary that could load
the real boot code from disk. I used it fairly often, the 1130 was an easy
machine for students to crash.

-- 
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/

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#219260 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

From	John Levine <johnl@taugh.com>
Date	2021-10-03 22:45 +0000
Subject	Re: bootstrap, was What is the oldest computer that could be used today for real work?
Message-ID	<sjdbpv$1v05$1@gal.iecc.com>
In reply to	#219174

According to Peter Flass  <peter_flass@yahoo.com>:
>I believe I just read that the IBM 1130 had to be booted from the card
>reader. Of china course, since it had core memory it could be powered down
>and up without having to to reboot, so I’m not sure I ever experienced
>this.

The manual says you could boot it either from the card reader or paper tape,
but I doubt there was ever a paper-tape-only 1130.

-- 
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

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#219034

From	Peter Flass <peter_flass@yahoo.com>
Date	2021-09-25 12:28 -0700
Message-ID	<1505708672.654289929.320687.peter_flass-yahoo.com@news.eternal-september.org>
In reply to	#218984

J. Clarke <jclarke.873638@gmail.com> wrote:
> On 24 Sep 2021 03:10:29 -0300, Mike Spencer
> <mds@bogus.nodomain.nowhere> wrote:
> 
>> 
>> J. Clarke <jclarke.873638@gmail.com> writes:
>> 
>>> On Thu, 23 Sep 2021 18:31:34 GMT, Charlie Gibbs
>>> <cgibbs@kltpzyxm.invalid> wrote:
>>> 
>>>> On 2021-09-23, Scott Lurndal <scott@slp53.sl.home> wrote:
>>>> 
>>>>> Running critical infrastructure on windows should be a criminal offense.
>>>> 
>>>> Hear, hear!
>>> 
>>> That ship, however, has sailed.
>> 
>> AIUI, the US Navy now navigates with Windoes, has for many years.  And
>> in addition has dropped astral navigation skills as a requirement for
>> officers.  Furrfu.
> 
> You do know that a handheld GPS can provide the same information as
> celestial nav, with vastly greater precision, do you not?  And likely
> has accurate charts these days.
> 

Sure, but only, as someone has said, if the satellites are working. Heck,
my iPhone has good GPS.

-- 
Pete

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#219037

From	J. Clarke <jclarke.873638@gmail.com>
Date	2021-09-25 15:56 -0400
Message-ID	<pkvukgpbeg7mb8e98bosil13ighq0u8gkg@4ax.com>
In reply to	#219034

On Sat, 25 Sep 2021 12:28:22 -0700, Peter Flass
<peter_flass@yahoo.com> wrote:

>J. Clarke <jclarke.873638@gmail.com> wrote:
>> On 24 Sep 2021 03:10:29 -0300, Mike Spencer
>> <mds@bogus.nodomain.nowhere> wrote:
>> 
>>> 
>>> J. Clarke <jclarke.873638@gmail.com> writes:
>>> 
>>>> On Thu, 23 Sep 2021 18:31:34 GMT, Charlie Gibbs
>>>> <cgibbs@kltpzyxm.invalid> wrote:
>>>> 
>>>>> On 2021-09-23, Scott Lurndal <scott@slp53.sl.home> wrote:
>>>>> 
>>>>>> Running critical infrastructure on windows should be a criminal offense.
>>>>> 
>>>>> Hear, hear!
>>>> 
>>>> That ship, however, has sailed.
>>> 
>>> AIUI, the US Navy now navigates with Windoes, has for many years.  And
>>> in addition has dropped astral navigation skills as a requirement for
>>> officers.  Furrfu.
>> 
>> You do know that a handheld GPS can provide the same information as
>> celestial nav, with vastly greater precision, do you not?  And likely
>> has accurate charts these days.
>> 
>
>Sure, but only, as someone has said, if the satellites are working. Heck,
>my iPhone has good GPS.

Why would they not be?  There are 100 orbital launches or so a year.
It would take that many to knock down all the satnav satellites.  And
there aren't very many orbital launch facilities in the
world--furthermore none of them are hardened.

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#219039

From	Ahem A Rivet's Shot <steveo@eircom.net>
Date	2021-09-25 22:21 +0100
Message-ID	<20210925222151.589fbe9953eb9c767095fce4@eircom.net>
In reply to	#219037

On Sat, 25 Sep 2021 15:56:30 -0400
J. Clarke <jclarke.873638@gmail.com> wrote:

> Why would they not be?  There are 100 orbital launches or so a year.
> It would take that many to knock down all the satnav satellites.  And
> there aren't very many orbital launch facilities in the
> world--furthermore none of them are hardened.

	This and the possibility that there is a separate constellation for
military use with an authenticated and encrypted protocol and hardened
satellites. It would be easy enough to do and hide and an elementary common
sense precaution and it's really hard to steal a private key if the only
copy is on a satellite.

-- 
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/

[toc] | [prev] | [next] | [standalone]

#219087

From	usenet@only.tnx (Questor)
Date	2021-09-28 13:11 +0000
Message-ID	<61531462.14615996@news.dslextreme.com>
In reply to	#219039

On Sat, 25 Sep 2021 22:21:51 +0100, Ahem A Rivet's Shot <steveo@eircom.net>
wrote:
>On Sat, 25 Sep 2021 15:56:30 -0400
>J. Clarke <jclarke.873638@gmail.com> wrote:
>>Why would they not be?  There are 100 orbital launches or so a year.
>>It would take that many to knock down all the satnav satellites.  And
>>there aren't very many orbital launch facilities in the
>>world--furthermore none of them are hardened.
>
>This and the possibility that there is a separate constellation for
>military use with an authenticated and encrypted protocol and hardened
>satellites. It would be easy enough to do and hide and an elementary common
>sense precaution and it's really hard to steal a private key if the only
>copy is on a satellite.

Easy to do -- perhaps.  Easy to hide?  No.  There are bird watchers, train
spotters, and similarly, people who track satellites.  They have the orbital
characteristics for known commercial and military satellites, and watch for
them.  So-called "black" satellites tend to stand out because when they are
observed from the ground, their orbits don't match any satellites that people
are claiming credit for.

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csiph-web

What is the oldest computer that could be used today for real work?

Contents

#219044

#219047

#219054

#219089

#219086

#219131 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219136 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219149 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219173 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219208 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219151 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219153 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219165 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219174 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219180 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219260 — Re: bootstrap, was What is the oldest computer that could be used today for real work?

#219034

#219037

#219039

#219087