An Xmyth stack overflow ?

[gareth evans]

1972 was my graduation year doing electronics and computing, and,
for our 3rd year projects, one of the guys had special dispensation
from the Uni to spend £3 on an LED. £3 ? ? ? Well, that was my
weekly withdrawal from the bank to cover all my living expenses.

My first computing job that year came with a salary of £1320 pa,
meaning that before tax, I could have blown the lot on 45 LEDs ! :-)

For Xmyth this year, I have 4 strings of multi-coloured LEDs
spread out over the front garden, with a total of about 1000 LEDs
for a total outlay of about £100.

Stack overflow possibly? After one of the strings of LEDs has cycled
through its repertoire a number of times, they all extinguish and
stay dark, but if I cycle the power, they all return, so it isn't
an overheating problem.

[gareth evans]

Post by gareth evans
1972 was my graduation year doing electronics and computing, and,
for our 3rd year projects, one of the guys had special dispensation
from the Uni to spend £3 on an LED. £3 ? ? ? Well, that was my
weekly withdrawal from the bank to cover all my living expenses.
My first computing job that year came with a salary of £1320 pa,
meaning that before tax, I could have blown the lot on 45 LEDs ! :-)
For Xmyth this year, I have 4 strings of multi-coloured LEDs
spread out over the front garden, with a total of about 1000 LEDs
for a total outlay of about £100.
Stack overflow possibly? After one of the strings of LEDs has cycled
through its repertoire a number of times, they all extinguish and
stay dark, but if I cycle the power, they all return, so it isn't
an overheating problem.

Oops 450 LEDs. Time, methinks, to bin this laptop because of
a number of sticking keys, including the , and the ,
and the . :-( :-)

[maus]

Post by gareth evans

Post by gareth evans
1972 was my graduation year doing electronics and computing, and,
for our 3rd year projects, one of the guys had special dispensation
from the Uni to spend £3 on an LED. £3 ? ? ? Well, that was my
weekly withdrawal from the bank to cover all my living expenses.
My first computing job that year came with a salary of £1320 pa,
meaning that before tax, I could have blown the lot on 45 LEDs ! :-)

In my unhumble opinion, tales of money from the past are meaaningless,
like most official data. That time, one had very basic expenses of
almost zero. (Food, and someway of sleeping dry at night, sometimes
ignoring the patter of tiny feet over your face). My first action after
school was about 1957, rent about a couple of quid a week, and weekend
expenses of about ten shillings,

Getting married changed everything. The expenses of a house, etc, means
that a better job is needed, and such jobs are usually very boring.

Post by gareth evans

Post by gareth evans
For Xmyth this year, I have 4 strings of multi-coloured LEDs
spread out over the front garden, with a total of about 1000 LEDs
for a total outlay of about £100.
Stack overflow possibly? After one of the strings of LEDs has cycled
through its repertoire a number of times, they all extinguish and
stay dark, but if I cycle the power, they all return, so it isn't
an overheating problem.

Oops 450 LEDs. Time, methinks, to bin this laptop because of
a number of sticking keys, including the , and the ,
and the . :-( :-)

The Chaos group in Germany had members interested in such things, from
illuminating the windows of large buildings to form text messages, down
to what you mention. Their meetings are in Leipzig this year.
a

[maus]

Post by maus

Post by gareth evans
1972 was my graduation year doing electronics and computing, and,
for our 3rd year projects, one of the guys had special dispensation
from the Uni to spend £3 on an LED. £3 ? ? ? Well, that was my
weekly withdrawal from the bank to cover all my living expenses.
My first computing job that year came with a salary of £1320 pa,
meaning that before tax, I could have blown the lot on 45 LEDs ! :-)

In my unhumble opinion, tales of money from the past are meaaningless,
like most official data. That time, one had very basic expenses of
almost zero. (Food, and someway of sleeping dry at night, sometimes
ignoring the patter of tiny feet over your face). My first action after
school was about 1957, rent about a couple of quid a week, and weekend
expenses of about ten shillings,

Further thought. After my recent stay in hospital (think `One flew over
the cuckoo's nest' except it was a general hospital.), I returned home
to find that the family had `cleaned up'. I had to get a computer, and
go a one about 10 years old (no EFI). Now I have come to the confusion
that computers (general) have not improved in almost 10 years, which
would almost bring this subject into topic for this group.

I would think that docbooks are a sorta subcomputers.

[Dave Garland]

Post by maus
After my recent stay in hospital (think `One flew over
the cuckoo's nest' except it was a general hospital.), I returned home
to find that the family had `cleaned up'. I had to get a computer, and
go a one about 10 years old (no EFI). Now I have come to the confusion
that computers (general) have not improved in almost 10 years, which
would almost bring this subject into topic for this group.

Of course it depends on what you're using them for. They've got more
CPU cores, more RAM, bigger HDs. But for the average user who doesn't
play modern games, not much. I was doing video editing on a 10 year
old computer just fine. (I now have a 6 year old one, purchased at a
thrift store, since I no longer have a stable of clients to scrounge
throwaways from.) More RAM than 4GB helps (I no longer get disk
thrashing if I open too many browser tabs).

Then again, I remember my first MSDOS computer (a Sperry nee Corona),
and telling people that a 10M HDD was all anybody needed if they had
any discipline at all. The 1TB HDD on my last computer was getting
full, mostly because it was a PITA to back up all the video production
stuff (that I'll probably never want again).

Post by maus
I would think that docbooks are a sorta subcomputers.

Oh hell, my 4 year old Android phone is a more powerful computer than
the mainframe (an IBM1620) that my college had. Though the
blinkenlights are much inferior.

[Mike Spencer]

Post by Dave Garland
Oh hell, my 4 year old Android phone is a more powerful computer than
the mainframe (an IBM1620) that my college had. Though the
blinkenlights are much inferior.

Yeah, my uni had a 1620 to which we lowly Fortran 101 undergrads could
submit card decks. 48K of core memory with the optional expansion
IIRC. And the blinkenlight were over there --> behind the railing.

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.) I'd love to take an Osborne I back
to the 1964 class, plunk it downin front of the guy who wanted to
teach us numerical methods instead of Fortran and show him, say,
Conway's LIFE in C.

[Ahem A Rivet's Shot]

On 11 Dec 2020 01:47:02 -0400

Post by Mike Spencer
I'd love to take an Osborne I back
to the 1964 class, plunk it downin front of the guy who wanted to
teach us numerical methods instead of Fortran

Some 15 years later, when I took Computer Science, FORTRAN was a
three day course, after which we wrote a comparison of FORTRAN II and
FORTRAN IV never to use it again, while numerical methods was a full term of
lectures.

[Bob Eager]

Post by Ahem A Rivet's Shot

I'd love to take an Osborne I back to the 1964 class, plunk it downin
front of the guy who wanted to teach us numerical methods instead of
Fortran

Some 15 years later, when I took Computer Science, FORTRAN was a
three day course, after which we wrote a comparison of FORTRAN II and
FORTRAN IV never to use it again, while numerical methods was a full
term of lectures.

I learned BASIC 50 years ago (give or take a month).

I obviously got interested, and looked around for something else. The
local preference was ALGOL, so being me I self taught FORTRAN IV. This
was useful a few times much later, but it was fairly boring. So I learned
assembler on the ICL 4130 - 24 bit machine with 32kW of memory. Probably
about 200 kips.

Interestingly, FORTRAN was an afterthought on that system, and didn't
integrate very well. It obviously only ran in batch (cards to printer).
If the batch system detected a FORTRAN job, it unloaded most of itself
(device interfaces excluded) and loaded a different batch executive. This
was reversed if a non FORTRAN job was encountered.

The switch (using a program called SWAP!) too about 3 seconds, I think (I
was in the machine room a few years later and actually heard the disks
clicking with the changeover). Because of this, we had to put the FORTRAN-
or-not status on the job cards so that the operators could optimise by
grouping FORTRAN jobs together.

That machine didn't have much more in the way of languages until I wrote
a BCPL compiler for it.

[John Levine]

Post by Mike Spencer
I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

[Gerard Schildberger]

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.
--
Regards,
John Levine

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was just
a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.
____________________________________________________ Gerard Schildberger

[Charlie Gibbs]

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

I do love the cleverness of that CADET back-formation, though...

[John Levine]

Post by Charlie Gibbs

Post by Gerard Schildberger
The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

In this case it wasn't a matter of crippling the performance, it was a
desire to kill of all of the old incompatible product lines. There was
an option for the 360/30 to emulate a 1620 but I don't think it was
very popular.

Shortly after the 360 series came out, IBM added the 1130, a 16 bit
binary machine that wasn't compatible with anything. It was pretty
slow, but it was a lot faster than a 1620 and came with a standard
disk drive. Its software used the 360's 8-bit EBCDIC code.

For the real-time customers, there was the 1800, a souped
up 1130, and the 360/44, an odd stripped down 360 that ran floating
point fairly fast and had some realtime interface features.

[Peter Flass]

Post by John Levine

Post by Charlie Gibbs

Post by Gerard Schildberger
The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

In this case it wasn't a matter of crippling the performance, it was a
desire to kill of all of the old incompatible product lines. There was
an option for the 360/30 to emulate a 1620 but I don't think it was
very popular.

Not sure I ever heard of this. In any case I don’t have any 1620 code I
would want to run any more.

Post by John Levine
Shortly after the 360 series came out, IBM added the 1130, a 16 bit
binary machine that wasn't compatible with anything. It was pretty
slow, but it was a lot faster than a 1620 and came with a standard
disk drive. Its software used the 360's 8-bit EBCDIC code.

I loved the 1130. Looking at it now it’s obvious that it’s architecture
wouldn’t allow it to be extended much.

Post by John Levine
For the real-time customers, there was the 1800, a souped
up 1130, and the 360/44, an odd stripped down 360 that ran floating
point fairly fast and had some realtime interface features.

I’m sorry I never saw a /44 in the wild. It must have been a fun machine.
It would be fun to modify Hercules to support it, mostly a matter of
stripping out instructions - I think there only about five unique
instructions.

[John Levine]

Post by John Levine
up 1130, and the 360/44, an odd stripped down 360 that ran floating
point fairly fast and had some realtime interface features.

I’m sorry I never saw a /44 in the wild. It must have been a fun machine.
It would be fun to modify Hercules to support it, mostly a matter of
stripping out instructions - I think there only about five unique
instructions.

It had a knob on the front panel to control floating point precsion
and some unique peripherals, notably a one-platter disk drive that
looks to be the same as the 1130's. I never used one but somehow ended
up with a set of manuals.

[Peter Flass]

Post by John Levine

Post by Peter Flass

Post by John Levine
up 1130, and the 360/44, an odd stripped down 360 that ran floating
point fairly fast and had some realtime interface features.

I’m sorry I never saw a /44 in the wild. It must have been a fun machine.
It would be fun to modify Hercules to support it, mostly a matter of
stripping out instructions - I think there only about five unique
instructions.

It had a knob on the front panel to control floating point precsion
and some unique peripherals, notably a one-platter disk drive that
looks to be the same as the 1130's. I never used one but somehow ended
up with a set of manuals.

Does Bitsavers have them? I know they have some /44 stuff. I fo believe the
disk was the same as the 1130. A second drive was an option, but the job of
the first was system residence.

[J. Clarke]

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

I am curious as to the nature of this crippling.

Post by Charlie Gibbs
I do love the cleverness of that CADET back-formation, though...

[Dave Garland]

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

It's a different market. While you could get CP/M-86 and UCSD p-System
for the D'wr (pre-IBM PC), I think it had a 1MHz CPU and CP/M-86 at
least was very sluggish compared to a 4MHz Osborne O-1. But our D'wrs
had more RAM and could run a bigger SuperCalc spreadsheet
(sluggishly). When we did that, the challenge was making the printer
work. IBM did its classic routine, being unfailingly polite and
switching me from one person who couldn't tell me what the control
codes were to another until I gave up and did it by trial and error.

IBM later sold "Displaywrite" softwere for the PC that emulated a lot
of the software features.

[Peter Flass]

Post by Dave Garland

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

It's a different market. While you could get CP/M-86 and UCSD p-System
for the D'wr (pre-IBM PC), I think it had a 1MHz CPU and CP/M-86 at
least was very sluggish compared to a 4MHz Osborne O-1. But our D'wrs
had more RAM and could run a bigger SuperCalc spreadsheet
(sluggishly). When we did that, the challenge was making the printer
work. IBM did its classic routine, being unfailingly polite and
switching me from one person who couldn't tell me what the control
codes were to another until I gave up and did it by trial and error.
IBM later sold "Displaywrite" softwere for the PC that emulated a lot
of the software features.

The display on the Displaywriter was high-quality. Going from a real
Displaywriter to Displaywrite on a PC was a big step backwards for anyone
who did a lot of word processing.

[J. Clarke]

On Sat, 12 Dec 2020 06:58:19 -0700, Peter Flass

Post by Peter Flass

Post by Dave Garland

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

It's a different market. While you could get CP/M-86 and UCSD p-System
for the D'wr (pre-IBM PC), I think it had a 1MHz CPU and CP/M-86 at
least was very sluggish compared to a 4MHz Osborne O-1. But our D'wrs
had more RAM and could run a bigger SuperCalc spreadsheet
(sluggishly). When we did that, the challenge was making the printer
work. IBM did its classic routine, being unfailingly polite and
switching me from one person who couldn't tell me what the control
codes were to another until I gave up and did it by trial and error.
IBM later sold "Displaywrite" softwere for the PC that emulated a lot
of the software features.

The display on the Displaywriter was high-quality. Going from a real
Displaywriter to Displaywrite on a PC was a big step backwards for anyone
who did a lot of word processing.

What was "high quality" about the monitor? I did hear a lot of
kvetching about the PC display back then but generally the people
kvetching got the color display instead of the green screen.

[Dan Espen]

Post by J. Clarke
On Sat, 12 Dec 2020 06:58:19 -0700, Peter Flass

Post by Peter Flass

Post by Dave Garland

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

It's a different market. While you could get CP/M-86 and UCSD p-System
for the D'wr (pre-IBM PC), I think it had a 1MHz CPU and CP/M-86 at
least was very sluggish compared to a 4MHz Osborne O-1. But our D'wrs
had more RAM and could run a bigger SuperCalc spreadsheet
(sluggishly). When we did that, the challenge was making the printer
work. IBM did its classic routine, being unfailingly polite and
switching me from one person who couldn't tell me what the control
codes were to another until I gave up and did it by trial and error.
IBM later sold "Displaywrite" softwere for the PC that emulated a lot
of the software features.

The display on the Displaywriter was high-quality. Going from a real
Displaywriter to Displaywrite on a PC was a big step backwards for anyone
who did a lot of word processing.

What was "high quality" about the monitor? I did hear a lot of
kvetching about the PC display back then but generally the people
kvetching got the color display instead of the green screen.

Bitsavers says there were 2 displays available, 80x25 and 64x100,
both monochrome.

I don't see the resolution, but the screen shots on the 80x25 look
pretty clear, at least as good as the PC/3270. I think 64x100 would
out-do most PCs for a while. By the time I saw my first PC/3270 it was
full color, better than the DisplayWriter.

I remember the first PC displays were pretty poor resolution wise.
If you wanted to really see things you went with the monochrome
Hercules. (Never saw one of those.)

[Ahem A Rivet's Shot]

On Sat, 12 Dec 2020 10:31:57 -0500

Post by Dan Espen
I remember the first PC displays were pretty poor resolution wise.
If you wanted to really see things you went with the monochrome
Hercules. (Never saw one of those.)

The first PC displays were either a high quality but long
persistence green screen attached to an MDA providing 80x25 text only or a
CGA adaptor which was *awful* low resolution graphics (even for the time)
and flickery.

[Charlie Gibbs]

Post by Ahem A Rivet's Shot
On Sat, 12 Dec 2020 10:31:57 -0500

Post by Dan Espen
I remember the first PC displays were pretty poor resolution wise.
If you wanted to really see things you went with the monochrome
Hercules. (Never saw one of those.)

The first PC displays were either a high quality but long
persistence green screen attached to an MDA providing 80x25 text only or a
CGA adaptor which was *awful* low resolution graphics (even for the time)
and flickery.

Not to mention slow. When a PPOE bought its first batch of
IBM PC clones, they all came with CGA because everyone wanted
pretty colours. But they were so slow that when running a
word processor (the most common application) a good typist
(myself included) could stay a word ahead of the display.
We eventually replaced the CGAs in all the machines except
the one that needed graphics, with Hercules - which were
both razor-sharp and fast.

[J. Clarke]

Post by Dan Espen

Post by J. Clarke
On Sat, 12 Dec 2020 06:58:19 -0700, Peter Flass

Post by Peter Flass

Post by Dave Garland

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

It's a different market. While you could get CP/M-86 and UCSD p-System
for the D'wr (pre-IBM PC), I think it had a 1MHz CPU and CP/M-86 at
least was very sluggish compared to a 4MHz Osborne O-1. But our D'wrs
had more RAM and could run a bigger SuperCalc spreadsheet
(sluggishly). When we did that, the challenge was making the printer
work. IBM did its classic routine, being unfailingly polite and
switching me from one person who couldn't tell me what the control
codes were to another until I gave up and did it by trial and error.
IBM later sold "Displaywrite" softwere for the PC that emulated a lot
of the software features.

The display on the Displaywriter was high-quality. Going from a real
Displaywriter to Displaywrite on a PC was a big step backwards for anyone
who did a lot of word processing.

What was "high quality" about the monitor? I did hear a lot of
kvetching about the PC display back then but generally the people
kvetching got the color display instead of the green screen.

Bitsavers says there were 2 displays available, 80x25 and 64x100,
both monochrome.
I don't see the resolution, but the screen shots on the 80x25 look
pretty clear, at least as good as the PC/3270. I think 64x100 would
out-do most PCs for a while. By the time I saw my first PC/3270 it was
full color, better than the DisplayWriter.
I remember the first PC displays were pretty poor resolution wise.
If you wanted to really see things you went with the monochrome
Hercules. (Never saw one of those.)

If that was your experience I can understand why you thought PCs were
crippled. The IBM CGA had graphics capability but not a lot of
resolution. The IBM "Black and White" (actually dark gray and green)
display was for the day very sharp but had no graphics capability.
What Hercules brought to the table was graphics on the black and white
display.

I've never actually used a machine with the CGA except where it had a
black and white as well.

[Dan Espen]

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

[J. Clarke]

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

[Dan Espen]

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

Yep, just turned 75.
It's embarrassing the number of things I forget, get wrong, can't find,
etc. I installed a new garage door opener a few days ago. I kept
dropping parts and then I couldn't find them. A 2 hour job that took me 4.

I lift weights and still have the physique of a youngster so I still
have that going for me.

[J. Clarke]

Post by Dan Espen

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

Yep, just turned 75.
It's embarrassing the number of things I forget, get wrong, can't find,
etc. I installed a new garage door opener a few days ago. I kept
dropping parts and then I couldn't find them. A 2 hour job that took me 4.
I lift weights and still have the physique of a youngster so I still
have that going for me.

Another habit to workon. I have the physique of a potato. The thing
that's annoying me is that I am starting to go blank on nomenclature.
Takes me many repetitions to get down things like "trailer record"
(data sciency term for a checksum apparently--why can't they just call
it that). I know what it is, I have no trouble writing the code to
produce it, but I can't remember the damned term when I'm talking to
somebody about it.

[Dan Espen]

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

Yep, just turned 75.
It's embarrassing the number of things I forget, get wrong, can't find,
etc. I installed a new garage door opener a few days ago. I kept
dropping parts and then I couldn't find them. A 2 hour job that took me 4.
I lift weights and still have the physique of a youngster so I still
have that going for me.

Another habit to workon. I have the physique of a potato. The thing
that's annoying me is that I am starting to go blank on nomenclature.
Takes me many repetitions to get down things like "trailer record"
(data sciency term for a checksum apparently--why can't they just call
it that). I know what it is, I have no trouble writing the code to
produce it, but I can't remember the damned term when I'm talking to
somebody about it.

Oh yes, I definitely struggle with that.
I like to grow plants, I have 7/8ths of an acre to work with.
Plant names are really hard to pull out of memory.
I put in a Crepe Myrtle many years back and when it's flowering people ask
me what it is. I must have told a dozen people I can't remember.
So, I think I finally have the Crepe Myrtle down, but I've thought
that before and had it just slip right out.

As for the potato, so many people struggle with that.
I had a _little_ extra weight on in my 40s and 60s, but
I'm back in good shape now. It mainly takes self control
and determination. Both are free.

I always felt weight training should be a required course.
Its something you can do that is proven to improve your health,
unlike "healthy eating", vitamins, and other fads.

Trailer records? Those were the cards you punched with totals
to put behind the header records and detail records.

[Dan Espen]

...

Post by Dan Espen

Post by J. Clarke
The thing
that's annoying me is that I am starting to go blank on nomenclature.

Oh yes, I definitely struggle with that.

Yes, replying to myself.

I'm just looking at Slashdot and I see a link to this:

https://www.ucsf.edu/news/2020/12/419201/drug-reverses-age-related-mental-decline-within-days

Just a few doses of an experimental drug can reverse age-related
declines in memory and mental flexibility in mice,


So, I already know how to keep myself in good physical shape, this pill
is going to keep the brain going...I might be haunting this newsgroup
for a long time.

[Peter Flass]

Post by Dan Espen
...

Post by Dan Espen

Post by J. Clarke
The thing
that's annoying me is that I am starting to go blank on nomenclature.

Oh yes, I definitely struggle with that.

Yes, replying to myself.
https://www.ucsf.edu/news/2020/12/419201/drug-reverses-age-related-mental-decline-within-days
Just a few doses of an experimental drug can reverse age-related
declines in memory and mental flexibility in mice,
So, I already know how to keep myself in good physical shape, this pill
is going to keep the brain going...I might be haunting this newsgroup
for a long time.

I saw that too.i’m excited. The first time I read the article I got the
impression the drug was already approved for other things, so it would be
possible to get off-label access now. I re-read the article and it appears
I was mistaken.

Apparently this thing might REVERSE the effects of Alzheimers and Dementia
(not just slow progression) and help with TBI also. If so, I hope they
approve it soon, since these things are becoming very big problems for
society (assuming we all don’t die of COVID first).

[Dan Espen]

Post by Peter Flass

Post by Dan Espen
...

Post by Dan Espen

Post by J. Clarke
The thing
that's annoying me is that I am starting to go blank on nomenclature.

Oh yes, I definitely struggle with that.

Yes, replying to myself.
https://www.ucsf.edu/news/2020/12/419201/drug-reverses-age-related-mental-decline-within-days
Just a few doses of an experimental drug can reverse age-related
declines in memory and mental flexibility in mice,
So, I already know how to keep myself in good physical shape, this pill
is going to keep the brain going...I might be haunting this newsgroup
for a long time.

I saw that too.i’m excited. The first time I read the article I got the
impression the drug was already approved for other things, so it would be
possible to get off-label access now. I re-read the article and it appears
I was mistaken.
Apparently this thing might REVERSE the effects of Alzheimers and Dementia
(not just slow progression) and help with TBI also. If so, I hope they
approve it soon, since these things are becoming very big problems for
society (assuming we all don’t die of COVID first).

I read the Slashdot discussion. They think this is an organic
chemical with a known formula. Anyone can get it.

Sure does sound like a wonder drug, we'll see.

[J. Clarke]

Post by Dan Espen
...

Post by Dan Espen

Post by J. Clarke
The thing
that's annoying me is that I am starting to go blank on nomenclature.

Oh yes, I definitely struggle with that.

Yes, replying to myself.
https://www.ucsf.edu/news/2020/12/419201/drug-reverses-age-related-mental-decline-within-days
Just a few doses of an experimental drug can reverse age-related
declines in memory and mental flexibility in mice,
So, I already know how to keep myself in good physical shape, this pill
is going to keep the brain going...I might be haunting this newsgroup
for a long time.

Man, I _want_ some of that stuff. Corrects noise related hearing
loss? I lost my highs in the '60s--fortunately my boss is an alto,
but some of the women I work with I just plain can't hear.

[Dan Espen]

Post by J. Clarke

Post by Dan Espen
...

Post by Dan Espen

Post by J. Clarke
The thing
that's annoying me is that I am starting to go blank on nomenclature.

Oh yes, I definitely struggle with that.

Yes, replying to myself.
https://www.ucsf.edu/news/2020/12/419201/drug-reverses-age-related-mental-decline-within-days
Just a few doses of an experimental drug can reverse age-related
declines in memory and mental flexibility in mice,
So, I already know how to keep myself in good physical shape, this pill
is going to keep the brain going...I might be haunting this newsgroup
for a long time.

Man, I _want_ some of that stuff. Corrects noise related hearing
loss? I lost my highs in the '60s--fortunately my boss is an alto,
but some of the women I work with I just plain can't hear.

Same here.
Got those hearing aids that fit entirely in the ear.
Still have problems hearing some women.

[maus]

Post by J. Clarke

Post by Dan Espen
...

Post by Dan Espen

Post by J. Clarke
The thing
that's annoying me is that I am starting to go blank on nomenclature.

Oh yes, I definitely struggle with that.

Yes, replying to myself.
https://www.ucsf.edu/news/2020/12/419201/drug-reverses-age-related-mental-decline-within-days
Just a few doses of an experimental drug can reverse age-related
declines in memory and mental flexibility in mice,
So, I already know how to keep myself in good physical shape, this pill
is going to keep the brain going...I might be haunting this newsgroup
for a long time.

Man, I _want_ some of that stuff. Corrects noise related hearing
loss? I lost my highs in the '60s--fortunately my boss is an alto,
but some of the women I work with I just plain can't hear.

Very diplomatic!

[J. Clarke]

Post by Dan Espen

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

Yep, just turned 75.
It's embarrassing the number of things I forget, get wrong, can't find,
etc. I installed a new garage door opener a few days ago. I kept
dropping parts and then I couldn't find them. A 2 hour job that took me 4.
I lift weights and still have the physique of a youngster so I still
have that going for me.

Another habit to workon. I have the physique of a potato. The thing
that's annoying me is that I am starting to go blank on nomenclature.
Takes me many repetitions to get down things like "trailer record"
(data sciency term for a checksum apparently--why can't they just call
it that). I know what it is, I have no trouble writing the code to
produce it, but I can't remember the damned term when I'm talking to
somebody about it.

Oh yes, I definitely struggle with that.
I like to grow plants, I have 7/8ths of an acre to work with.
Plant names are really hard to pull out of memory.
I put in a Crepe Myrtle many years back and when it's flowering people ask
me what it is. I must have told a dozen people I can't remember.
So, I think I finally have the Crepe Myrtle down, but I've thought
that before and had it just slip right out.
As for the potato, so many people struggle with that.
I had a _little_ extra weight on in my 40s and 60s, but
I'm back in good shape now. It mainly takes self control
and determination. Both are free.
I always felt weight training should be a required course.
Its something you can do that is proven to improve your health,
unlike "healthy eating", vitamins, and other fads.
Trailer records? Those were the cards you punched with totals
to put behind the header records and detail records.

Yeah, pretty much. They're asking for a record count and sums on a a
couple of fields. I get to pick the fields. Of course to do this I
have to modify a program that somebody wrote in C transliterated from
spaghetti Fortran (yes, you really _can_ write Fortran in any
language).

[Peter Flass]

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

Yep, just turned 75.
It's embarrassing the number of things I forget, get wrong, can't find,
etc. I installed a new garage door opener a few days ago. I kept
dropping parts and then I couldn't find them. A 2 hour job that took me 4.
I lift weights and still have the physique of a youngster so I still
have that going for me.

Another habit to workon. I have the physique of a potato. The thing
that's annoying me is that I am starting to go blank on nomenclature.
Takes me many repetitions to get down things like "trailer record"
(data sciency term for a checksum apparently--why can't they just call
it that). I know what it is, I have no trouble writing the code to
produce it, but I can't remember the damned term when I'm talking to
somebody about it.

And here I thought I was the only one. I need to get out more.

[Charlie Gibbs]

Post by Peter Flass

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

Yep, just turned 75.
It's embarrassing the number of things I forget, get wrong, can't find,
etc. I installed a new garage door opener a few days ago. I kept
dropping parts and then I couldn't find them. A 2 hour job that took me 4.
I lift weights and still have the physique of a youngster so I still
have that going for me.

Another habit to workon. I have the physique of a potato. The thing
that's annoying me is that I am starting to go blank on nomenclature.
Takes me many repetitions to get down things like "trailer record"
(data sciency term for a checksum apparently--why can't they just call
it that). I know what it is, I have no trouble writing the code to
produce it, but I can't remember the damned term when I'm talking to
somebody about it.

And here I thought I was the only one. I need to get out more.

+1 - and I'm only 70. But my wife and I try to keep active, both
by walking and cycling (we rode 18 km yesterday, although that is
exceptional). I find that cycling is good for what's left of my knees.

I occasionally blank on things myself, although I do enough things
(flying, music, programming) that exercise my brain, so I'm not too
worried. I can pass the hearing portion of my medical exam, but
I have trouble picking a voice out of background noise, or hearing
someone two rooms away. If only people wouldn't _mumble_!

BTW I'm the one who made the original crack about the IBM Personal
Computer being crippled (8088, 640K barrier, crappy serial port
support, etc.). In 1985 I was programming on a 6-MHZ Z80 box
running TurboDOS - it ran rings around an IBM PC (although
memory was tight).

[J. Clarke]

Post by Charlie Gibbs

Post by Peter Flass

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke

Post by Dan Espen

Post by J. Clarke
If that was your experience I can understand why you thought PCs were
crippled.

Well, I did butt into this thread but it wasn't me making that claim.

I should pay more attention to attributions. I should pay more
attention to a lot of things, but I'm reaching an age where changing
habits is a lost cause.

Yep, just turned 75.
It's embarrassing the number of things I forget, get wrong, can't find,
etc. I installed a new garage door opener a few days ago. I kept
dropping parts and then I couldn't find them. A 2 hour job that took me 4.
I lift weights and still have the physique of a youngster so I still
have that going for me.

Another habit to workon. I have the physique of a potato. The thing
that's annoying me is that I am starting to go blank on nomenclature.
Takes me many repetitions to get down things like "trailer record"
(data sciency term for a checksum apparently--why can't they just call
it that). I know what it is, I have no trouble writing the code to
produce it, but I can't remember the damned term when I'm talking to
somebody about it.

And here I thought I was the only one. I need to get out more.

+1 - and I'm only 70. But my wife and I try to keep active, both
by walking and cycling (we rode 18 km yesterday, although that is
exceptional). I find that cycling is good for what's left of my knees.
I occasionally blank on things myself, although I do enough things
(flying, music, programming) that exercise my brain, so I'm not too
worried. I can pass the hearing portion of my medical exam, but
I have trouble picking a voice out of background noise, or hearing
someone two rooms away. If only people wouldn't _mumble_!
BTW I'm the one who made the original crack about the IBM Personal
Computer being crippled (8088, 640K barrier, crappy serial port
support, etc.). In 1985 I was programming on a 6-MHZ Z80 box
running TurboDOS - it ran rings around an IBM PC (although
memory was tight).

I found that it depended on what you were doing. Wordstar on the PC
simply did not work, not because of anything inherent in the PC but
because the developers didn't do a proper port. Word, Multimate, etc
all worked much better.

[Ahem A Rivet's Shot]

On 13 Dec 2020 16:23:54 GMT

Post by Charlie Gibbs
BTW I'm the one who made the original crack about the IBM Personal
Computer being crippled (8088, 640K barrier, crappy serial port
support, etc.). In 1985 I was programming on a 6-MHZ Z80 box
running TurboDOS - it ran rings around an IBM PC (although
memory was tight).

About the same time I was running database applications on a 6MHz
Z80 box with 256K of bank switched memory. I had the CP/M port of MDBS-III
running in one TPA with a tiny application that just pulled parameters from
the shared space and put results back up there while the real application
ran in another TPA. It outperformed the MS-DOS version running on a PC by
quite a bit (we benchmarked it when they tried to sell us on switching to
PCs - we weren't interested in single user systems and neither were our
customers).

[Peter Flass]

Post by Ahem A Rivet's Shot
On 13 Dec 2020 16:23:54 GMT

Post by Charlie Gibbs
BTW I'm the one who made the original crack about the IBM Personal
Computer being crippled (8088, 640K barrier, crappy serial port
support, etc.). In 1985 I was programming on a 6-MHZ Z80 box
running TurboDOS - it ran rings around an IBM PC (although
memory was tight).

About the same time I was running database applications on a 6MHz
Z80 box with 256K of bank switched memory. I had the CP/M port of MDBS-III
running in one TPA with a tiny application that just pulled parameters from
the shared space and put results back up there while the real application
ran in another TPA. It outperformed the MS-DOS version running on a PC by
quite a bit (we benchmarked it when they tried to sell us on switching to
PCs - we weren't interested in single user systems and neither were our
customers).

TPA??

[Christian Brunschen]

[ ... ] I had the CP/M port of MDBS-III
running in one TPA with a tiny application that just pulled parameters from
the shared space and put results back up there while the real application
ran in another TPA.

[...]

TPA??

In CP/M, at least, the 'TPA' was the 'Transient Program Area',
see https://en.wikipedia.org/wiki/CP/M#Transient_Program_Area - essentially
the actual working RAM available to running software, the address
space that was not in use by CP/M or the hardware in some fashion.

--
Pete

// Christian

[Ahem A Rivet's Shot]

On Sun, 13 Dec 2020 15:11:16 -0700

TPA??

Transient Program Area.

[Niklas Karlsson]

Post by Dan Espen
I remember the first PC displays were pretty poor resolution wise.
If you wanted to really see things you went with the monochrome
Hercules. (Never saw one of those.)

My father's business did CAD in Hercules for a while. I remember it as
quite nice for the time.

Niklas

[Peter Flass]

Post by J. Clarke
On Sat, 12 Dec 2020 06:58:19 -0700, Peter Flass

Post by Peter Flass

Post by Dave Garland

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

It's a different market. While you could get CP/M-86 and UCSD p-System
for the D'wr (pre-IBM PC), I think it had a 1MHz CPU and CP/M-86 at
least was very sluggish compared to a 4MHz Osborne O-1. But our D'wrs
had more RAM and could run a bigger SuperCalc spreadsheet
(sluggishly). When we did that, the challenge was making the printer
work. IBM did its classic routine, being unfailingly polite and
switching me from one person who couldn't tell me what the control
codes were to another until I gave up and did it by trial and error.
IBM later sold "Displaywrite" softwere for the PC that emulated a lot
of the software features.

The display on the Displaywriter was high-quality. Going from a real
Displaywriter to Displaywrite on a PC was a big step backwards for anyone
who did a lot of word processing.

What was "high quality" about the monitor? I did hear a lot of
kvetching about the PC display back then but generally the people
kvetching got the color display instead of the green screen.

Hard to recall, but I think the resolution was a lot better. Of course, it
was text-only, but I seem to recall you couldn’t see the pixels in the
characters.

[Dave Garland]

Post by Peter Flass

Post by J. Clarke
On Sat, 12 Dec 2020 06:58:19 -0700, Peter Flass

Post by Peter Flass

Post by Dave Garland

Post by Charlie Gibbs

Post by Gerard Schildberger

Post by John Levine

I think my Osborne I was more powerful than the IBM 1620. (Serious
tecnology wonks may correct me.)

No doubt. The IBM 1620 was known as CADET for Can't Add, Doesn't Even
Try. It was a decimal serial machine and did all arithmetic by table
lookup. Each instruction took 100us or more. Nonetheless, it was
reliable and fast enough that it was used as part of the IBM 1710
which was the first real time process control system.

The above reply applies to the IBM 1620 Model I (one).
The word "CADET" was the code name before the first delivery, it was
just a code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just names.
The model II (two) didn't use lookup tables except for multiplication.
Model III was about to go into production, but was cancelled because of
the upcoming IBM 360, and IBM didn't want anything to compete with the
360, even other IBM computers.

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.

It's a different market. While you could get CP/M-86 and UCSD p-System
for the D'wr (pre-IBM PC), I think it had a 1MHz CPU and CP/M-86 at
least was very sluggish compared to a 4MHz Osborne O-1. But our D'wrs
had more RAM and could run a bigger SuperCalc spreadsheet
(sluggishly). When we did that, the challenge was making the printer
work. IBM did its classic routine, being unfailingly polite and
switching me from one person who couldn't tell me what the control
codes were to another until I gave up and did it by trial and error.
IBM later sold "Displaywrite" softwere for the PC that emulated a lot
of the software features.

The display on the Displaywriter was high-quality. Going from a real
Displaywriter to Displaywrite on a PC was a big step backwards for anyone
who did a lot of word processing.

What was "high quality" about the monitor? I did hear a lot of
kvetching about the PC display back then but generally the people
kvetching got the color display instead of the green screen.

Hard to recall, but I think the resolution was a lot better. Of course, it
was text-only, but I seem to recall you couldn’t see the pixels in the
characters.

Correct. The D'wr monitor was text-only and not very big, but razor
sharp. Text included some symbols and special characters for major
Roman-alphabet languages (accents etc.). (You could configure the
keyboard for the languages, and it had a caps-lock key that worked
just like a typewriter and stayed down when engaged.) PCs with CGA
weren't much use to a good typist, between the lag and the eyestrain.
Hercules was pretty good.

[Mike Spencer]

Post by Charlie Gibbs

The above reply applies to the IBM 1620 Model I (one). The word
"CADET" was the code name before the first delivery, it was just a
code word; almost all IBM hardware had a code name assigned to it
during design/production before the first delivery. They were just
names. The model II (two) didn't use lookup tables except for
multiplication.
[snip]

Sounds familiar, like the way the original IBM Personal Computer
was crippled so as not to compete with the Displaywriter.
I do love the cleverness of that CADET back-formation, though...

Digressing to arbitrary code names, I've always thought that, having
released a system called XP, Microsoft's next system might reasonably
have been expected to be called JHVH.

Voice: Where do you want to go today?
Choir: Confutatis maledictis, flammis acribus addictis

-- from Mozart's Requiem
-- Microsoft TV ad

[gareth evans]

Post by Dave Garland
Oh hell, my 4 year old Android phone is a more powerful computer than
the mainframe (an IBM1620) that my college had. Though the blinkenlights
are much inferior.

Went up to Essex Uni in 1969 and their mainframe
was in the ICL1900 series.

When I left in 1972 it was a PDP10.

I wonder what they have now, nearly 50 years on?

[Peter Flass]

Post by gareth evans

Post by Dave Garland
Oh hell, my 4 year old Android phone is a more powerful computer than
the mainframe (an IBM1620) that my college had. Though the blinkenlights
are much inferior.

Went up to Essex Uni in 1969 and their mainframe
was in the ICL1900 series.
When I left in 1972 it was a PDP10.
I wonder what they have now, nearly 50 years on?

Probably don’t have a mainframe, but if they did it wouldn’t be as nice a
machine as the PDP-10.

[John Levine]

Post by gareth evans

Post by Dave Garland
Oh hell, my 4 year old Android phone is a more powerful computer than
the mainframe (an IBM1620) that my college had. Though the blinkenlights
are much inferior.

Went up to Essex Uni in 1969 and their mainframe
was in the ICL1900 series.
When I left in 1972 it was a PDP10.
I wonder what they have now, nearly 50 years on?

A bunch of Windows and Linux boxes, like everyone else:

https://www.essex.ac.uk/departments/computer-science-and-electronic-engineering/facilities

[Bob Eager]

Post by Peter Flass

Post by Dave Garland
Oh hell, my 4 year old Android phone is a more powerful computer than
the mainframe (an IBM1620) that my college had. Though the
blinkenlights are much inferior.

Went up to Essex Uni in 1969 and their mainframe was in the ICL1900
series.
When I left in 1972 it was a PDP10.
I wonder what they have now, nearly 50 years on?

Probably don’t have a mainframe, but if they did it wouldn’t be as nice
a machine as the PDP-10.

I used that machine 1973-74! I was 2600,2645.

[Mike Spencer]

Post by maus
The Chaos group in Germany had members interested in such things,
from illuminating the windows of large buildings to form text
messages, down to what you mention. Their meetings are in Leipzig
this year.

Recall the final scene in "Hackers" and the "Crash & Burn" building?

[Questor]

Post by gareth evans
For Xmyth this year, I have 4 strings of multi-coloured LEDs
spread out over the front garden, with a total of about 1000 LEDs
for a total outlay of about £100.
Stack overflow possibly? After one of the strings of LEDs has cycled
through its repertoire a number of times, they all extinguish and
stay dark, but if I cycle the power, they all return, so it isn't
an overheating problem.

Pop open the controller, suck out the embedded code, and debug it.
Get back to us with what you find.

[Ahem A Rivet's Shot]

On Tue, 08 Dec 2020 18:08:56 GMT

Post by Questor

Post by gareth evans
For Xmyth this year, I have 4 strings of multi-coloured LEDs
spread out over the front garden, with a total of about 1000 LEDs
for a total outlay of about £100.
Stack overflow possibly? After one of the strings of LEDs has cycled
through its repertoire a number of times, they all extinguish and
stay dark, but if I cycle the power, they all return, so it isn't
an overheating problem.

Pop open the controller,

Replace with a RPi Zero running a PDP-11 emulator (this is a.f.c!)
and write your own.

[gareth evans]

Post by Ahem A Rivet's Shot
On Tue, 08 Dec 2020 18:08:56 GMT

Post by Questor

Post by gareth evans
For Xmyth this year, I have 4 strings of multi-coloured LEDs
spread out over the front garden, with a total of about 1000 LEDs
for a total outlay of about £100.
Stack overflow possibly? After one of the strings of LEDs has cycled
through its repertoire a number of times, they all extinguish and
stay dark, but if I cycle the power, they all return, so it isn't
an overheating problem.

Pop open the controller,

Replace with a RPi Zero running a PDP-11 emulator (this is a.f.c!)
and write your own.

It raises a question about the integration inside the LEDs themselves,
because only two wires come out of the controller / wall wart and yet
the string sequencing drives the LEDs into two distinct groups.

[Ahem A Rivet's Shot]

On Tue, 8 Dec 2020 21:01:07 +0000

Post by gareth evans

Post by Ahem A Rivet's Shot
On Tue, 08 Dec 2020 18:08:56 GMT

On Mon, 7 Dec 2020 11:38:30 +0000, gareth evans

Post by gareth evans
For Xmyth this year, I have 4 strings of multi-coloured LEDs
spread out over the front garden, with a total of about 1000 LEDs
for a total outlay of about £100.
Stack overflow possibly? After one of the strings of LEDs has cycled
through its repertoire a number of times, they all extinguish and
stay dark, but if I cycle the power, they all return, so it isn't
an overheating problem.

Pop open the controller,

Replace with a RPi Zero running a PDP-11 emulator (this is
a.f.c!) and write your own.

It raises a question about the integration inside the LEDs themselves,
because only two wires come out of the controller / wall wart and yet
the string sequencing drives the LEDs into two distinct groups.

The D in LED may be significant here, perhaps half of them are one
way round and half the other with the supply reversing polarity[1] to switch
sets.

[1] of the electron flow.

[Charlie Gibbs]

Post by Ahem A Rivet's Shot
On Tue, 8 Dec 2020 21:01:07 +0000

Post by gareth evans
It raises a question about the integration inside the LEDs themselves,
because only two wires come out of the controller / wall wart and yet
the string sequencing drives the LEDs into two distinct groups.

The D in LED may be significant here, perhaps half of them are one
way round and half the other with the supply reversing polarity[1] to switch
sets.
[1] of the electron flow.

That was my first thought. That reminds me of an article I once read by
a railroad modeler who found a unit that combined red and green LEDs in
a single package. He used it to create a track signal. Apply DC one way
and it lit up red, apply DC the other way and it lit up green - and apply
AC and it lit up yellow. Cute.

[gareth evans]

Post by Charlie Gibbs

Post by Ahem A Rivet's Shot
On Tue, 8 Dec 2020 21:01:07 +0000

Post by gareth evans
It raises a question about the integration inside the LEDs themselves,
because only two wires come out of the controller / wall wart and yet
the string sequencing drives the LEDs into two distinct groups.

The D in LED may be significant here, perhaps half of them are one
way round and half the other with the supply reversing polarity[1] to switch
sets.
[1] of the electron flow.

That was my first thought. That reminds me of an article I once read by
a railroad modeler who found a unit that combined red and green LEDs in
a single package. He used it to create a track signal. Apply DC one way
and it lit up red, apply DC the other way and it lit up green - and apply
AC and it lit up yellow. Cute.

Reminds me of the time (40+ years ago) working on automation in
coal mines. (The MINOS system from MRDE at Bretby).

Any remote alarm signal resulted in an open contact, with the
safe postiion being normally closed but in series with a diode,
with the excitation being AC.

This resulted in three distinct signals ...

No signal; either the alarm or the line has been cut.

Halfrectified DC; No alarm.

Full AC; the line has been short circuited somewhere.

This arrangement was known as Line Proving.

[Dennis Boone]

Post by gareth evans
It raises a question about the integration inside the LEDs themselves,
because only two wires come out of the controller / wall wart and yet
the string sequencing drives the LEDs into two distinct groups.

Many of these strings of LEDs use a shift-in / shift-out model where you
clock out settings for each LED in turn. The LEDs are in series on the
line, and when new data arrives, they shift the previous data on down
the line, and at the end of sending enough for each LED, the first
setting out has reached the end of the string.

De