and just in case I
always keep a description of them on every Pi
Maybe I just write my own OS and be done with it
wrote a multitasker for Z80 long time ago
Few lines, world has bloated after that.
On Sun, 30 Oct 2022 06:01:00 GMT
Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
Maybe I just write my own OS and be done with it
wrote a multitasker for Z80 long time ago
Few lines, world has bloated after that.
Be careful!
Linux started because Linus Torvalds had a neat idea for task
switching on a 386 - just a few lines of code that grew into a kernel and
met GNU looking for a kernel.
wrote my own CP/M clone:
http://panteltje.com/panteltje/z80/index.html
The OS:
http://panteltje.com/panteltje/z80/system14/index.html
The hardware (designed it too):
http://panteltje.com/panteltje/z80/system14/diagrams/index.html
On Sun, 30 Oct 2022 08:00:05 GMT
Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
wrote my own CP/M clone:
http://panteltje.com/panteltje/z80/index.html
The OS:
http://panteltje.com/panteltje/z80/system14/index.html
The hardware (designed it too):
http://panteltje.com/panteltje/z80/system14/diagrams/index.html
I managed to get paid for doing both of those things in 1982, my
first job out of college.
If a WW3 nuke war happens and a big EMP destroys all smartphones, then knowing how to send an SOS with the simplest means ... (I am a radio ham
too) other than with smoke signals... bit of knowhow may help.
On Sun, 30 Oct 2022 12:33:29 GMT
Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
If a WW3 nuke war happens and a big EMP destroys all smartphones, then
knowing how to send an SOS with the simplest means ... (I am a radio ham
too) other than with smoke signals... bit of knowhow may help.
I'm pretty sure I could manage a spark gap transmitter with nothing
electronic available (my morse is *very* rusty though) - for a crystal >receiver I'd need a good high impedance earpiece which would be trickier.
On a sunny day (Sun, 30 Oct 2022 13:23:15 +0000) it happened Ahem A
Rivet's Shot <steveo@eircom.net> wrote in <20221030132315.9aeeb170174a5222d19a01bc@eircom.net>:
On Sun, 30 Oct 2022 12:33:29 GMT Jan Panteltje
<pNaonStpealmtje@yahoo.com> wrote:
If a WW3 nuke war happens and a big EMP destroys all smartphones, then
knowing how to send an SOS with the simplest means ... (I am a radio
ham too) other than with smoke signals... bit of knowhow may help.
I had one of those crystal earphones once in the late fifties or early sixties. crystal radios, tune with a ferrite rod shifting in the coil
seen those on ebay,
Spark transmitter I have tried, worked, used an old car ignition coil
:-) local radio ham got very upset..
Useful, thanks. But yeah, I do always go with a completely new image on RasPis. I sorta know my customisations by heart now, and just in case I always keep a description of them on every Pi. So I spend that half hour waiting time doing that. An alternative would be automation with e.g. Ansible, but meh.
On Sun, 30 Oct 2022 16:23:15 GMT, Jan Panteltje wrote:
I had one of those crystal earphones once in the late fifties or early
sixties. crystal radios, tune with a ferrite rod shifting in the coil
I built a broadcast AM crystal set when I was about 11 - hand-wound coil
on a cardboard tube former, but mine had a multi-blage rotary capacitor
for tuning and a glass-encapsulated germanium diode.
On Sun, 30 Oct 2022 16:23:15 GMT, Jan Panteltje wrote:
On a sunny day (Sun, 30 Oct 2022 13:23:15 +0000) it happened Ahem A
Rivet's Shot <steveo@eircom.net> wrote in
<20221030132315.9aeeb170174a5222d19a01bc@eircom.net>:
On Sun, 30 Oct 2022 12:33:29 GMT Jan Panteltje >>><pNaonStpealmtje@yahoo.com> wrote:
If a WW3 nuke war happens and a big EMP destroys all smartphones, then >>>> knowing how to send an SOS with the simplest means ... (I am a radio
ham too) other than with smoke signals... bit of knowhow may help.
From what I've read the EMP would take out rather more than smartphones.
I had one of those crystal earphones once in the late fifties or earlyI built a broadcast AM crystal set when I was about 11 - hand-wound coil
sixties. crystal radios, tune with a ferrite rod shifting in the coil
on a cardboard tube former, but mine had a multi-blage rotary capacitor
for tuning and a glass-encapsulated germanium diode.
I forget where the earphones came from but they were certainly high >impedance. IIRC the sound quality was surprisingly good and, of course, no >battery needed. This was a year or two before portable transistor radios >first appeared -and before individually packaged unijunction germanium >transistors appeared (think OC-72 single junction devices in metal of
glass packaging).
No suitable headphones? Easily replaced by an 80mm speaker plus a small
amp (LM358 + 470m pot + 4.7M feedback resistor or some equivalent IC amp)
and a battery or small solar panel for power.
seen those on ebay,Never tried that, but did enjoy playing with WS48 sets while at secondary >school: mt school had a compulsory cadet corps but joining the Signals >Platoon got some of us out of a lot of square bashing.
Spark transmitter I have tried, worked, used an old car ignition coil
:-) local radio ham got very upset..
The WS48 was a battery-operated WW2 infantry backpack radio:
http://www.radiomilitari.com/ws48.html
FWIW, and to get back (partly) on topic for this 'ere newsgroup the first >computer I saw (and programmed) was an Elliott 503 scientific computer.
8 track paper tape input, 8 track tape or fast 132 column drum printer >output. It was about 4 wardrobe-size grey cabinets plus a control console. >Its logic built using discrete transistors. It had ferrite core memory (39 >bit words) and packed two instructions per word. It was programmed in
Algol 60. Special feature: it implemented hardware floating point
arithmetic which was slightly faster then its integer operations.
Yes, especially high altitude nukes would take out satellites I have
read the 'telstar' satellite was killed by a US high altitude nuke test,
But lots of other thing will go, cellphone towers, airplane electronics (helis could crash), what not.
But .. my first computer was a Sinclair ZX80 Then I bought the book "Microprocessor interfacing techniques' by Rodnay Zaks and things took
of from there interfacing that ZX80...
https://www.amazon.com/Microprocessor-Interfacing-Techniques-Rodnay- Zaks/dp/0895880296
On Mon, 31 Oct 2022 05:37:22 GMT, Jan Panteltje wrote:
Yes, especially high altitude nukes would take out satellites I haveSeems that, according to Wikipedia anyway, it took two high altitude nukes >(one US, one Soviet) plus a burst of solar radiation to kill Telstar 1.
read the 'telstar' satellite was killed by a US high altitude nuke test,
But lots of other thing will go, cellphone towers, airplane electronics
(helis could crash), what not.
But .. my first computer was a Sinclair ZX80 Then I bought the bookAfter the Elliott and graduation I joined ICL and learnt first 1900
"Microprocessor interfacing techniques' by Rodnay Zaks and things took
of from there interfacing that ZX80...
https://www.amazon.com/Microprocessor-Interfacing-Techniques-Rodnay-
Zaks/dp/0895880296
assembler and then COBOL, followed by various OSen up to and including >George3, multi-user, multitasking OS with a hierarchical directory
structure on a 32K 1903 (24 bit words) in 1970.
My first personal system was 6809-based (32KB RAM, 2 x 5.25" disks, 16 x
64 memory mapped display, on an SS-50 bus, with the FLEX-09 'OS'. I
bought the whole thing as a kit, soldered chips onto boards and debugged
it with a logic probe and multimeter. Since by then (1979) I was using 80
x 24 green screens at work I soon swapped the display board for a 24 x 80
one (also self-assembled and using a 2K EPROM as character generator.) >Rewrote the boot EPROM to suit.
Yes, after the ZX80 I bought a ZX81
Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
On a sunny day (Sun, 30 Oct 2022 13:23:15 +0000) it happened Ahem A Rivet's >> Shot <steveo@eircom.net> wrote in
<20221030132315.9aeeb170174a5222d19a01bc@eircom.net>:
On Sun, 30 Oct 2022 12:33:29 GMT
Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote:
If a WW3 nuke war happens and a big EMP destroys all smartphones, then >>>> knowing how to send an SOS with the simplest means ... (I am a radio ham >>>> too) other than with smoke signals... bit of knowhow may help.
I'm pretty sure I could manage a spark gap transmitter with nothing >>>electronic available (my morse is *very* rusty though) - for a crystal >>>receiver I'd need a good high impedance earpiece which would be trickier.
I had one of those crystal earphones once in the late fifties or early sixties,
seen those on ebay,
Spark transmitter I have tried, worked, used an old car ignition coil :-)
local radio ham got very upset..
I had one of those Radio Shack 150-project electronics kits back in the day. >One of the projects within was a spark-gap transmitter, in which a relay was >wired up with the normally-closed contacts set to cut power to the coil when >energized. I don't know how long it would've lasted before the relay >contacts were shot, but it succeeded at making detectable noise over most of >the AM band (though not to the extent that it interfered with broadcasters).
On a sunny day (Mon, 31 Oct 2022 17:20:27 GMT) it happened
I had one of those Radio Shack 150-project electronics kits back in the day. >> One of the projects within was a spark-gap transmitter, in which a relay was >> wired up with the normally-closed contacts set to cut power to the coil when >> energized. I don't know how long it would've lasted before the relay
contacts were shot, but it succeeded at making detectable noise over most of >> the AM band (though not to the extent that it interfered with broadcasters).
Ha, these days most wallwarts wil do that!
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