Why could you hear an Amstrad CPC working? The 2019 Stack Overflow Developer Survey Results...
What is the use of option -o in the useradd command?
"What time...?" or "At what time...?" - what is more grammatically correct?
JSON.serialize: is it possible to suppress null values of a map?
If Wish Duplicates Simulacrum, Are Existing Duplicates Destroyed?
Unbreakable Formation vs. Cry of the Carnarium
"To split hairs" vs "To be pedantic"
Why can Shazam do this?
A poker game description that does not feel gimmicky
How are circuits which use complex ICs normally simulated?
What is the steepest angle that a canal can be traversable without locks?
What could be the right powersource for 15 seconds lifespan disposable giant chainsaw?
Poison Arrows Piercing damage reduced to 0, do you still get poisoned?
Does light intensity oscillate really fast since it is a wave?
Should I write numbers in words or as symbols in this case?
What are the motivations for publishing new editions of an existing textbook, beyond new discoveries in a field?
Pristine Bit Checking
Patience, young "Padovan"
Lethal sonic weapons
It's possible to achieve negative score?
How was Skylab's orbit inclination chosen?
Is flight data recorder erased after every flight?
I see my dog run
Where to refill my bottle in India?
Landlord wants to switch my lease to a "Land contract" to "get back at the city"
Why could you hear an Amstrad CPC working?
The 2019 Stack Overflow Developer Survey Results Are InIs it possible to use an Amstrad CPC464 with a modern monitor or TVMemory sharing mechanism in the Amstrad CPC computerWhy CPC464 display is less stable while reading from cassette?Amstrad CPC 464 tape deck loads, but makes grinding scratching noisecbm prg studio for the AmstradCommon practices of programming the AY-3-8910 on Amstrad CPC: via Firmware routines or directly?
I had my first programming experience in the late 80s / early 90s on a Schneider (Amstrad) CPC 464 in Basic.
I remember that when a program was running, depending on the current workload of the processor you could hear a faint buzzing sound from the integrated speakers.
Especially when an empty for loop was running (like for i = 1 to 500 : next) which was regularly used to get short waiting times (as there was no sleep command IIRC), you could hear this buzzing which gradually changed its frequency during the loop.
My question is: Was this a feature (as an audible feedback that the computer was working) or a consequence from insufficient decoupling of circuits?
cpc464
asked 7 hours ago
elzellelzell
1212
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I had my first programming experience in the late 80s / early 90s on a Schneider (Amstrad) CPC 464 in Basic.
I remember that when a program was running, depending on the current workload of the processor you could hear a faint buzzing sound from the integrated speakers.
Especially when an empty for loop was running (like for i = 1 to 500 : next) which was regularly used to get short waiting times (as there was no sleep command IIRC), you could hear this buzzing which gradually changed its frequency during the loop.
My question is: Was this a feature (as an audible feedback that the computer was working) or a consequence from insufficient decoupling of circuits?
cpc464
asked 7 hours ago
elzellelzell
1212
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
True story, I was writing some 3D graphics code on Sinclair PC200, and could hear the loop skipping triangles or processing them. That guided my optimization efforts for a more efficient hash.
– void_ptr
37 mins ago
add a comment |
I had my first programming experience in the late 80s / early 90s on a Schneider (Amstrad) CPC 464 in Basic.
I remember that when a program was running, depending on the current workload of the processor you could hear a faint buzzing sound from the integrated speakers.
Especially when an empty for loop was running (like for i = 1 to 500 : next) which was regularly used to get short waiting times (as there was no sleep command IIRC), you could hear this buzzing which gradually changed its frequency during the loop.
My question is: Was this a feature (as an audible feedback that the computer was working) or a consequence from insufficient decoupling of circuits?
cpc464
asked 7 hours ago
elzellelzell
1212
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I had my first programming experience in the late 80s / early 90s on a Schneider (Amstrad) CPC 464 in Basic.
I remember that when a program was running, depending on the current workload of the processor you could hear a faint buzzing sound from the integrated speakers.
Especially when an empty for loop was running (like for i = 1 to 500 : next) which was regularly used to get short waiting times (as there was no sleep command IIRC), you could hear this buzzing which gradually changed its frequency during the loop.
My question is: Was this a feature (as an audible feedback that the computer was working) or a consequence from insufficient decoupling of circuits?
cpc464
cpc464
asked 7 hours ago
elzellelzell
1212
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 7 hours ago
elzellelzell
1212
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 7 hours ago
elzellelzell
1212
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 7 hours ago
elzellelzell
1212
asked 7 hours ago
elzellelzell
1212
1212
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
elzell is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
True story, I was writing some 3D graphics code on Sinclair PC200, and could hear the loop skipping triangles or processing them. That guided my optimization efforts for a more efficient hash.
– void_ptr
37 mins ago
add a comment |
True story, I was writing some 3D graphics code on Sinclair PC200, and could hear the loop skipping triangles or processing them. That guided my optimization efforts for a more efficient hash.
– void_ptr
37 mins ago
True story, I was writing some 3D graphics code on Sinclair PC200, and could hear the loop skipping triangles or processing them. That guided my optimization efforts for a more efficient hash.
– void_ptr
37 mins ago
True story, I was writing some 3D graphics code on Sinclair PC200, and could hear the loop skipping triangles or processing them. That guided my optimization efforts for a more efficient hash.
– void_ptr
37 mins ago
add a comment |
1 Answer
1
active
oldest
votes
There seems to be a slight misunderstanding: The CPU in a computer is (almost) never doing nothing (excluding power save states which was largely unknown at times the Amstrad was en vogue). So there's no such thing as "workload of a processor" going up or down - The CPU in an Amstrad is constantly running at 4 MHz, constantly under the same workload. If there's nothing do do, like executing a BASIC program), the CPU is, well, busy idling around at the same speed with the same "workload".
What you possibly can hear, however, is the CPU repeatedly doing the same thing, like operating in tight loops that can, through electrical or mechanical interference (with the monitor or audio signal, for example), create audible frequencies that you may hear. That was definitely not an intended feature.
Operators of mainframes sometimes could hear whether their machines were running properly (or had crashed) by listening to the interference noise they produced, sometimes even tried to amplify the noise. (See this book, page 161ff)
You were experiencing some similar effect.
Today, the sound of historic computers operating can even be marketed as art.
answered 5 hours ago
tofrotofro
16.6k33493
2
...or, by placing a cheap AM radio near the CPU. I knew a guy in college who programmed his Altair 8800 to play recognizable tunes through a nearby AM radio. Computers back in the day did not exactly comply with FCC regulations.
– Solomon Slow
3 hours ago
"Workload" certainly is meaningful, even in the days of the Amstrad. If you're just executing a sequence ofnops, that means a whole lot of CPU circuits are sitting there idle, not drawing significant power. (An empty loop in BASIC is very much not a case of the CPU being idle, though.)
– Mark
1 hour ago
Even if that is not a "normal" use case, I pretty much doubt a Z80 on NOPs draws significantly less current than when executing any other instruction. Have you got proof of that? Pretty much the only circuit not required for NOPs is the ALU - And my guess would be that is not responsible for the most significant power consumption. A Z80 in HALT state might have a measurable difference in current draw, but most probably NOPs will not lower that.
– tofro
1 hour ago
add a comment |
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "648"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
elzell is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fretrocomputing.stackexchange.com%2fquestions%2f9634%2fwhy-could-you-hear-an-amstrad-cpc-working%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
There seems to be a slight misunderstanding: The CPU in a computer is (almost) never doing nothing (excluding power save states which was largely unknown at times the Amstrad was en vogue). So there's no such thing as "workload of a processor" going up or down - The CPU in an Amstrad is constantly running at 4 MHz, constantly under the same workload. If there's nothing do do, like executing a BASIC program), the CPU is, well, busy idling around at the same speed with the same "workload".
What you possibly can hear, however, is the CPU repeatedly doing the same thing, like operating in tight loops that can, through electrical or mechanical interference (with the monitor or audio signal, for example), create audible frequencies that you may hear. That was definitely not an intended feature.
Operators of mainframes sometimes could hear whether their machines were running properly (or had crashed) by listening to the interference noise they produced, sometimes even tried to amplify the noise. (See this book, page 161ff)
You were experiencing some similar effect.
Today, the sound of historic computers operating can even be marketed as art.
answered 5 hours ago
tofrotofro
16.6k33493
2
...or, by placing a cheap AM radio near the CPU. I knew a guy in college who programmed his Altair 8800 to play recognizable tunes through a nearby AM radio. Computers back in the day did not exactly comply with FCC regulations.
– Solomon Slow
3 hours ago
"Workload" certainly is meaningful, even in the days of the Amstrad. If you're just executing a sequence ofnops, that means a whole lot of CPU circuits are sitting there idle, not drawing significant power. (An empty loop in BASIC is very much not a case of the CPU being idle, though.)
– Mark
1 hour ago
Even if that is not a "normal" use case, I pretty much doubt a Z80 on NOPs draws significantly less current than when executing any other instruction. Have you got proof of that? Pretty much the only circuit not required for NOPs is the ALU - And my guess would be that is not responsible for the most significant power consumption. A Z80 in HALT state might have a measurable difference in current draw, but most probably NOPs will not lower that.
– tofro
1 hour ago
add a comment |
There seems to be a slight misunderstanding: The CPU in a computer is (almost) never doing nothing (excluding power save states which was largely unknown at times the Amstrad was en vogue). So there's no such thing as "workload of a processor" going up or down - The CPU in an Amstrad is constantly running at 4 MHz, constantly under the same workload. If there's nothing do do, like executing a BASIC program), the CPU is, well, busy idling around at the same speed with the same "workload".
What you possibly can hear, however, is the CPU repeatedly doing the same thing, like operating in tight loops that can, through electrical or mechanical interference (with the monitor or audio signal, for example), create audible frequencies that you may hear. That was definitely not an intended feature.
Operators of mainframes sometimes could hear whether their machines were running properly (or had crashed) by listening to the interference noise they produced, sometimes even tried to amplify the noise. (See this book, page 161ff)
You were experiencing some similar effect.
Today, the sound of historic computers operating can even be marketed as art.
answered 5 hours ago
tofrotofro
16.6k33493
2
...or, by placing a cheap AM radio near the CPU. I knew a guy in college who programmed his Altair 8800 to play recognizable tunes through a nearby AM radio. Computers back in the day did not exactly comply with FCC regulations.
– Solomon Slow
3 hours ago
"Workload" certainly is meaningful, even in the days of the Amstrad. If you're just executing a sequence ofnops, that means a whole lot of CPU circuits are sitting there idle, not drawing significant power. (An empty loop in BASIC is very much not a case of the CPU being idle, though.)
– Mark
1 hour ago
Even if that is not a "normal" use case, I pretty much doubt a Z80 on NOPs draws significantly less current than when executing any other instruction. Have you got proof of that? Pretty much the only circuit not required for NOPs is the ALU - And my guess would be that is not responsible for the most significant power consumption. A Z80 in HALT state might have a measurable difference in current draw, but most probably NOPs will not lower that.
– tofro
1 hour ago
add a comment |
There seems to be a slight misunderstanding: The CPU in a computer is (almost) never doing nothing (excluding power save states which was largely unknown at times the Amstrad was en vogue). So there's no such thing as "workload of a processor" going up or down - The CPU in an Amstrad is constantly running at 4 MHz, constantly under the same workload. If there's nothing do do, like executing a BASIC program), the CPU is, well, busy idling around at the same speed with the same "workload".
What you possibly can hear, however, is the CPU repeatedly doing the same thing, like operating in tight loops that can, through electrical or mechanical interference (with the monitor or audio signal, for example), create audible frequencies that you may hear. That was definitely not an intended feature.
Operators of mainframes sometimes could hear whether their machines were running properly (or had crashed) by listening to the interference noise they produced, sometimes even tried to amplify the noise. (See this book, page 161ff)
You were experiencing some similar effect.
Today, the sound of historic computers operating can even be marketed as art.
answered 5 hours ago
tofrotofro
16.6k33493
There seems to be a slight misunderstanding: The CPU in a computer is (almost) never doing nothing (excluding power save states which was largely unknown at times the Amstrad was en vogue). So there's no such thing as "workload of a processor" going up or down - The CPU in an Amstrad is constantly running at 4 MHz, constantly under the same workload. If there's nothing do do, like executing a BASIC program), the CPU is, well, busy idling around at the same speed with the same "workload".
What you possibly can hear, however, is the CPU repeatedly doing the same thing, like operating in tight loops that can, through electrical or mechanical interference (with the monitor or audio signal, for example), create audible frequencies that you may hear. That was definitely not an intended feature.
Operators of mainframes sometimes could hear whether their machines were running properly (or had crashed) by listening to the interference noise they produced, sometimes even tried to amplify the noise. (See this book, page 161ff)
You were experiencing some similar effect.
Today, the sound of historic computers operating can even be marketed as art.
answered 5 hours ago
tofrotofro
16.6k33493
edited 5 hours ago
answered 5 hours ago
tofrotofro
16.6k33493
answered 5 hours ago
tofrotofro
16.6k33493
answered 5 hours ago
tofrotofro
16.6k33493
16.6k33493
2
...or, by placing a cheap AM radio near the CPU. I knew a guy in college who programmed his Altair 8800 to play recognizable tunes through a nearby AM radio. Computers back in the day did not exactly comply with FCC regulations.
– Solomon Slow
3 hours ago
"Workload" certainly is meaningful, even in the days of the Amstrad. If you're just executing a sequence ofnops, that means a whole lot of CPU circuits are sitting there idle, not drawing significant power. (An empty loop in BASIC is very much not a case of the CPU being idle, though.)
– Mark
1 hour ago
Even if that is not a "normal" use case, I pretty much doubt a Z80 on NOPs draws significantly less current than when executing any other instruction. Have you got proof of that? Pretty much the only circuit not required for NOPs is the ALU - And my guess would be that is not responsible for the most significant power consumption. A Z80 in HALT state might have a measurable difference in current draw, but most probably NOPs will not lower that.
– tofro
1 hour ago
add a comment |
2
...or, by placing a cheap AM radio near the CPU. I knew a guy in college who programmed his Altair 8800 to play recognizable tunes through a nearby AM radio. Computers back in the day did not exactly comply with FCC regulations.
– Solomon Slow
3 hours ago
"Workload" certainly is meaningful, even in the days of the Amstrad. If you're just executing a sequence ofnops, that means a whole lot of CPU circuits are sitting there idle, not drawing significant power. (An empty loop in BASIC is very much not a case of the CPU being idle, though.)
– Mark
1 hour ago
Even if that is not a "normal" use case, I pretty much doubt a Z80 on NOPs draws significantly less current than when executing any other instruction. Have you got proof of that? Pretty much the only circuit not required for NOPs is the ALU - And my guess would be that is not responsible for the most significant power consumption. A Z80 in HALT state might have a measurable difference in current draw, but most probably NOPs will not lower that.
– tofro
1 hour ago
2
2
...or, by placing a cheap AM radio near the CPU. I knew a guy in college who programmed his Altair 8800 to play recognizable tunes through a nearby AM radio. Computers back in the day did not exactly comply with FCC regulations.
– Solomon Slow
3 hours ago
...or, by placing a cheap AM radio near the CPU. I knew a guy in college who programmed his Altair 8800 to play recognizable tunes through a nearby AM radio. Computers back in the day did not exactly comply with FCC regulations.
– Solomon Slow
3 hours ago
"Workload" certainly is meaningful, even in the days of the Amstrad. If you're just executing a sequence of
nops, that means a whole lot of CPU circuits are sitting there idle, not drawing significant power. (An empty loop in BASIC is very much not a case of the CPU being idle, though.)– Mark
1 hour ago
"Workload" certainly is meaningful, even in the days of the Amstrad. If you're just executing a sequence of
nops, that means a whole lot of CPU circuits are sitting there idle, not drawing significant power. (An empty loop in BASIC is very much not a case of the CPU being idle, though.)– Mark
1 hour ago
Even if that is not a "normal" use case, I pretty much doubt a Z80 on NOPs draws significantly less current than when executing any other instruction. Have you got proof of that? Pretty much the only circuit not required for NOPs is the ALU - And my guess would be that is not responsible for the most significant power consumption. A Z80 in HALT state might have a measurable difference in current draw, but most probably NOPs will not lower that.
– tofro
1 hour ago
Even if that is not a "normal" use case, I pretty much doubt a Z80 on NOPs draws significantly less current than when executing any other instruction. Have you got proof of that? Pretty much the only circuit not required for NOPs is the ALU - And my guess would be that is not responsible for the most significant power consumption. A Z80 in HALT state might have a measurable difference in current draw, but most probably NOPs will not lower that.
– tofro
1 hour ago
add a comment |
elzell is a new contributor. Be nice, and check out our Code of Conduct.
elzell is a new contributor. Be nice, and check out our Code of Conduct.
elzell is a new contributor. Be nice, and check out our Code of Conduct.
elzell is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Retrocomputing Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fretrocomputing.stackexchange.com%2fquestions%2f9634%2fwhy-could-you-hear-an-amstrad-cpc-working%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
True story, I was writing some 3D graphics code on Sinclair PC200, and could hear the loop skipping triangles or processing them. That guided my optimization efforts for a more efficient hash.
– void_ptr
37 mins ago