Some of the discussion on this topic, suggests a lack of understanding of the differences between PAL and NTSC. A fundamental difference is: PAL uses 50Hz frame rates (vertical) and NTSC uses 60Hz. Why? It's AC power line frequency: the US uses 60Hz and the UK uses 50Hz. That has consequences. "Old" TV's in each country have analog circuits which produce vertical scan rates based on AC line frequency. The CRT video display, may see crawling horizontal "hum bars" from magnetically picking up AC line signals at one frequency while displaying another frequency. VCR's run motors and pull tapes, assuming one vertical frequency and not another. And some devices which claim PAL/NTSC compatibility, may more simply run PAL on 50Hz power and NTSC on 60Hz power. A video device that actually turns PAL signals and PAL frequencies, into NTSC signals and frequencies, would be a somewhat busy design. On the other hand, an LCD TV or monitor - which has no "hum bars" as it doesn't "scan" with a yoke coil, has little analog circuity, doesn't need to depend on the AC line for a frequency reference - can be set for PAL or NTSC and it's done. Also: if an old PAL computer is run from 60Hz AC power, it may use the AC line as a frequency source (to avoid those hum bars). It's then possible the "PAL" computer will try to produce 60Hz vertical video; but not necessarily PAL horizontal rates - depends on the design. I don't track these PAL/NTSC issues, or C-64's, but I'm aware of these consequences. That sets my expectations about fixing the problem - I don't expect "a cable" (wires only, not a dongle with a buried processor in it) to solve it. It will be interesting to read about the results on specific equipment. - Herb -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net
On Wed, Sep 19, 2018 at 9:51 AM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Some of the discussion on this topic, suggests a lack of understanding of the differences between PAL and NTSC. A fundamental difference is: PAL uses 50Hz frame rates (vertical) and NTSC uses 60Hz. Why? It's AC power line frequency: the US uses 60Hz and the UK uses 50Hz. That has consequences.
This is why I don't understand why people don't just match up a PAL-native machine with a PAL monitor and plug them both into a step down transformer. Botta boom. It's all about the Hz of the AC power. Change the Hz and you have a "PAL environment", no need to special converters, etc. Bill
A step down transformer only changes the voltage. It does not affect the frequency. You are still running at 60 Hz. Bill Dromgoole From: Bill Degnan via vcf-midatlantic Sent: Wednesday, September 19, 2018 2:52 PM To: vcf-midatlantic Cc: Bill Degnan Subject: Re: [vcf-midatlantic] PAL C-64 on 1084-S? On Wed, Sep 19, 2018 at 9:51 AM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Some of the discussion on this topic, suggests a lack of understanding of the differences between PAL and NTSC. A fundamental difference is: PAL uses 50Hz frame rates (vertical) and NTSC uses 60Hz. Why? It's AC power line frequency: the US uses 60Hz and the UK uses 50Hz. That has consequences.
This is why I don't understand why people don't just match up a PAL-native machine with a PAL monitor and plug them both into a step down transformer. Botta boom. It's all about the Hz of the AC power. Change the Hz and you have a "PAL environment", no need to special converters, etc. Bill
A transformer only changes the voltage, not the frequency. On Sep 19, 2018, at 2:51 PM, Bill Degnan via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote: On Wed, Sep 19, 2018 at 9:51 AM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Some of the discussion on this topic, suggests a lack of understanding of the differences between PAL and NTSC. A fundamental difference is: PAL uses 50Hz frame rates (vertical) and NTSC uses 60Hz. Why? It's AC power line frequency: the US uses 60Hz and the UK uses 50Hz. That has consequences.
This is why I don't understand why people don't just match up a PAL-native machine with a PAL monitor and plug them both into a step down transformer. Botta boom. It's all about the Hz of the AC power. Change the Hz and you have a "PAL environment", no need to special converters, etc. Bill
On Sep 19, 2018, at 2:51 PM, Bill Degnan via vcf-midatlantic <
vcf-midatlantic@lists.vcfed.org> wrote:
On Wed, Sep 19, 2018 at 9:51 AM Herb Johnson via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Some of the discussion on this topic, suggests a lack of understanding of the differences between PAL and NTSC. A fundamental difference is: PAL uses 50Hz frame rates (vertical) and NTSC uses 60Hz. Why? It's AC power line frequency: the US uses 60Hz and the UK uses 50Hz. That has consequences.
This is why I don't understand why people don't just match up a PAL-native machine with a PAL monitor and plug them both into a step down transformer. Botta boom. It's all about the Hz of the AC power. Change the Hz and you have a "PAL environment", no need to special converters, etc.
Bill
On Wed, Sep 19, 2018 at 3:32 PM <chrisjpf33@gmail.com> wrote:
A transformer only changes the voltage, not the frequency.
Really? Why wouldn't it do both? Do the nicer transformers also convert the Hz? This should not be a big issue? I have never done this though, who knows I suppose. b
On Wed, Sep 19, 2018 at 2:57 PM Bill Degnan via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Really? Why wouldn't it do both? Do the nicer transformers also convert the Hz? This should not be a big issue? I have never done this though, who knows I suppose. b
A transformer is fundamentally, two copper windings, magnetically coupled together. In a perfect world, the current/voltage relationship is kept between both sides, such that the power remains the same. Hence, if you have a 2:1 transformer, 240V on the first side would result in 120V on the second. If a load drawing 2A at 120V is placed on the second side, you can expect 1A to flow on the first. Hence, power is conserved. Note that there is no circuitry or magic here to change the frequency from one side to the other. If you have 60 Hz on the input, you'll get the same frequency on the output. Transformers often have frequency ratings, as the core can saturate and become less efficient when lower frequencies are supplied. Hence, a 60 Hz transformer may not operate well at 50 Hz, but a 50 Hz transformer will be able to handle both 50 Hz and 60 Hz. In order to do any sort of frequency conversion, an inverter is required, which often consists of electronics to synthesize a new frequency, but could also be some sort of motor-generator arrangement, especially for power applications. Kyle
On Wed, Sep 19, 2018 at 4:06 PM Kyle Owen via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
On Wed, Sep 19, 2018 at 2:57 PM Bill Degnan via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Really? Why wouldn't it do both? Do the nicer transformers also convert the Hz? This should not be a big issue? I have never done this though, who knows I suppose. b
<snip>
In order to do any sort of frequency conversion, an inverter is required, which often consists of electronics to synthesize a new frequency, but could also be some sort of motor-generator arrangement, especially for power applications.
Kyle
Thanks for the explanation. b
Very good explanation Kyle Mike R. Sent from: My extremely complicated, hand held electronic device.
On Sep 19, 2018, at 4:04 PM, Kyle Owen via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
On Wed, Sep 19, 2018 at 2:57 PM Bill Degnan via vcf-midatlantic < vcf-midatlantic@lists.vcfed.org> wrote:
Really? Why wouldn't it do both? Do the nicer transformers also convert the Hz? This should not be a big issue? I have never done this though, who knows I suppose. b
A transformer is fundamentally, two copper windings, magnetically coupled together. In a perfect world, the current/voltage relationship is kept between both sides, such that the power remains the same. Hence, if you have a 2:1 transformer, 240V on the first side would result in 120V on the second. If a load drawing 2A at 120V is placed on the second side, you can expect 1A to flow on the first. Hence, power is conserved.
Note that there is no circuitry or magic here to change the frequency from one side to the other. If you have 60 Hz on the input, you'll get the same frequency on the output.
Transformers often have frequency ratings, as the core can saturate and become less efficient when lower frequencies are supplied. Hence, a 60 Hz transformer may not operate well at 50 Hz, but a 50 Hz transformer will be able to handle both 50 Hz and 60 Hz.
In order to do any sort of frequency conversion, an inverter is required, which often consists of electronics to synthesize a new frequency, but could also be some sort of motor-generator arrangement, especially for power applications.
Kyle
This discussion is a really good example, of how we have to explain 20th century tech now, here in the 21st century. All the context of our (my) 20th C. analog world is becoming lost. Funny thing: AC line voltage is still 60Hz, and 50Hz in the UK. The last remnants of analog, struggle to survive in the digital age... I"ve been back-filling my Web site, to explain previously common tech, like: http://www.retrotechnology.com/restore/cass_data.html And of course of long-standing presence on my site: http://www.retrotechnology.com/herbs_stuff/drive.html I guess analog TV is next. So from my Flintstone's view: this is what preserving 20th Century vintage computing looks like. Herb Johnson paleodigital electrical engineer -- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT retrotechnology DOT info
What about a special exhibit on analogue technology.? NTSC and PAL CRT and LCD I even have a Sony Watchman still works! it would be great to get "George" running! Mike R. Sent from: My extremely complicated, hand held electronic device.
On Sep 19, 2018, at 5:35 PM, Herb Johnson via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> wrote:
This discussion is a really good example, of how we have to explain 20th century tech now, here in the 21st century. All the context of our (my) 20th C. analog world is becoming lost. Funny thing: AC line voltage is still 60Hz, and 50Hz in the UK. The last remnants of analog, struggle to survive in the digital age...
I"ve been back-filling my Web site, to explain previously common tech, like:
http://www.retrotechnology.com/restore/cass_data.html
And of course of long-standing presence on my site:
http://www.retrotechnology.com/herbs_stuff/drive.html
I guess analog TV is next.
So from my Flintstone's view: this is what preserving 20th Century vintage computing looks like.
Herb Johnson paleodigital electrical engineer
-- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net preserve, recover, restore 1970's computing email: hjohnson AT retrotechnology DOT com or try later herbjohnson AT retrotechnology DOT info
Certainly a good idea. Analog(ue) video technology as used by vintage computers. Some might say, it was "video" that was the "killer app" for personal computing. As in, computer gaming (Pong is an analog computer)? As in, TV Typewriter? As in, the first (?) video-out card for the S-100 by who - Cromemco? Processor Tech? Brilliant. Herb On 9/19/2018 6:57 PM, Sentrytv wrote:
What about a special exhibit on analogue technology.? NTSC and PAL CRT and LCD
I even have a Sony Watchman still works!
it would be great to get "George" running!
Mike R.
Sent from: My extremely complicated, hand held electronic device.
On Sep 19, 2018, at 5:35 PM, Herb Johnson wrote:
This discussion is a really good example, of how we have to explain 20th century tech now, here in the 21st century.
-- Herbert R. Johnson, New Jersey in the USA http://www.retrotechnology.com OR .net
it would be great to get "George" running!
It's on our (long) to-do list. Our top analog computing restorer is Bill I., who has his hands full with the EAI TR-20. That is a much smaller machine than George. When he finishes that, then we'll let him attack the big one. :)
Also keep in mind the TOD clock interrupt on (one of?) the CIA chips is clocked literally by the AC waveform, so if you have a 60hz AC input to a PAL c64, the TOD clock will run 20% too fast. On 9/19/2018 9:49 AM, Herb Johnson via vcf-midatlantic wrote:
Some of the discussion on this topic, suggests a lack of understanding of the differences between PAL and NTSC. A fundamental difference is: PAL uses 50Hz frame rates (vertical) and NTSC uses 60Hz. Why? It's AC power line frequency: the US uses 60Hz and the UK uses 50Hz. That has consequences.
"Old" TV's in each country have analog circuits which produce vertical scan rates based on AC line frequency. The CRT video display, may see crawling horizontal "hum bars" from magnetically picking up AC line signals at one frequency while displaying another frequency. VCR's run motors and pull tapes, assuming one vertical frequency and not another. And some devices which claim PAL/NTSC compatibility, may more simply run PAL on 50Hz power and NTSC on 60Hz power.
A video device that actually turns PAL signals and PAL frequencies, into NTSC signals and frequencies, would be a somewhat busy design. On the other hand, an LCD TV or monitor - which has no "hum bars" as it doesn't "scan" with a yoke coil, has little analog circuity, doesn't need to depend on the AC line for a frequency reference - can be set for PAL or NTSC and it's done.
Also: if an old PAL computer is run from 60Hz AC power, it may use the AC line as a frequency source (to avoid those hum bars). It's then possible the "PAL" computer will try to produce 60Hz vertical video; but not necessarily PAL horizontal rates - depends on the design.
I don't track these PAL/NTSC issues, or C-64's, but I'm aware of these consequences. That sets my expectations about fixing the problem - I don't expect "a cable" (wires only, not a dongle with a buried processor in it) to solve it. It will be interesting to read about the results on specific equipment. - Herb
-- Jonathan Gevaryahu jgevaryahu@gmail.com jgevaryahu@hotmail.com
participants (8)
-
Bill Degnan -
Bill Dromgoole -
chrisjpf33＠gmail.com -
Evan Koblentz -
Herb Johnson -
Jonathan Gevaryahu -
Kyle Owen -
Sentrytv