SOLVED ntsc sinclar ql schematics ??
SOLVED ntsc sinclar ql schematics ??
Is there any information available about the usa / ntsc version of the ql ??
does a service manual excist ?
does a service manual excist ?
Last edited by techy on Tue Apr 23, 2024 12:50 pm, edited 1 time in total.
Zx80-1/3k exp.-zx81-16k exp.- Spectrum 48 - Spectrum+ -Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo - Velleman interface system - Currah microspeech - Ql - Miracle 512k exp.- Ql printer - Cst Qdisk interf.- Qubide - Double 3.5 floppy- Minerva - Ice 1.9 - Ql Usb mouse adapter - Qimi-and much more .
Re: ntsc sinclar ql schematics ??
The only changes to the US QL from the German QL are:
- US modulator/filters/xtal and modest component value changes around MC1377.
- A bodge board glued on the RAM from the clock crystal that passes the clock through two inverting gates to buffer and clean it up a bit. This gets the clock much closer to a 50/50 duty cycle.
- The OS sets a bit in the 8301 to NTSC. This is the only difference in JSU from JS. Only one ROM IC is affected so the other ROM will likely just say JS. The character set, default Mode 2 resolutions and window positions are different.
- The incoming 9VAC nominal line is wrapped through a large circular ferrite ring to reduce noise.
- On some units, extra tantalum bead capacitors are laid diagonally from Vdd to Vss to decrease ground bounce.
- The interior of the enclosure is metalized and contains grounding strips to force good electrical contact between the shell halves.
Re: ntsc sinclar ql schematics ??
A little off topic, but what was the US QL keyboard layout? Was it close to UK?
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Re: ntsc sinclar ql schematics ??
Hi Peter
To be fair, the UK keyboard was already pretty much based on the US layout - something I was surprised to discover when developing the extra language maps for the Qbase
To be fair, the UK keyboard was already pretty much based on the US layout - something I was surprised to discover when developing the extra language maps for the Qbase
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Re: ntsc sinclar ql schematics ??
Hi,
I was updating the QL Service Manual, which details only Issue 5, 6 UK boards.
Is the USA and German QL circuit board require to be detailed.
The problem, I do not have either these QL boards, so it would be guesswork.
I was updating the QL Service Manual, which details only Issue 5, 6 UK boards.
Is the USA and German QL circuit board require to be detailed.
The problem, I do not have either these QL boards, so it would be guesswork.
Last edited by Derek_Stewart on Mon Apr 22, 2024 7:07 pm, edited 1 time in total.
Regards,
Derek
Derek
Re: ntsc sinclar ql schematics ??
Thanks for this info ( kept me searching for some time )
regarding the rgb output , will that still be the same as our uk versions ?
regarding the rgb output , will that still be the same as our uk versions ?
Zx80-1/3k exp.-zx81-16k exp.- Spectrum 48 - Spectrum+ -Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo - Velleman interface system - Currah microspeech - Ql - Miracle 512k exp.- Ql printer - Cst Qdisk interf.- Qubide - Double 3.5 floppy- Minerva - Ice 1.9 - Ql Usb mouse adapter - Qimi-and much more .
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- Font of All Knowledge
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- Joined: Mon Dec 20, 2010 11:40 am
- Location: Sunny Runcorn, Cheshire, UK
Re: ntsc sinclar ql schematics ??
Hi,Dave wrote: ↑Sun Apr 21, 2024 6:40 pm The only changes to the US QL from the German QL are:
- US modulator/filters/xtal and modest component value changes around MC1377.
- A bodge board glued on the RAM from the clock crystal that passes the clock through two inverting gates to buffer and clean it up a bit. This gets the clock much closer to a 50/50 duty cycle.
- The OS sets a bit in the 8301 to NTSC. This is the only difference in JSU from JS. Only one ROM IC is affected so the other ROM will likely just say JS. The character set, default Mode 2 resolutions and window positions are different.
- The incoming 9VAC nominal line is wrapped through a large circular ferrite ring to reduce noise.
- On some units, extra tantalum bead capacitors are laid diagonally from Vdd to Vss to decrease ground bounce.
- The interior of the enclosure is metalized and contains grounding strips to force good electrical contact between the shell halves.
I have added this detail to the QL Service Manual update.
Last edited by Derek_Stewart on Tue Apr 23, 2024 11:04 pm, edited 1 time in total.
Regards,
Derek
Derek
Re: ntsc sinclar ql schematics ??
The RGB is, yes. The one small difference is that the US QL's (as well as some other regions) don't seem to give a color composite signal on pin 1. Instead, it just outputs 5 volts. You can grab the composite off of the MC1377. The monochrome composite is, however available on pin 3.
Re: ntsc sinclar ql schematics ??
Thanks to all ,
this has given me a clear insight in the differences between the versions .
And would also benefit others to know them .
this has given me a clear insight in the differences between the versions .
And would also benefit others to know them .
Zx80-1/3k exp.-zx81-16k exp.- Spectrum 48 - Spectrum+ -Spectrum 128- Interface 1 - DIVide - Zx flashcard- Zx printer - Ram turbo - Velleman interface system - Currah microspeech - Ql - Miracle 512k exp.- Ql printer - Cst Qdisk interf.- Qubide - Double 3.5 floppy- Minerva - Ice 1.9 - Ql Usb mouse adapter - Qimi-and much more .