Its reference is R26 and its value is 2k2... It pulls down to ground the line between ULA and 74LS365 / Prom 256x4....
Is it an help / a need for generating the Red color ? Why is there nothing like that with the Green and the Blue colors ?
Or is it only used with the PROM ?
I don't understand why there is such a single resistor just there...
Does anybody have information about it ?
Thanks for teaching me !
What is the purpose of this resistor ?
What is the purpose of this resistor ?
Oric Atmos : a new life !
- mikeb
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Re: What is the purpose of this resistor ?
Secret purpose.
Gateway to Narnia.
Do not mess with it
It's been sat there looking out-of-place, and yet completely innocent, all these years, and its purpose is to stop that video "output" line accidentally floating up to +5v. Spoiler Alert: This pin is also an input, but its not documented, until I fell over it while doing this ...
http://oric.signal11.org.uk/files/pub/u ... Schems.pdf
The answers are in the above!
Gateway to Narnia.
Do not mess with it
It's been sat there looking out-of-place, and yet completely innocent, all these years, and its purpose is to stop that video "output" line accidentally floating up to +5v. Spoiler Alert: This pin is also an input, but its not documented, until I fell over it while doing this ...
http://oric.signal11.org.uk/files/pub/u ... Schems.pdf
The answers are in the above!
Re: What is the purpose of this resistor ?
Thank you Mikeb !
That is bright ! I couldn't imagine the concerned chip was the ULA !
A different design for the Red ! A pin with Output and Input :
19 OUT Video R
+ IN VC Reset 2
Now I can see why there is a "lost" resistor.
What a good job made with this document ! Congrats !
Merci encore !
That is bright ! I couldn't imagine the concerned chip was the ULA !
A different design for the Red ! A pin with Output and Input :
19 OUT Video R
+ IN VC Reset 2
Now I can see why there is a "lost" resistor.
What a good job made with this document ! Congrats !
Merci encore !
Oric Atmos : a new life !