Questions tagged [electronics]
Electrical-engineering aspects of retrocomputing: circuit design, hardware interfaces, electronic signalling.
5 questions
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Why is one of the Intel 8042 keyboard controller outputs inverted?
The IBM PC/AT includes an Intel 8042 microcontroller mask-programmed to act as a keyboard controller. From the processor, it is accessible through two ports at addresses 60h and 64h, and it ...
12
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Do IDE data lines need pull-up resistors?
This is somewhat of a long story but I think it's needed for background. I'll try to keep it short.
I obtained a number of these 44 pin SSD modules.
They are not 2.5" format, but have the same ...
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33
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What is the Commodore 64C "France version" and why does it need a beefy resistor?
While perusing the schematics for the Commodore 64C (titled COMMODORE-64 B/NE) I came across a suspicious section of the power supply: The unregulated "9V" is connected to the completely ...
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Z80, do I need a resistor for pins to Vcc?
Building a Z80 computer after completing one with 65C02.
Z80 on my project needs some pins to be tied high (INT, NMI, WAIT, BUSRQ), these are the ones that I don't need for the time being. There are ...
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Did any Apple II games use a "timing resistor"?
A science-lab program for the Apple II (I forget the name) had a board that plugged into the joystick port and included a "timing resistor". While I don't know what the program actually did with the ...
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