Unlike my floppy drive box, only a single goat has pissed on my PCjr box
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IBM mentions in passing in the technical reference that you could make other IR accessories for the system, but it was up to you to figure it out and the timings were tailored around the keyboard.
I'm not sure if anyone ever did - at least I'm not aware of any 3rd party IR accessories.
There's a fun video of LGR experiencing some ... issues with his PCjr IR port.
The beeping was an intentional feature by IBM to inform you that you had a bad keyboard signal. A beep occurs if the system receives a parity or phase error.
"I hate and love you so much" is something that I feel deeply
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There's a fun video of LGR experiencing some ... issues with his PCjr IR port.
The beeping was an intentional feature by IBM to inform you that you had a bad keyboard signal. A beep occurs if the system receives a parity or phase error.
"I hate and love you so much" is something that I feel deeply
- YouTube
Auf YouTube findest du die angesagtesten Videos und Tracks. Außerdem kannst du eigene Inhalte hochladen und mit Freunden oder gleich der ganzen Welt teilen.
(www.youtube.com)
Because I am very normal I needed to see if I can read the PCjr keyboard IR protocol with a light pen.
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Because I am very normal I needed to see if I can read the PCjr keyboard IR protocol with a light pen.
The IR signal is biphase-encoded. You can't really have the IR blasting all the time, and an absence of light isn't meaningful either, so quick pairs of light pulses signify meaningful data.
The first pulse is always 1, being the start bit. The start bit establishes the beginning of a series of 9 windows to follow, called bitcells. If a pulse appears at the start of a bitcell, it is a 1. if a pulse appears in the second half of a bitcell, it is a 0.
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@gloriouscow
Yes. It definitely will. -
The IR signal is biphase-encoded. You can't really have the IR blasting all the time, and an absence of light isn't meaningful either, so quick pairs of light pulses signify meaningful data.
The first pulse is always 1, being the start bit. The start bit establishes the beginning of a series of 9 windows to follow, called bitcells. If a pulse appears at the start of a bitcell, it is a 1. if a pulse appears in the second half of a bitcell, it is a 0.
The scancode is sent LSB first, after a start bit, and a parity bit follows.
So our scancode is 0b0001_1110 or 1E.
What key is that?MartyKey::KeyA => Some(0x1E),It's A! So, I assume that if I wire up the light pen to the keyboard port, we can use it as an IR receiver.
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The scancode is sent LSB first, after a start bit, and a parity bit follows.
So our scancode is 0b0001_1110 or 1E.
What key is that?MartyKey::KeyA => Some(0x1E),It's A! So, I assume that if I wire up the light pen to the keyboard port, we can use it as an IR receiver.
This shouldn't really be a major surprise to anyone, considering the light pen is essentially made of the same things - a photodiode and some filtering circuitry.
But it's just stupid enough to make me happy.
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