Logic Analyzer Connected to PS/2 Keyboard

I got a logic analyzer today; a Hewlett-Packard 1650B (introduced in 1987). I've never used a logic analyzer before so I figured I'd connect it to a PS/2 keyboard. It's pretty damn awesome.

I suck at narration, so here's the gist: When a key is pressed or released, an 11-bit data packet is sent serially, with the data line being read on the falling edge of the clock pulse. The first bit is a start bit. The next 8 bits denote the scancode, least significant bit first. The last two bits are a parity bit and a stop bit.

Category:

Science & Technology

Tags:

• logic
• analyzer
• ps/2
• keyboard
• electronics
• hp
• 1650b
• avr
• atmel
• atmega168

[exodus21v20]

@74hc595

Why do you need the circuit on the breadboard? What's it doing?

[74hc595]

@exodus21v20 It's a microcontroller circuit that shows the scancode and ASCII value of the key pressed on a small display. I demonstrate it in an earlier video.

[rostlaur]

S U P E R B !

The idea of a keyboard interface is a 10+++++

[int0x13]

please tell me which key from the keyboard do you press during the video?

[PierpaoloSpaggiari]

Thanks for sharing...!

[sonick808]

nice kit, color me jealous

[Esperantanaso]

This was informative and useful.

[yanava]

Pretty good piece of equipment, congratulations!