Ajay Bhatt & The USB

HARDWARE PROTOCOLS
Trace the evolution of Universal Serial Bus, mastering polling, interrupts, and plug-and-play device handshakes.
PC Back Panel
120V AC
LPT1 Parallel
PS/2 Mouse

Dot Matrix Printer

Needs Data & Power

OFFLINE
Drag Data Cable
Drag AC Power
INTERFACEIEEE 1284 (Parallel)
IRQ LINEIRQ 7
POWER120V AC (External)
SPEED150 Characters/Sec

Ball Mouse

Data Only (Draws Power)

OFFLINE
Drag Data Cable
INTERFACEPS/2 Mini-DIN
IRQ LINEIRQ 12
POWER+5V DC (Bus)
POLLING60 Hz
Status: 0 cables connected

1995 Wiring Task

Grab the plugs from your devices and drag them to the correct ports on the back of the PC.

The Problem:

  • Every device has a unique, incompatible plug.
  • Data cables don't carry electricity, so you need giant power bricks.
  • The computer crashes if you don't configure hardware interrupts correctly!