POST card

POST cards provide information even when a standard display is not available, either because connecting a monitor is impractical, or because the failure occurs before the video subsystem is operational.

POST cards are inserted into an expansion slot, and are available with connectors for the ISA (also supporting EISA), PCI, PCI Express, Mini PCIe (for laptops), Universal Serial Bus, or Low Pin Count bus, or for a parallel port.

Modern motherboards often do not broadcast POST codes to their PCI Express slots (PCIe switches only pass on transactions after having been configured to do so by the BIOS).

This may be supplied with cards, but becomes dated as later BIOSes are issued; more up-to-date information may be available on manufacturers'[2][1] and independent websites.

By the late twentieth century large scale integration, mass production made motherboards inexpensive components.

BIOS POST card for ISA bus. Two seven-segment displays show the POST-code. Four LEDs display presence of +/-5 V and +/-12 V.
BIOS POST card for PCI bus
BIOS POST card with connectors for the PCI (bottom), PCIe (top) and LPC (left 2 mm and right 2.54 mm) busses
Two POST seven-segment displays ("Q_CODE1" and "Q_CODE2", lower-left), integrated on a computer motherboard