Module Board Test & Measuring Module PC Computer Motherboard Debug Postcard Analyzer PCI and ISA 4 digit PCI analyzer:standard PCI and ISA interface,easy access to desktop PC. Standard PCI and ISA interfaces for easy access to desktop PCS. 4 digit display,the first 2 digits indicate the current error code,and the last 2 digits indicate the previous error code. PC Diagnostic 4-Digit Card fully compatible with any kind motherboards which has the PCI and ISA bus slot The POST code display is made up of a dual, dot matrix hexadecimal read-out that display's Power On Self Test (POST) status codes.