Implementation of the ISA Bus (de)Bugger expansion card sold as a DIY kit in the late 1980's in The Netherlands. This card was a assemble-yourself 8bit ISA addon card for PC and AT systems that had several tools to aid in low-level debugging (mostly for faulty BIOSes, bootloaders and system kernels...)

The standard version had a total of 16 LEDs (8 RED, plus 8 GREEN), two 7-segment displays and one 8-position DIP switch block on board for use as debugging tools.

The "Plus" version, added an extra 2 7-segment displays, as well as a very simple RS-232 serial interface that could be used as a mini-console terminal.