The VDIS is an economic test and diagnosis board for the VMEbus. It displays all important signals and is a powerful tool for monitoring, debugging and service. It is a 6U one slot (4 TE) wide standard VME unit.
VDIS displays all data and address bits, the 7 interrupt levels and the bus controlling and power lines. For better visibility some signals are stretched. The use of the VDIS is straightforward. There are three operating mode switches on the VDIS. One of them (VD) allows the VDIS to generate a DTACK after a time-out, or addressing a 32 bit wide memory location (address selectable by dip switches) if enabled. The address modifier (AM) for the internal memory location can be set by dip switches also. If DH is enabled the signals will be latched upon a bus error (BERR). They can be reset by switching reset halt (RH). If display all (DA) is switched on, the signals are always latched between two VMEbus transfers. The enable halt (EH) function and a trigger are available on a connector for external monitoring.
