Bus specifications

EDT designs and manufactures boards for a variety of bus specifications and form factors, including PCI ExpressPCIPMC, and CompactPCI.

PCI Express, today’s most widely used bus specification, was designed to replace the older PCI / PCI-X specification (which had less speed and bandwidth), but its mechanical and electrical specifications are different – so PCI Express boards won’t work in a PCI / PCI-X slot, or vice-versa. However, many of EDT’s PCI Express boards are functionally backward-compatible with their PCI predecessors, so applications originally written for an EDT PCI board often will work unmodified with its PCI Express counterpart, requiring only recompilation and relinking with the newer libraries / headers. Applications linked with current EDT libraries will also continue to work with the older PCI boards.

PCI is the predecessor to PCI Express, and PCI slots are still present in many Intel and AMD based computers. PCI-X is a “superspec” of PCI and supports bus clock speeds of 66, 100, 133 and even potentially 512 MHz. EDT’s first PCI boards were 33Mhz boards and would run at their rated speed in any PCI or PCI-X bus. Later boards were 66Mhz and run at their rated speed in any 66Mhz or faster PCI or PCI-X slot. They will also run in standard 33Mhz slots but with reduced maximum throughput. However, because of the bridge chips used in PCI Express, it is rare to find a modern PCI Express computer that has PCI slots faster than 33 MHz.  For more information and specifications, go to www.pcisig.com.

PMC and CompactPCI are essentially the same as PCI but in different form factors. They are electrically the same as the PCI bus, but the shape of the boards and the bus connectors are different. Designed for ruggedized implementations, the PMC and CompactPCI form factors provide a secure mounting platform for PMC VME and CompactPCI mezzanine boards. PCMCIA to PMC bus extenders also are available. EDT’s PMC and CompactPCI products use the same software, firmware, and device drivers as their PCI and PCI Express counterparts, and any applications written for EDT boards in one form factor will work on equivalent products in other form factors.

Designed by Sun in 1989, the legacy SBus board was for many years standard I/O interconnect for Sun computers, which typically run under the Solaris or SunOS flavor of the UNIX operating system. Our legacy SBus products have been discontinued and we can no longer provide support for any SBus products or Solaris drivers.

Currently, EDT device driver support includes Linux ™ and Windows 7, 8, 10 and legacy XP. For some products, MacOS support also is available.