FAQ'S

Please note that due to the nature of the Consortium we are unable to recommend any company product over another. We can also not comment on specific company boards or parts. For questions those types of specific questions, please contact the original vendor.

Q. The PC/104 specification refers to the IEEE P996 ISA bus specification. I contacted IEEE to get a copy of this specification and was told that this specification was withdrawn and thus does not exist. Where can I obtain an ISA bus specification for protocol and electrical design?

A. The P996 specification project has been cancelled by IEEE and the draft specification is no longer available. A list of references on the ISA(P996) bus appears below. In particular, the book entitled ISA Bus Theory and Operation, available from Annabooks, provides good coverage of what was the P996 specification. Annabooks also offers several other books that contain information on the ISA bus.

References:

"ISA System Architecture, 3rd Edition" by Tom Shanley and Don Anderson ISBN 0-201-40996-8
"Eisa System Architecture, 2nd Edition" by Tom Shanley and Don Anderson ISBN 0-201-40995-X
"Microcomputer Busses" by R.M. Cram ISBN 0-12-196155-9
HelpPC 2.10 Quick Reference Utility, by David Jurgens
"ISA Bus Theory and Operation", Annabooks

Q. Can you please send me a price list on your products?

A. The PC/104 Consortium does not have products. The member companies of the Consortium can be contacted regarding pricing on their products.

Q. We are a company considering using the PC/104 standard in an embedded system. One big worry that we need to get answered, before even thinking of using this standard in our products, is: What is the future of PC/104 when Microsoft has announced not to support in the future the ISA bus (that is, PC/104)?

A. Despite the "PC99" recommendations of Microsoft and Intel, which eliminate the need for the ISA bus, Intel (and others) have promised to keep current ISA chipsets alive for at least five to seven years. There are many PC/104-based "real world" interfaces from hundreds of manufacturers, and these are not going to become obsolete just because the desktop PC does not require or use ISA slots anymore.

Functions such as analog I/O, digital I/O, motion control, and custom application interfaces can still take advantage of low cost and design simplicity of the ISA bus. Contrary to Microsoft's and Intel's marketing focus, the 386 and 486 processors are still the most popular in PC/104-based embedded systems, with Pentium designs only recently becoming available on a wide scale.

The PC/104 Consortium added PCI to PC/104, resulting in PC/104-Plus (= ISA bus PLUS PCI bus), in order to allow high speed processors such as the Intel Pentium to utilize higher speed I/O bandwidth to achieve their full potential in embedded systems. The PC/104-Plus standard, with its PCI in addition to ISA bus, provides a long-term future for PC/104. Manufacturers of PC/104 modules now have three choices from which to choose, all within the industry standard PC/104 form-factor:(1) ISA bus only; (2) PCI plus ISA buses; and (3) PCI bus only.

Despite the popularity of PCI in desktop PCs, there will continue to be an advantage to having two separate buses in many embedded system applications: PCI bus, for high speed block data transfers (e.g. video, networking, disk storage); and ISA bus, for byte-oriented (e.g. real-world data acquisition and control).

Today, 80% to 90% of PC/104 form-factor modules are using ISA bus only. Within approximately five years, it is likely that there will be greater than 50% using the PCI bus. It will probably take ten years before the situation of today is reversed, with 80% to 90% of PC/104 form-factor modules using PCI bus only. Even so, ISA will still be supported on PC/104-Plus modules, ten years from now.

Q. Do you have knowledge of any marketing reports on PC/104 that are available?

A. No one tracks "PC/104" in depth. However, the following have published surveys in the past that include PC/104 information:

VDC Research -- 508/653-9000, Chris Rommel
Embedded Systems Research -- 541/754-9310, David Shear
International Data Corporation (IDC) -- 508/935-4694, Paul Zorfus

Q. We are working on a design that includes PC/104 and need some technical help. What do I do?

A. You may submit your question to our volunteer Technical Support staff by e-mailing it to them. They will get back to you with an answer.

Q. Are PC/104 ISA bus devices supported in Windows 7?

A. In modern versions of Windows (post XP), ISA bus support is deprecated. However, it is still quite possible to use an ISA bus device under Windows 7, provided that the following are true:

The device does not depend on ISA Plug-n-Play (e.g. base address is set by jumpers or DIP switches). Microsoft has phased out ISAPnP support in newer versions of Windows.
The device does not rely on an "in-the-box" Windows driver (e.g. an NE2000 Ethernet controller). Microsoft has removed several legacy drivers that were previously bundled with Windows.
The peripheral board vendor has provided Windows 7-compatible driver software. Windows 7 includes several security features that were not present in XP, which may affect compatibility with older drivers.

If you plan to use an ISA bus device under Windows 7, it is recommended that you contact the peripheral board vendor to confirm compatibility with Windows 7.