Motorola Computer Group stands to become the most influential of the troika backing the bus, which combines a small form factor with PCI compatibility. But despite expected support from a major telecommunications vendor and a large software company, some observers believe PC-MIP still lacks broad support among board makers, and could wind up as one more niche standard in a market of consolidating options.

Board makers SBS GreenSpring Modular I/O (Menlo Park, Calif.) and MEN Mikro Electronik (Nuremberg, Germany) will join Motorola Computer Group (Tempe, Ariz.) in rolling out PC-MIP products. Sources said that having market leader Motorola in its corner may be enough to drive the bus to success.

PC-MIP "comes close to being the ideal mezzanine for industrial or embedded CPU vendors," said Kim Rubin, chief technology officer for SBS Technologies' Computer Group, of which GreenSpring is a part. "It's real now," said Rubin, who expects the mezzanine to quickly achieve critical mass.

"You need certain basic functions to make this thing a viable solution, and we're at that point," said Jerry Gipper, marketing director at Motorola Computer Group. In his view, having products available from Motorola, GreenSpring and MEN means PC-MIP already has critical mass.

Not long ago every CPU vendor had its own mezzanine, but now things have boiled down to basically just two: the small-form-factor IndustryPack; and the PCI Mezzanine Card (PMC). At this point, "It seems a little insane to be introducing a new type of mezzanine into the marketplace," said Bill Kortanek, sales manager at Concurrent Technologies Inc. (Cincinnati).

Yet Kortanek said customers have been looking for a PMC-like mezzanine that's not quite as big, "so there is probably somewhat of a market out there" for PC-MIP. "The real advantage is that you can apply more than two of these on a board, but then you may have new cooling issues to consider."

Indeed, the mezzanine's trump card is its functional granularity. As many as six of the 47 x 90-mm boards can comfortably reside on a PCI board or 6U-size Eurocard board like VMEbus or CompactPCI, and as many as three on a half-size PCI board or 3U Eurocard. That's in stark contrast to the 74 x 149-mm PMC: only one PMC board fits on 3U, and two or three is the limit for 6U. On the other hand, said Joe Norris, president of PMC specialist Technobox Inc. (Mount Laurel, N.J.), PC-MIP provides insufficient real estate for some functions and for the many roll-your-own PMC boards OEMs make for their own systems.

PC-MIP arose from a cooperative effort by GreenSpring and MEN to craft a common PCI-compatible follow-on to their own mezzanine buses: IndustryPack and M-Modules, respectively, both ANSI standards.

Though the bus was unveiled a full year ago, rollout was delayed due to problems in the initial mechanical design for the boards, said Rubin of SBS Technologies. That led to a six-month "rethink and redesign. Going through three revs of the mechanicals really slowed us down," he said.

The companies' goal was to have less-expensive mechanicals than PMC and to solve a PMC "tolerance build-up" problem by incorporating what Rubin called a "floating mount."

"We did a first pass with spring clips and it worked pretty well, but we couldn't get modules with RJ-45 jacks installed without removing the front panel," said Rubin. "That's unacceptable for users, so we went back to the drawing board and came up with a different system." With the cooperation of Schroff Inc. (Warwick, R.I.), MEN recently put the finishing touches on the scheme, Rubin said, and new drawings are due out momentarily.

Real-estate issues aside, the success of PC-MIP will be gated by the availability of different functions and their relative cost. The first products out of the chute are a Compact PCI carrier board and four PC-MIP boards from GreenSpring; SCSI and video PC-MIP boards from MEN; and a VMEbus single-board computer from Motorola with PC-MIP expansion sites.

GreenSpring's first boards — Fast Ethernet, 32-channel digital I/O, 64-Mbyte EDO DRAM and 64 Mbyte flash memory — will be joined in December by a second wave, said Robert Perez, the company's PC-MIP business development manager: a MIL-STD-1553 interface, octal serial boards in RS-422 and RS-232 versions, a high-speed serial board and a PC-MIP carrier board for PCI.

"Our goal is to have at least 20 modules available by the middle of 1999," said Perez. The road map includes PC-MIP boards for A/D, D/A, optoisolated digital I/O and video, he said, along with carriers for 3U CompactPCI and 6U VMEbus.

PC-MIP carrier boards "will initially be about 25 percent more than an IndustryPack carrier," said Rubin. "But we think that by the end of 1999, it will be cheaper. You'll be able to get jellybean-type functionality without having to pay the high price of PMC, and we expect it to be cheaper than IndustryPack for similar functionality because it costs less to manufacture."

Perez's price list bears this out. A GreenSpring IndustryPack board with 8 Mbytes of flash memory goes for $1,050, while its 64-Mbyte PC-MIP board is $1,500.

An IndustryPack with 10-Mbit Ethernet is $590, while the autosensing 10/100-Mbit Ethernet PC-MIP board is $350. GreenSpring's CompactPCI carrier is being introduced at $595.

Follow the leader
For its part, Motorola Computer Group, VMEbus market leader and a serious player in other standard buses, is also giving PC-MIP a boost.

"I really like PC-MIP because it solves problems I have with the other two [mezzanine buses]," said Gipper. The problem with IndustryPack has to do with front-panel I/O access; with PMC, the issue is the number of mezzanine boards that fit on a baseboard.

"We see benefit in how [PC-MIP] bridges the gap" between the other two, he said.

The MVME2100 Series boards the company will announce at the Embedded Systems Conference are based on Motorola Semiconductor's new PowerPC 8240. The design has one PMC site on board and three PC-MIP sites, and it supports a companion I/O board for adding one or two more PMCs. This is a "ground-up design," said Gipper, not a respin.

"It's very similar to the step we took when we first came out with the MVME162," a breakthrough CPU board of the mid-'90s that represented Motorola Computer Group's first use of IndustryPack for modular I/O.

Like other bus-board vendors, Motorola will continue to support IndustryPack and PMC.