A US-based company that began advertising a Mac clone called "OpenMac" for US$399 said Monday that it was stunned by the response and couldn't take orders because its Web site had gone under.

Before its site went dark Monday, PsyStar was pitching an Intel-based system it said could be configured to run Leopard, Apple's Mac OS X 10.5. The machine, which was priced at US$399 minus Leopard, US$554 with it already installed, is powered by a 2.2GHz Intel Core 2 Duo processor, and includes 2GB of memory, a 250GB hard drive, optical drive and on-board graphics based on Intel's Graphics Media Accelerator (GMA) 950 graphics processor. The GMA 950 is part of several Intel chipsets -- notably the 945 series -- that are popular on PCs designed to run Microsoft's Windows.

The response to the OpenMac caught PsyStar off-guard, said an employee who answered the telephone's sales line Monday. "We didn't anticipate this reaction," said the employee, who identified himself only as "Mark."

He deferred other questions, asking that they be forwarded via e-mail. As of mid-day Monday, PsyStar had not responded to those queries.

On the now-offline Web site, PsyStar had bragged that it had "reinvented the wheel" by building a machine "that is completely operational with Leopard." The company also claimed that with some "minimal patching" users could install Mac OS X 10.5 on the system. "With the EFI V8 emulator it is possible to install Leopard's kernel straight from the DVD that you purchased at the Apple store barring the addition of a few drivers to ensure that everything boots and runs smoothly," PsyStar's site said.

EFI, for Extensible Firmware Interface, is a specification designed to replace the aged BIOS firmware interface that's been used on PCs for decades. Apple began supporting EFI when it introduced its Intel-based Mac line in January 2006.

PsyStar also contrasted its system -- which it had earlier, and only internally, called "PsyStar Alternative" before switching to "OpenMac" -- with Apple's lowest-priced model, the US$599 Mac mini. "The basic OpenMac is better than the most affordable Apple computer out now not only in price but in possibilities," said PsyStar's site. "The OpenMac sports a faster processor (2.2GHz vs. 1.83GHz), double the memory (2GB vs. 1GB), three times more hard drive space (250GB vs. 80GB) at almost half the price!"

Although Apple once allowed a limited number of computer makers to install its operating system on their hardware, it has banned the practice since 1997, when now-CEO Steve Jobs put the kibosh on the idea. In September 1997, Apple bought key assets of Power Computing, the primary clone maker, and as part of the deal shut off the company's right to make and market machines able to run Mac OS.

Monday, Apple did not reply to a request for comment on whether it plans to contact PsyStar to enforce its Mac OS X end-user license agreement (EULA), which bans its use on hardware other than that sold by Apple. "You agree not to install, use or run the Apple Software on any non-Apple-labeled computer, or to enable others to do so," Apple's current EULA reads (download PDF).

Among the questions posed to PsyStar were several related to how it would address Apple's EULA.

Although PsyStar has a "Sales" option on its voice mail, the company employee who answered the phone said they would not be taking orders over the telephone, and that customers would have to wait until the Web site comes back online.