CompuServe Messages

Phoenix did the first clean room BIOS. When the roms were duplicated, IBM did press it quite strongly; they put several mfgrs out of business. Everyone rushed to get hold of a clean room BIOS, rather than the knock offs previously used. IBM is also famous for agressively protecting its patents and copyrights through lawsuits and lawyers. Most computer companies are paying IBM royalties on one or more of IBM's crown jewel patents. (Did you know they had a patent on DMA ?) Companies do not do this willingly. IBM didn't choose not to protect the PC. There just wasn;t much they could do about it given the simplicity of the hardware design (all off the shelf components), the simplicity of the BIOS (fairly easy to reverse engineer in a clean room environment), the public availability of the OS. IBM certainly wasn't happy about it…remember the licensing arrangements for MicroChannel, where, ti (to) get a license they wanted each computer company to pay royalties on all PC compatible machines made, microchannel or no ? To clone a MAC would require considerable investment on the part of the clone maker in reverse engineering the toolbox rom. (256K or 512K of code is nothing to sneeze at). To clone an Amiga would require comparable software effort, plus the erstwhile clone maker would have to reverse engineer three full custom chips, a couple reasonably complex gate arrays, not to mention the 8520s (which are Commodore Semiconductor custom parts). The investment required is much larger. So much so its hard to justify it. (for either machine, actually; that's why most Mac clones seem to require the availability of actual Mac roms, thus saving all development effort) andy