Kildall's BIOS 1345

CP-M's BIOS was radically different than what had been done for OS-8 and RT-11. At the time, you had to buttemble your OS-8 or RT-11 monitor along with the device drivers you were going to use. This meant that porting-installing on a machine with different peripherals required a bootstrapping process involving at least a functional buttembler-linker.

CP-M, though, was designed to be installed with "stone knives and bear skins" as the available tools. All you need is a front panel and knowledge of your disk controller and some time to toggle in the first BIOS, and then you could be up and flying. This is the one factor that led to its success in the less-than-completely-homogenous environment that microcomputing had in the mid 70's.

I'm puzzled by this statement. The BIOS abstraction was refined between 1.3 and 1.4 and 2.0 and 2.2 to make it easier to use disks that weren't 8" SSSD, and these also helped with hard disk usage too. So the details of the abstraction were improved upon, but really the abstraction level changed not at all.

Certainly users of later (turnkey) CP-M hardware never appreciated the toggling in of your first BIOS :-). In fact, I'm sure that 99% of them didn't even have access to their BIOS sources. I suspect that this is what you mean. But the BIOS was still there, just under the hood.

Tim.