[blater]

Depends on context. In the early days many s100 users assembled the boards themselves and doubtless wouldn't have blinked any eyelid at hacking 8080/z80 bios code if they needed to (I remember the first kid at school to get a computer around that time, programmable with physical switches, binary LED display). By the time the commercial software market for CP/M became established with killer apps like word star, the users would have been rightly horrified by bios hacking.

[yuhong]

Of course, MS was also not as willing to provide the MS-DOS OAKs/BAKs to random users than DR was with CP/M. When they finally stopping copying the model before OS/2 1.0 was released, they still did things like putting the floppy and hard drive drivers in the same file.

[EvanAnderson]

Reference for people like me who didn't recognize the acronym OAK: "OEM Adaptaion Kit", <http://www.os2museum.com/wp/ms-dos-oaks/>

[yuhong]

And BAK stands for Binary Adaptation Kit.