3 ms·

> Unlike CP/M 2.x, CP/M 3 allows for banked memory and disk data/directory buffers, resulting in a lot more usable memory for applications (Transient Program Ar

> Unlike CP/M 2.x, CP/M 3 allows for banked memory and disk data/directory buffers, resulting in a lot more usable memory for applications (Transient Program Area) and faster disk access. Sounds a lot like what MSX-DOS 2.xx does as compared to its predecessor. FYI: both versions of MSX-DOS are partially CP/M compatible, such that a # of applications running on it are slightly- or unmodified CP/M programs. Not unimportant given how much quality CP/M software already existed in early '80s. One oddity resulting from this: some OS calls read or write files in multiples of 128 byte 'records' (regular MSX-DOS calls do handle exact file sizes though). Just guessing: sector size of ancient 8" floppies, or something like that?

schlopper 3y ago
Interesting - CP/M has a fixed sector size of 128 bytes. In CP/M 2.x, if your physical sectors were a different size, you'd have to implement deblocking code in your BIOS. CP/M 3.x still used 128 byte sectors, but supported specifying the physical sector size and would do the de-blocking for you. I'm guessing MSX-DOS uses the 128 byte records/blocks to make it easy to read foreign disks and to be able to create disks readable on other platforms?