Changes

'''Record''': The basic unit of data access in CP/M, 128 bytes in size. This was the standard size for transferring data between memory and disk.

'''Block''': A group of records, 1 KB in size. Blocks were used to improve disk access efficiency by reading/writing multiple records at once.

'''Extent''': A group of blocks, 16 KB in size. CP/M used extents to manage file allocation, with each extent corresponding to a portion of a file on disk.

'''Sector''': The smallest physically addressable unit on a disk, 512 bytes in size on Amstrad CPC. CP/M accessed the disk at the sector level, though users typically worked with records.