CP/M, without a doubt the most popular OS for Z80 based systems with disk drives, and the main inspiration for MS-DOS, was an exception: "Files in CP/M can be

CP/M, without a doubt the most popular OS for Z80 based systems with disk drives, and the main inspiration for MS-DOS, was an exception: "Files in CP/M can be thought of as a sequence of up to 65536 records of 128 bytes each, numbered from 0 through 65535, thus allowing a maximum of 8 megabytes per file. Note, however, that although the records may be considered logically contiguous, they may not be physically contiguous in the disk data area. Internally, all files are divided into 16K byte segments called logical extents, so that counters are easily maintained as 8-bit values. The division into extents is discussed in the paragraphs that follow: however, they are not particularly significant for the programmer, because each extent is automatically accessed in both sequential and random access modes". (http://www.gaby.de/cpm/manuals/archive/cpm22htm/ch5.htm http://www.gaby.de/cpm/manuals/archive/cpm22htm/ch5.htm)