IBM, UNIVACSPERRY, BURROUGHS, and friends. Compare 1142
IBM, UNIVACSPERRY, BURROUGHS, and friends. Compare 1143
On 10 Jan 2005 18:58:44 -0800, Lawrence Statton N1GAK-XE2 The purpose of copyright is to benefit the public. Copyright is...
The particular issue I'm referring to here is that there isn't really a "newline" character in MTS as such.
Both "line" and "sequential" files are, basically, arrays of Pascal strings. No byte value delimits records.
The downside is that there's a maximum length to a record. 32,767 bytes for sequential files, and, originally, 255 bytes for line files (a later modification of the operating system increased it).
This made certain FORTRAN constructs work in a nonproblematical manner. Of course you can define database files in Unix as well, but the difference in how default text files worked did make things simpler for the ordinary programmer. It also meant that disk files looked like the simplest kind of magnetic tape file - with a gap between records - or like a deck of punched cards. (On the other hand, the Unix convention, which is also used, with different character combinations, in MS-DOS-Windows and the Macintosh, meant that disk files were more compatible with paper tape ... used a lot with DEC machines, but simply not used in the IBM world.)
The line file in MTS, of course, was one specific kind of ISAM file that was set up to be the default type of text file. This worked OK on a mainframe, and would still work on any computer with a hard drive, but it would cause excessive wear on floppies.
Alt Folklore Computers Newsgroups