🚀 go-pugleaf

In article <715264965snx@n5ial.chi.il.us>, jim@n5ial.chi.il.us (Jim Graham) writes:
> NOTE:  I am not exactly an expert on ibm mainframe things, spending
> most of my time on UN*X or dos, so I may be way off on this...but.....
 
> In article <1992Aug28.144526.27967@news.th-darmstadt.de>
> schrod@iti.informatik.th-darmstadt.de writes:
> 
>> That has nothing to do with ASCII or EBCDIC. Most DVI drivers assume
>> that IBM mainframes (I assume that they run either MVS or VM/CMS, not
>> AIX/370 ;-) store the files in fixed record files.
 
> I'm assuming that by ``record'' you mean a line of text in a plain old
> ASCII (errr, EBCDIC) text file.  well, the obvious solution is not to
> use fixed-length lines in the file (but then, ibm won't let you, will
> they?).  ok, so we're looking at a file where every last line of text
> will be precisely the same length, no shorter, no longer.  and we want
> to move a DVI file into this format....  shouldn't really be a
> problem....

Actually IBM will let you have a variable record format file no
problem. Catch is that you can't do random access reads on such a
file. This is important for dealing with DVI files.

Furthermore, without some clever hacking at the assembly level,
the program must know at *compile time* the record format of the
file that it's reading. Thus the facile solution of setting
record length to 1 (well actually, you could set it to 4 and get
correct results) will not work with most DVI translation
software--in fact, the only program I know that'll handle
Fixed-anything files is TeXrox which the original poster was
obviously not using.

As for why it's done this way, the answer is efficiency. It's
really actually done this way in DOS and Unix (among others) too,
but the operating systems hide that fact from you.

-dh

(Some days I actually _miss_ VM/CMS.)