In a recent note, "Shmuel Metz (Seymour J.)" said: > Subject: Re: NL Usage for Tapes > > >Someone asked the question about what good are reading tapes NL. > >There are valid reasons and these go back to the early years before > >diskettes, etc, when people wanted to tansfer data. Early, early on > >the universal mode of transfer was 7-track tape, BCD, Even-parity > >with no labels. > > Even parity universal? I'm practically positive that you go back to > the 7090 and 7094, where odd parity was the norm. > A counterexample:
In the late 1960's I was working for a physics research project using a CDC 6400. We had begged some raw data from a sibling project using a 360. Partly to avoid loss of precision in binary->display->binary conversion, and largely because experience had taught me that the CDC FORTRAN display->binary conversion was prohibitively slow, I asked for a binary tape -- I had read the PoOp enough to know that I could easily and efficiently convert the floating point format with a CDC 6400 assembler program. A research associate with OS/360 experience told me to request TRTCH=C (CDC supported only 7-track at that time). The tape arrived illegible. Anxiously, the PI put me on a plane to the other site. After some RTFM and job log inspection, I learned that my counterpart had used TRTCH=TE; even (E) was the presumptive mode for data transfer. I insisted, "No, I want TRTCH=C." "But that will leave 8-bit bytes spanning 6-bit data frames on the tape; you'll never be able to process it on foreign equipment!" "You underestimate me." After a few phone calls, and with the authority of my PI, I got the TRTCH=C tape. I was able to convert and process it. So, yes, in days of yore, apparently one programmer considered even parity universal. -- gil -- StorageTek INFORMATION made POWERFUL ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
