On 03/15/12 6:31 AM, James B. Byrne wrote: > I eventually managed to read the tape at 1600 bpi in raw > block format and from the headers determined that the > encoding was EBCDIC and that the tape had been created on > a CDC machine. if it was from a 70s' vintage CDC system, I'm sort of surprised it wasn't BCD, not EBCDIC... BCD was an earlier 7 bit character code. lucky that was 9-track, the CDC stuff I remember used 7-track tape, even MORE unobtanium. On 03/15/12 6:59 AM, m.roth at 5-cent.us wrote: > c) had you asked me, and only telling me the above, I would have told you, > with 95% (at least) confidence, that it was EBCDIC. actually, I dealt quite a bit with 9-track ASCII tape from that era... DEC, Data General, HP, etc systems were all ASCII based. I'd only expect EBCDIC if it was from an IBM system, or one of the clones like RCA. fun bit of personal trivia... my wife's first job out of college was at DEC as a new Technical Writer, and her first assignment was to sort out the Mag Tape subsystem for VAX/VMS 1.x and write first the internal design specs, then users documentation. VAX/VMS had excellent mag tape support, just as 9-track mag tape was fading into oblivion. fun bit of trivia #2: my very good friend is a hobby-machinist, builds scale working live steam trains when he's not doing hardware/software consulting jobs.... he has a vintage bridgeport mill which he grafted a 100VDC servo motor out of a high speed Ampex 9-track take drive as the Bridgeport came with a 3-phase motor and its rather hard to get 3-phase AC in a residential garage workshop :) This DC motor is smooth, powerful and quiet, and lets him run the mill at variable speeds without messing with the V-belts. -- john r pierce N 37, W 122 santa cruz ca mid-left coast