On Wed, 23 Jan 2013, John Day wrote:
> > > > IIR, Multics from several years earlier. I'd have to dig > > through old manuals to remember what CTSS did, but that system > > (and the IBM Model 1050 and 2741 devices often used as terminals > > with it) were somewhat pre-ASCII (and long before ECMA-48/ ANSI > > X3.64 and the VT100 and friends) and, IIR, sent and received > > shift and rotate codes rather than what we would normally > > consider character codes today. The character codes were just > > input to device drivers that dealt with device characteristics > > Multics was based on EBCDIC which had a New Line (NL) character but no CR or > LF. The ARPANET went with the ASCII standard. But I never forgave the ANSI > committee for taking left arrow out of the character set (as a replacement > operator). EBCDIC has NL (new line), LF and CR characters (hex 0x15, 0x25 and 0x0d respectively). EBCDIC was an 8 bit code easy to translate in hardware logic from punch card codes to the 8 bit code. Earlier IBM systems used BCD (sometimes called BCDIC) which was a 6 bit code which did not have CR or LF but had a subset of the EBCDIC style mapping from punched cards to computer code. IBM systems all implemented a record based file organization rather than the character stream of UNIX. So the BCD generation systems had a record mark charcter (and word mark) in the pre-S/360 days with BCD and file system level record tracking in S/360. IBM terminal devices (e.g., 2740, 2741, 1050, etc.) of the pre VDT era used a different character coding on the wire (not BCD). Might have been inspired by tilt/rotate, I don't know and never worried about more than getting the translate table right. Hardware communications controllers and later programmable controllers recoginzed the NL character and signaled end of line/record to the host computer. IBM lineprinters of the era were record/line oriented devices which printed about 132 characters per line and advanced to new like, page, etc. based on device specific commands and not data interpretation. ANSI line controls or IBM internal codes could be used in the first character of the line to pre/post space 0 or more lines for each print record. VDTs with long lines might have been inspired by line printers or just the idea that long lines were better. No experience there, but I'm pretty certain there were no 132 column punch cards in common use which would have influnced comody VDT designers. 80 and I believe 96 in S/3 days. Dave Morris