That, indeed, is how the Teletype 33 behaves. And 5-level teleprinters normally had separate CR and LF codes that acted in that way. TRS-80s used CR only IIRC. In fact they _sent_ CR only to the printer as standard, which could be a a problem if you had a non-Radio-Shack printer, or if you wanted to use an Radio Shack printer on some other machine. There were 'filters' for some TRS-80 OSes to add the LF. Most older printers had an internal DIP switch to set an 'Autofeed' -- that is to do a linefeed (as well as returning the carriage). There was also a pin on the Centronics connector to enable/disable this feature. IIRC the BBC micro has a operating system call to set the 'printer ignore character'. At power-on this was set to 0x0A (LF). I think the OS would try to send CR LF, the printer driver routine would then delete the LF so that only the CR got through (requring a printer that did an autofeed), then you could change the 'ignore' character to something else if the printer neeeded both CR and LF. The HP9866 is a thermal line printer (prinhead the full width of the paper, but only one dot high). From what I can deduce from the scehamtics, it ignroes CRs totally, when it gets an LF it springs into life and prints the contents of its buffer. I think I did, once. Really confuesed a bit of software I was using too... I beleive the original intention was that 0x7F would be _ignored_. The point being you could overpunch any characeter on paper tape to turn it into 0x7F (all holes), and thus you could effectively delete that character from the tape -tony