Anyone know the correct settings on a high-speed paper tape (specifically the GNT-5601) to get it talking to the Altair? I've got the Altair's third port (the ACR port) at 9600 8N1 but the punch tape machine's setup uses odd language about parity. On the reader side I've gone for no parity but on the punch side the manual asks "What PARITY should be punched on the tape? Applies to ASCII only. EIA parity is always odd. Roll through E/0/N (Even/Odd/None). The parity bit is the 8th bit on the tape. If No Parity is selected, the 8th channel will be blank." It's that last sentence that's bothering me: surely if there's no parity bit then the 8th channel should be punched with the 8th bit in the incoming byte, not "be blank"?
With these settings (8N1 @ 9600 baud) the CSAVE command in 8K BASIC manages to punch a tape, but its 8th channel really is blank throughout (there are 7 holes punched not 8) and this tape isn't readable with CLOAD. Programming the comm port on the tape punch I've gone for "Hardware handshaking disabled" since I know the ACR port doesn't use hardware handshaking.
Regards
Gabriel Egan