[RTTY] BARTG 75 Sprint

[Kok Chen]

On Jun 13, 2010, at 11:59 PM, Joe Subich, W4TV wrote:

> Actually 8+start+stop to 5+start+stop.

For what its worth, there has never been an 8-bit version of the "ASCII" code.  

8-bit codes such as ISO-8859 added 128 more codewords to ASCII. Informally, the 8-bit codes such as ISO-8859 that have ASCII in the lower 128 locations have been ad-hoc called "Extended ASCII."  But the ASCII Standard itself has never been expanded to 8 bits.  

You can confirm this by Googling for the phrases "ASCII," "ISO-8859," "ISO-646" and "Extended ASCII."

For the USA, the codes allowed in RTTY is governed by FCC Part 97.309 "RTTY and data emission codes."

97.309(a)(1) relates to 5-bit Baudot, 97.309(a)(2) relates to 7-bit Amtor, and 97.309(a)(3) relates to 7-bit ASCII, which I quote:

> "The 7-unit code, defined in American National Standards Institute X3.4-1977 or International Alphabet No. 5 defined in International Telegraph and Telephone Consultative Committee Recomendation T.50 or in International Organization for Standardization, International Standard ISO 646 (1983), and extensions as provided for in CCITT Recommendation T.61 (Malaga-Torremolinos, 1984) (commonly known as ASCII)."

7-bit ASCII, 5-bit Baudot and 7-bit Amtor are "pre-approved" data encodings by the FCC.  If you want to use 8-bit codes (not specifically mentioned in Part 97), I think you'd defer to 97.309(b).  

Part 97 is of course only for US hams.  Many countries are more relaxed with what can or cannot be transmitted in the Amateur bands, while some countries are more restrictive.

cocoaModem currently implements both Standard ASCII when selected to 7 bits, and ISO-8859-15 when selected to 8 bits.

73
Chen, W7AY