On Fri, 25 Jul 2008 19:03:06 +0200, SP1WSC
wrote:

- some snippage -

Yes - the manual provides the basics and explains how to construct the
packets etc. What is missing though are the methods of handling the
memory banks. It even doesn't say how to read/write memory locations (I
may suspect that user memories are to be accessed by reading/writing
specific hardware memory addresses). And I have read somewhere that
there is a full specifications document, which covers these topics plus
there is even more - some undocumented features, which can be accessed
this way. I am looking for at least the specs that would allow one to
deal with user memories. FT-897 is a good choice - I have to deal with
FT-857, which is supposed to be fully compatible, but also with VX-7R,
which almost certainly is not.

I haven't considered the memory banks at all, I guess because I don't
use them.

An email to VertexStandard about additional opcodes received a
response in minutes. Unfortunately they can provide nothing beyond
what is in the manual. Port sniffing has revealed some additional
command structures and an understanding of why the documentation is so
limited.

An example is controlling the DNR/DNF/DBF features. A single command,
0x00 0xA8 0x?? 0x00 0xBC
is used to manage the combined state of the three controls. If byte[2]
is 0x9F sending the command will result in all three controls being
on. If that byte is 0x9D the resulting state will be the DNF and DBF
are on and the DNR is off.

The command
0x00 0xA8 0x00 0x00 0xBB
is used to request the state of the three controls. The first byte of
the response describes the current state. 0x90 indicates that none of
three are on.

The three controls present eight possible states. Explaining how the
command values relate to the various possible states without getting
into the complexities of state management only works if the audience
understands state management. The published documentation is targeted
at the lowest common denominator and avoids having to explain how
computers work.

73 de n4jvp