Keyboard Connection for Programming
To program a keyboard TA59 (i.e. download keyboard tables rsp. firmware)
it makes sense to use an external keyboard wedge. The wedge is
connected to the BEETLE system (or a PC with Mini-DIN connector). The
TA59 is connected to the wedge together with a Standard PC keyboard to
allow alphanumeric input. External wedges may have one of 3 different
behaviours:
n
Wedges with Flip-Flop behaviour: They switch the direction of output to
that keyboard, where the last input came from.
n
Wedges with Mono-Flop behaviour: They have a primary and a
secondary connector; normally the direction of output is switched to the
keyboard connected to the primary connector; when an input occurs from
the keyboard connected to the secondary connector, then for a short time
the direction of output is switched to the secondary connector to route
commands issued as a result to the right addressee, as e.g. switching
LED states.
n
Wedges with manual switch: Here the switch is done by hand, which may
be more intricate, but more transparent from an operator’s point of view.
Only wedges with Mono-Flop behaviour or with a manual switch are usable.
Unfortunately wedges with Mono-Flop behaviour are not very common.
Therefore in most cases wedges with manual switch will be used. The
wedges are available at a specialised store.
Never connect a keyboard TA59 for programming (of keyboard tables rsp.
firmware) to the secondary connector of:
n
a TA85P
n
a TA58P
n
or a SNIkey
The rsp. data would not be sent to the TA59. Rather they would be sent to
the TA85P, TA58P or the SNIkey. Programming leading to a fault would be
the minor problem. Even worse is that the TA85P, TA58P, or the SNIkey
would be programmed with wrong tables.
17
KEYBOARD CONNECTION FOR PROGRAMMING
