Access
A switch user requires:
Switch based software:
has switch access programmed in (the program itself monitors the status of the
various registers) either monitoring the serial port,the Keyboard buffer,or mouse button flags.
Serial port switches:
responds to the program monitoring the signals from the serial port.
requires a switch switch box which plugs into the serial port (com1 or com2) on
the computer.
Some software responds directly to keyboard input (e.g.Space/return in
Internet Explorer)and the switch connection has to operate through utilities reading the keyboard buffer or the mouse buttons and pointer positions.
Some switch operated software operates through the software monitoring the status of the mouse buttons.
Switch access is generally via a mouse extension box (Semerc mouser etc).
3. Keyboard activated software:
responds to a selection of keyboard entries
ie. space and return to move through hyperlinks in Internet explorer.
Some switch written software has space/return programmed as set input keys.
Switch access requires hardware to connect switches to the keyboard usually an
additional hardware which connects between the computer and the Keyboard.
difficulties/advantages to each method:
1. Serial switch access:
Requires a hardware component.
Requires switch software that is written to read the serial port and respond
appropriately
Will not work with standard mouse driven software unless additional
programming.
There has been considerable difficulty with differring hardware serial ports on
computers with modification to the hardware to allow it to work universally
(this is now completed). Some computers have two serial ports some have one
(some portables have none). The serial port on most computers is used for
connectivitity with other devices (modems, networks).
Is limited to two seperate/direct switch inputs *??*
2. Mouse switch access
requires a hardware component.
requires switch software to monitor the mouse clicks.
Works with all standard mouse driven software.
Is limited to two seperate/direct switch inputs.
3. Keyboard switch access
Requires a hardware component
requires switch software to monitor the keyboard input.
Can work with all software since all input can be echoed by the keyboard.
Is unlimited in seperate/direct switch inputs and can use strings/macros.
solution 1
Using different hardware to allow complete access via switches you would need a
switch serial box, a keyboard switch box and a mouse switch box.
You then have to change the physical switch connection according to the program
(ie plug/unplug according to whim/use, employing the well known technical
operating technique of Repeat:plug/test/unplug/plug/test: until success)
solution 2
Use a single hardware box which has hardware connections to the keyboard.
Keyboard connection can operate as the two mouse switches (easy via the
keyboard) and it might be able to operate as serial switches (?)
(but Stuart Tyrell tells me its nigh on impossible to do this on a PC)
It can work flexibly with keyboard inputs (space/return for Internet Explorer
etc and other combined keystrokes (either prewired as in Don Jonson or
programable as in Keyswitch+, and Intellikeys).
It can be used to input strings or any keyboard command sequence (macros).