Discover the delights of your user port
INTERFACE is a combination hardware and software package based
around the user port.
It requires the full complement of 32k of RAM to run and, of
course, a user port.
The small printed circuit board is attached to the BBC Micro
via two feet of ribbon cable. Each line from the user port has
an LED attached, green for the data lines and red for the control
lines.
There is also a switch for each line, as well as an on/off switch.
These switches are of the "dual in line" type and can
be a little fiddly to operate but you can use them quite easily
if you push them with a sharpened pencil.
The software package consists of some 22 pages of information
about the VIA that makes the user port connection of the BBC Micro.
Some of the pages are interactive, allowing you to see the effect
of writing numbers to the port (the lights come on) or reading
data from the port (by moving the switches).
The piece de resistance is a full screen display of all the
registers in the VIA, allowing you to alter any of them easily.
The description of interrupts was a little sketchy with an example
of how a hypothetical Basic statement might be structured to respond
to one. However, no applications are given or even hinted at.
The data in the pages of multicoloured text are brisk and to
the point, in the same style as teletext. However, the interactive
element will allow a complete beginner to gain insight into some
of the delights of the user port.
Interface is produced by Electronic Developments Services and
costs £25.
Mike Cook
