TELEVISIONS AND MONITORS.
The BBC range is pretty versatile when it comes to connecting some sort of
monitor. It has RGB, composite and RF for televisions (except compact).
You can use practically any monitor you can get your hands on except the
majority designed for PCs. The earlier the PC monitor the more likely it
is to work. Anyway theres a lot of monitors available at carboots etc
which are ex-office and sold for a couple of pounds. Many of these green
screen monitors were originally meant for dedicated wordprocessors or CPM
machines. Plus of course there are far more recent ones available. The
following is a list of monitors that will work with the BBC and can be
picked up cheap at car boots.
These colour monitors originally supplied with the Amstrad 464, 664 and
6128 will work directly with the BBC. You don't need a conversion cable
but you might want to extend the cable that comes out of the monitor as
its very short. The monitor has a 5V supply coming out of it which you can
disconnect or tape to one side. The 644 also has a 12v supply on the front
of the monitor. You could actually in the case of the 644 make a
conversion cable to power a disk drive. The monitors are very simple and
have a low resolution display. This is perfectly acceptable for games use
with vivid colours but 80 column is less agreeble but still better than
using a tv with an RF connection. These monitors will also work with
Amigas, STs, Archimedes etc.
These are the green screen monitors supplied with Amstrad 464,664 and
6128. Don't plug the BBC directly into these. The 5V of the BBC's monitor
port will link up with the luminance pin and could do some damage to the
monitor. You need to make a conversion cable with a phono on one end for
the BBC and a six-pin DIN socket on the other.
Well most of these were meant for the BBC. There are other models designed
for other computers like QLs. But they should all work with conversion
cables. The exceptions being any designed for PCs but these are generally
later models. Even analogue models meant for the Archimedes will work with
resistors in the cable. Some Microvitec models originally meant for TTL
RGB like the BBC can be altered by internal links to work with Archimedes
and Amigas etc.
Well theres just so many its hard to know where to start but again most
Portable televisions with SCARTs will work either with composite or RGB.
Other televisions with monitor ports will work but it would be handy to
know the connections before you buy it, although they may be printed on
the PCB by the monitor socket.
What you want to see.
A phono input. If a monochrome monitor has a single phono input as well as
any other connector it will almost definitely work. PCs don't connect by
50Hz vertical sync printed on the back. Another good sign. If in
combination with the above it will definitely work. However it could still
have separate syncs if it has a multipin connector. Both vertical and
horizontal which may cause difficulties. Some monitors with separate syncs
will still give a stable picture if the BBC's sync is provided to just one
of the two syncs or shorted to both. Diodes could be used to aid
compatibility. Allowing the BBC's sync to enter both connections without
actually allowing the vertical and horizontal to be shorted together.
Ask what computer its been used with. If its a PC, Commodore 128, Atari
ST(monochrome high res mode) there will probably be difficulties. If its
an 8bit computer like Atari XL, Spectrum, Dragon, MSX, C64, Vic20,
Memotech, Einstein etc it will be alright.
Never pay much for monitors at carboots. Ten pounds or less as they could
be totally duff.
A brief description of output types.
Composite (monochrome). Just the luminance. Ideal for wordprocessing for
long periods with no headache.
Composite (colour). Not much different to using a tv lead except it
doesn't drift off channel.
RGB (the business!). Totally solid colours with no grain. Teletext quality
displays. Need medium res monitor for 80 column work. Monochrome is still
better for long sessions of wordprocessing.