7 Oct
2001
7 Oct
'01
12:57 p.m.
On Oct 7, 22:36, Philip Pemberton wrote:
On 7 Oct 2001 1:36:56 +0100 "Iggy Drougge"
<optimus(a)canit.se> said:
> Tony mentioned teletext chips a few days ago.
Don't know if those
perhaps
are
> only 8-colour, though. Tony?
The SAA5050 is certainly only 8-colour (plus attributes like flashing) and
as far as I know so are later teletext chips.
I've got an SAA5050. Anyone know how to use it
without the SAA5020 timing
generator?
Take a look at the circuit diagram for a BBC micro; it uses a 6845 for
timing and an SAA5050 to generate the teletext screen mode.
http://bbc.nvg.org/mirror/www.acorn.com/ftp/documents/circuits/
I've also got a Microvitec Cub 653 monitor. TTL
input, composite sync.
How
can I get Csync from Vsync and Hsync?
XOR them together; feed the unbuffered TTL outputs to a 74LS86 or similar,
and buffer the output with a transistor.
--
Pete Peter Turnbull
Network Manager
University of York