Tony Duell wrote:
>> Tony Duell wrote:
>>> Texas CFxxxx numbers tend to be custom ASICs :-(. No chance of
>>> getting a data sheet on those.
>> *ACK.
>>
>>> What also bothers me is the lack of RAM. The Philips decoder uses
>>> the SAA5231 VIP (Video Input Processor -- this is essentially the
>>> 'data slicer' and is mostly analouge), the SAA5243 Teletext
>>> decoder/display chip _and an 8K RAM_.
>> There are Philips chips with built-in RAM, though. SAA5246 IIRC.
>
> I thought the 5246 integrated the VIP and the ECCT (Enhanced Computer
> Controlled Teletext -- the SAA5243) and still used an external RAM
> chip.
Oops - my bad. I think the SAA5281 has the RAM integrated, IIRC.
>>>> Anyone got a Ferguson T14T or Thomson TX91 service manual? I need
>>>> the part
>>> It's a bit modern for me :-(. However, a TV service manual is _not_
>>> going to include any info on the commands that flow between various
>>> ICs. You will not get a list of registers on the I2C bus and their
>>> contents, for example.
>> The thing that seems interesting is that the TTX controller IDs it
>> as an
>
> How do you mean? What exactly tells you it's an SAA52xx chip?
The I2C address is the same as some of the chips from the SAA52xx series.
>> SAA52xx series TTX controller. The original schematic that I had (a
>> VERY bad
>
> If you suspect it's a 5243 or similar, and if you know it's
> controlled by an I2C bus, have you tried enabling the external sync
> output by writing to the appropriate bit in one of the mode control
> registers and then tried looking for a composite sync signal on the
> pins of the larger IC?
I'm planning to build a video generator using a PIC and then connect Sync to
the Cub653, CVBS to the TTX board, then connect R.G.B. from the TTX board to
the monitor. In theory that *should* get me a picture. I've got an I2C
interface for my laptop that still works, so I have some way of controlling
it.
Later.
--
Phil.
philpem_at_dsl.pipex.com
http://www.philpem.dsl.pipex.com/
Received on Fri Sep 13 2002 - 01:38:01 BST