Operation

Implemented

To Do

Progress

Screen Shots

Download PCITVText

Download Patch


 Only of interest to beta 
 testers, a small patch 
 for the module, to allow 
 operation with Nvidia FX 
 series graphics cards 

PCITVText is an application to decode and display teletext data from a Pinnacle PCI TV Card fitted to an Iyonix computer. It may well work with other cards which use the Conexant BT878 chip but has not been tested on anything other than the Pinnacle cards. If you already have Simon Wilson's PCITV application working, then PCITVText should also work.

Unlike most previous implementations of teletext on RISC OS computers, which use hardware to process the raw video signal into a recognisable ASCII data stream, Pinnacle do not provide this level of extraction so this program does the whole operation in software from the digitised video signal.

Once activated, capture of text pages to memory is a background, interrupt driven operation. All transmitted pages (including hidden pages) are written to memory as received and after approx. 30 seconds virtually all pages for a given channel will have been captured, allowing instant access to any given page. Where rolling pages are transmitted a new page overwrites the previous one, there is currently no storage for individual rolling pages

The decoder currently supports most of the TeleText Level One Features. Other features will be added once the quality of operation of the basic decoding engine has been confirmed by the beta testers

The current situation is that the decoding engine is not quite as good at decoding pages as a standard TV connected to the same terrestrial aerial. Text from a digital satellite receiver where that receiver provides VBI text re-insertion e.g. a Sky Digital box is also now working.

The software is currently of beta quality and requires more work before a general release is made.