UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Homemade Teletext decoder (based on Mullard Module)

1980s_john · 13th Dec 2020, 11:48 pm

Thanks for heads up on the Television articles. I can't remember where I bought the module from but £15-£20 seems right. Most of the design in the Television adapter is about the the keyboard interface. I used an EPROM to map from the 4x4 telephone keypad to the 7-bit code that the Mullard required as shown in the Dec 1986 article (I was limited to 14 different codes so picked what I thought were the most useful). As my TV had RGB + sync + blanking input there was no need for a UHF modulator. It really was a hack but it worked well.

Regards,
John

13th Dec 2020, 11:48 pm	#3
1980s_john Triode Join Date: Apr 2005 Location: Ipswich, Suffolk, UK. Posts: 31	Re: Homemade Teletext decoder (based on Mullard Module) Thanks for heads up on the Television articles. I can't remember where I bought the module from but £15-£20 seems right. Most of the design in the Television adapter is about the the keyboard interface. I used an EPROM to map from the 4x4 telephone keypad to the 7-bit code that the Mullard required as shown in the Dec 1986 article (I was limited to 14 different codes so picked what I thought were the most useful). As my TV had RGB + sync + blanking input there was no need for a UHF modulator. It really was a hack but it worked well. Regards, John