Interak video card upgrade.

161105-img_20161105_145915When I received the Interak-1 it had two video cards. One (VDU-K) was finished and working. The other had all of the passive components fitted – resistors, capacitors etc – but the semiconductors had not been added.

I wasn’t sure why there was the second card at first as they both looked the same but on closer inspection the second is a VDU-2K and at the back of one of my manuals is a preliminary description of the card. I think it was pre-release when the previous owner got it as the documentation isn’t as thorough as the other manuals but it appears that this card is 64 characters wide rather than the 32 characters of the VDU-K.

I went through the parts list and bought the missing ICs, fitted them are here we are.

There are a couple of problems. Firstly, in 64 column mode, the line input is half way up the screen. Secondly, whatever is typed in on the keyboard is misunderstood and a “>” character is printed.

The first problem could be just the the ROMS don’t know how to drive the new card and that I need new ROMS.

The second problem is more interesting. I don’t know yet why the video card is affecting the keyboard input, I have a keyboard input card in a separate slot so it’s all a bit odd.

More news to follow.

2 thoughts on “Interak video card upgrade.”

  1. Do you have the twenty pages or so that are entitled “USER NOTES ON VDU-2K ISSUE 8509 29TH SEPTEMBER 1987”?

    If not, let me know.

    1. Thank you for your comment David,

      No, I don’t have the user notes you mentioned.
      Thanks for the offer.
      That will be a great help.

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