The Reading Anchor

The problem

Ordinary teleprompters store the scroll position in pixels. That works right up until the text changes.

Insert a paragraph three pages above the reading point and every line below it moves down. Pixel 4,200 used to be "nobody has to stop the recording"; now it is a sentence from two paragraphs earlier. The presenter sees the text jump.

The same happens when you raise the type size, change the margin, or switch to a wider typeface. Nothing about the content changed — only the layout — but the position was stored in the layout's units, so the position broke.

That is why those apps make you leave the presentation screen to edit. It isn't a missing feature; it's the way they hold the position.

The fix

Valendo stores the position as a place in the text, not on the screen: a block, and a word inside it. Block 7, word 34. Nothing about pixels, nothing about lines.

After any change to the layout, the pixel is worked out again from that place. Insert paragraphs above it and wordundefinedis still wordundefined— it just sits lower on a taller line. The presenter sees nothing move.

What it gives you

• Rewrite a sentence with the show on the air.
• Raise the type size because the presenter squinted, mid-sentence.
• Insert a whole block the producer just handed you, above where the reading is.
• Change the margin, the alignment, the number of words per line.

None of these move the word being read.

Two more things come with it, for free:

• The presenter's screen and your preview never drift apart. Both work out where the reading is from the same few numbers — the pace, where it started, and when — so there is no stream of positions to fall behind. Your preview is the presenter's screen at its real resolution, not an approximation of it.
• Changing the type size only changes the height of a line, never which words share it. The look can change under a running show and the read stays put.