Silver SK-311 knitting machine first appeared on the market in the later 1960s. It might be the first machine capable of reading punchcards for automatic needle selection and patterning.

In fact it is the first model (and so far as I’ve seen, the only) with the “card-matic” words in the name. Silver SK311 takes punchcards with 24 holes. The plastic pins on the card-reader mechanism are pressed, which then transfer the pattern or pressed and unpressed states to the patterning drums, which then guide the needles either into a standard or patterning position.

Note that this model still has only one lever on the pattern panel (a lever with a red cap below): only to release the punchcard so it advances when the machine knits patterns and is passed back and forth. Later models have two levers: one for card release and one to expand the pattern vertically by a factor of two. 

It still has several vintage features inherited from its earlier sisters, like a stand-alone toolbox and a somewhat boxy feel/shape (the carriage, the handle, the endcaps, etc.).

This machine has an interesting feature: when you knit for a while, and the pattern on the card is finished, a STOP word will appear on the display of the punchcard reader.

Then you will have to rewind the card to the starting position. The manual describes this feature well. I am not sure if this is the feature of the cards themselves or of the reader. I am yet to work on one of those machines.

Later knitting machines allow a constant reading of the card: the card is simply clipped and is ready circular over and over.

A distinct feature of Silver SK311 (not seen in similar later models, like Silver SK312 and Silver SK313) are buttons on the carriage. I am currently looking for a manual describing what these buttons are.