Should returned an ordered list of Altera issued patents, from the first one onward. If it doesn't work, then go to this web page:
Type this in as the search:
inassignee:Altera inassignee:Corporation
and use the options on the left hand column to do: Sort by date (old first).
Likewise for Actel,
Or else do this search manually:
inassignee:Actel inassignee:Corporation
If you look on the first page for the patents with Abbas El Gamal as first inventor, you'll find the ones that cover the famous fuse-programming algorithm.
Finally, Lattice's early patents included some important ones too:
Or manually:
inassignee:Lattice inassignee:Semiconductor inassignee:Corporation