On Thu, Jan 6, 2022, 08:45 Mike Katz via cctalk <cctalk at classiccmp.org> wrote: > There was also a 1K by 4 version of this tube. > I've never seen any info on a 1K*4 Selectron, but they weren't even able to make the 4K*1 work, and the only production tubes were 256*1.