Wow what a cool site.
Currently resoring a ZX81, and search engines brought me here.
Was blowen away to learn about Gaming Keynboards having mehnical swiches. Got one for $15 new, has single sided pcb, bit of drenal work, and solder links for new matrix. Also using a 512K NVSRam chip for the 16K upgrade. Will still be 16K. Goto use whats on hand. Just gota get the composite video back puch thing working.
Awsome site, loved seeing all the old machines, i will be back