We were working in collaboration, details in the 6 page forum Pitou
started including two working designs.
I did several through-hold boards, probed them and A1 board to solve the
Cycle Steal mystery, then posted the KiCad files.
Please see:
https://forum.vcfed.org/index.php?threads/ibm-5110-ram-timings.1253087/post…
for a photo of the through-hole board & parts that both Pitou and I
tested in 5110 machines.
I just added a photo of the kit showing the board & parts needed, easy
assembly.
Robert
On 9/22/25 2:08 AM, Christian Corti via cctalk wrote:
  On Fri, 19 Sep 2025, Steve Lewis wrote:
  Well, just yesterday I tested a set of RWS (RAM)
replacement cards
 for the
 IBM 5110 from Patrick Lebbard from Canada - and I'm very impressed. 
 They
 work well, I had them running for a few hours.
 Details are described here:
 
https://voidstar.blog/ibm-5110-rws-ram-modern-make-replacements/
 or VCF thread
 
https://forum.vcfed.org/index.php?threads/ibm-5110-ram-timings.1253087/ 
 Interesting, I was thinking about replacing the RWS modules with two
 standard 62256 SRAMs (plus 74180) for my systems that aren't maxed out.
 But I would not consider any SMD stuff.
 Christian