When the Tandy 1000 EX and HX models were produced, they were designed to be lowcost entrylevel DOSbased computers, and therefore, lacked a standard ISA slot, RS232C port, and provisions for a permanent disk storage system (hard drive). RAM expansions were possible up to 640k through the PLUS RAM cards, but the takerate on those was very low and they are nearly impossible to find in 2021. The Rob Krenicki 3in1 board solves all these issues by adding a CF to IDE interface w/ programmable BIOS, an additional 384k of RAM, and an RS232C interface. As of 2/16/2021, there are no preassembled units left, but Rob is still selling the bare boards with a parts list of everything you need from Mouser Electronics to complete the build. With basic soldering skills, anyone can build this board with relative ease. Rob has stated that he has about 30 boards left, which include the custom backplate and two custommade pin headers, but he also mentioned someone else may take over the production. I will update this with links to the finished unit maker if such info is furnished to me. Here's where you can buy the boards:

https://docs.google.com/forms/d/e/1FA...

More info regarding the 3in1 project including necessary build info and files:
https://www.tindie.com/products/rkren...