I was interested to see someone still interested in the Old TI 990/10 & /12 system. I worked for TI from 1980 to 1986 and worked with the 990/10, 990/12 & Business System 1300 & Business System 1500. I started my company in Austin, Texas, building performance products for the TI Systems. We built memory expansion boards, 8 Port CRU Devices compatible with the CI-402, 8 Port & 16 Port Ti-Line devices compatible with the CI-403. We also built "Turbo" upgrades for the 990/10A as well as the fastest memory controller to ever be used with the TI 990/12 and 990/12A. The Memory Controller could be configured as 512K., 1 Meg., 1.5 Meg. and 2 Meg. It was totally Static Ram, ( no hesitating every 14 to 15.5 microseconds for a refresh cycle.) The static ram on our board ran at 35ns and the fastest boards ran at 25ns. ALL CACHE MEMORY. The controllers sold to dealers for $15,000.00 ea. At the request of John Deere, TI supported our 8 Port Terminal Controller under Maintenance Contract. We also used to do fixed price repair on all TI Computer Boards. We also performed Memory Upgrades to the TI 512K. LR Cache controller boards. We could upgrade them to 1 Meg. and 2 Meg. of Dram. The 990/10A was sold as 512K, 1 Meg. and 1.5 Meg. but we could upgrade them to any of those sizes as well as to 2 Meg. We designed over 20 products to work with the TI Systems. I really enjoyed working with them. Nothing since has interested me as much. Sincerely, Marty