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I believe the other series is C.A.D.S. (an acronym for "Computerized Attack/Defense System), by John Sievert (a pseudonym).
"They're called C.A.D.S.- Computerized Attack/Defense System.The next generation of America's high-tech soldier. Seven foot tall battle armor suits that are equipped with flame-throwers, armor piercing shells, machine guns and much more.all operated by voice command. However no one dreamed that they would become America's last line of defense. The unthinkable has happened. The Soviet Union's nuclear first strike has left America crippled, tens of millions dead, and its armed forces decimated. Now the Soviets begin their sweep across the American landscape to achieve complete victory. Only one thing stands in their way: Colonel Dean Sturgis and his C.A.D.S. unit. Now, untested in battle, the C.A.D.S. must race against time to rescue the President from his White House bunker before the Soviet's can capture him and demand the surrender of the United States."
Here's a list of the C.A.D.S. titles:
C.A.D.S. [by Ryder Syvertsen & Jan Stacy] (Zebra 0-8217-1641-7, Nov ’85, $3.50, 398pp, pb) [C.A.D.S.] Sf war novel of the “Computerized Attack/Defense System”. They are the “high-tech soldiers of tomorrow, fighting for America’s survival.”
C.A.D.S. # 2: Tech Battleground [by Ryder Syvertsen] (Zebra 0-8217-1790-1, Apr ’86, $2.95, 285pp, pb) [C.A.D.S.] Sf post-holocaust adventure novel of armored warriors vs. Soviet invaders, second in the series.
C.A.D.S. # 3: Tech Commando [by Ryder Syvertsen] (Zebra 0-8217-1893-2, Sep ’86 [Aug ’86], $2.95, 252pp, pb) [C.A.D.S.] Post-holocause sf series adventure novel.
C.A.D.S. # 4: Tech Strike Force [by Ryder Syvertsen] (Zebra 0-8217-1993-9, Feb ’87 [Jan ’87], $2.95, 270pp, pb) [C.A.D.S.] Fourth novel in the sf post-holocaust adventure series.
C.A.D.S. # 5: Tech Satan [by Ryder Syvertsen] (Zebra 0-8217-2313-8, Mar ’88 [Feb ’88], $2.95, 286pp, pb) [C.A.D.S.] High-tech post-catastrophe military novel.
C.A.D.S. # 6: Tech Inferno [by Ryder Syvertsen] (Zebra 0-8217-2410-X, Jul ’88, $2.95, 255pp, pb) [C.A.D.S.] Post-holocaust adventure novel. Men in fighting suits battle the evil communists.
C.A.D.S. # 7: Doom Commander [by Ryder Syvertsen] (Zebra 0-8217-2685-4, Jun ’89 [May ’89], $2.95, 220pp, pb) [C.A.D.S.] Post-holocaust military sf novel.
C.A.D.S. # 8: Cybertech Killing Zone [by Ryder Syvertsen] (Zebra 0-8217-2818-0, Oct ’89, $2.95, pb) Post-holocaust military sf novel.
C.A.D.S. # 9: Suicide Attack [by David Alexander] (Zebra 0-8217-2926-8, Mar ’90 [Feb ’90], $2.95, 224pp, pb) [C.A.D.S.] Post-holocaust military sf novel.
C.A.D.S. #10: Recon by Fire [by David Alexander] (Zebra 0-8217-3147-5, Oct ’90 [Sep ’90], $2.95, 222pp, pb) [C.A.D.S.] Post-holocaust military sf novel
C.A.D.S. #11: Death Zone Attack [by David Alexander] (Zebra 0-8217-3374-5, Aug ’91, $3.50, 176pp, pb) [C.A.D.S.] Post-holocaust military sf novel in an ongoing series.
C.A.D.S. #12: Tech Assassins [by David Alexander] (Zebra 0-8217-3600-0, Dec ’91 [Nov ’91], $3.50, 192pp, pb) [C.A.D.S.] Post-holocaust military sf novel in an ongoing series.
Some of the C.A.D.S. books are available used:
http://www.biblio.com/search.php?author=John+Sievert&title=&keyisbn=&format=any&stage=1