A good question is, "How best to train with these old chess computers?"
My method is to play a game, do a Stockfish (SF) analysis to find my first poor/weak move, then re-run/set-up the computer to that move and play again with the improvement, rinse and repeat. Eventually you get a very fine and memorable game, in my case this can take 3 or 4 repetitions. I think it's best to set-up the computer strength to be only a few 100 elo rating points above your own. Many of the old chess computers make this whole process quite trivial.
Note, if SF recommends a move/line I would have no hope of playing out I ignore it for a more sensible / human one. Simple fact is at my level, c. 1500, this is good enough giving my likely opponents.
It's a shame that the benefits of these old chess computers appear to be completely ignored nowadays.
one thought on how to use. put the opening on the board to ending variation. then play it. see what the 1800, 2000, computer can do. play it lots of times...so you wont be GM but you will be well versed on 2000 play.
rather than hijack this thread I have re-posted the original question as a new topic.
Appreciate the feedback chessroboto #211 . I am also allergic to 2D screens. On this site I settled for 3D in settings with green and white tournament board - works for me. I found most issues with the 1650 could be resolved by keeping the batteries well charged and turning off the sound - battery hungry. It also involved investing in some rechargeable batteries for those long level 7 epic duels. I can think of no better training technique than attempting to win at each level Black then White respectively. For those a little younger and watching your expenditure such a machine improved me enough to win a John Jaques tournament board and pieces in a newspaper puzzles competition and is still my goto working board .