Jim Elliott wrote: > There was a very expensive option to > upgrade the 155 to a 155-II and the 165 to a 165-II which > basically added DAT. Very few customers took up this option as > the more attractive ($) option were the S/370 158 and S/370 168 > which had DAT and VS built-in.
Unless you had recently purchased the 165... :-( The change from a 165 to a 165-II was about as close as you can get to a forklift upgrade while still calling it an upgrade. There were entire replacement frames rolled in for the CPU, and similar ones for the (standalone) channels, to add IDA. It took almost a week. Once upgraded, the 165-II ran almost like a 168, except of course that it was expecting to talk to 2uS core memory. But if you put OEM solid-state memory on it, it turned out to be one of the many cases (not just IBM, of course) where the hardware people had put in a little delay circuit to wait for the slow core, and the OEM figured out that just removing one card would take out the delay, and talk at the full speed of the storage. Tony H.
