Integral in solve on HP 42S?

[Thomas Okken]

(02-26-2019 03:15 AM)lrdheat Wrote:  I will begin to try-relearn indirect addressing (last did this on an HP 67 in the 1970's

You're in for a treat, then! I have no experience with the HP-67 myself (I own one now, purchased on eBay, but couldn't have afforded it back when it was new), but I do have experience with the HP-19C, which is very similar. Both have only one "indirect" register, which makes a lot of algorithms awkward to implement, always having to shuffle things around to get the right pointer into register 0 (which is the I equivalent on the 19C and 29C).

Compared to that, programming the 41C, where every register, even the stack registers, can be used for indirect addressing, is so much more pleasant, and the 42S inherited that programming model.