Multi (i) register techniques help, please.

[Dieter]

(06-03-2018 06:15 PM)Csaba Tizedes Wrote:  Hi, I found something from the past: nested loops with one index register for HP-15C (I have not checked I am sure it can be optimize, but maybe it give some idea for somebody):

I'm not sure if I get your point here, so let me ask:

- As far as I can see this method does not handle multiple index registers for cases where data registers have to be stored or recalled, i.e. something like RCL IND 03 and RCL IND 04 on an HP-41.

- However, the example handles multiple loop counters. But... the 15C does not restrict DSE and ISG to the I-register (as the HP67, 34C and others do). Unlike these it directly supports ISG and DSE for any register, e.g. ISG 3 or DSE ,4.

So I'd like to ask where the benefit of the proposed method is.

Dieter