HP29C - DSZ ISZ Question

I have never owned an HP29C (nor given the prices on e-bay am I ever likely to own one either) but would like to know if the operation of the DSZ/ISZ instructions on the HP29C/HP19C is similar to the DSE/ISG functions on the HP11C - obviously in the case of the HP29C/HP19C the test is against a zero value, but did the HP29C use the fractional and integer parts of the I register in the same was as the HP11C (and HP34C) or was it was it altogether simpler?


Mike T.


I don't have a 29/19 either, but have used a 29C for a short while many years ago. If I recall correctly (I apologize in advance if I'm wrong), as the test value was zero and as the step was always one, the fractional part is always zero´. For comparison, in the HP41 any register used for ISG/DSE operations has the format: iiiii.fffcc where i is the initial or current value, fff the final value and cc the step.


Small addition: the fractional part doesn't need to be zero. It's just being ignored.


To summarize - the fractional part of the value in R0 is ignored (and left unchanged?) while integer part is incremented/decremented and next instruction is skipped if the result is zero. Please correct me if I'm wrong!

Many thanks for the feedback.

Mike T.


fractional part is indeed left unchanged and of course the test is done on the integer part only.


Thank you...

Possibly Related Threads...
Thread Author Replies Views Last Post
  restoring HP29C - help needed Alberto Fenini 9 1,703 11-25-2012, 07:56 AM
Last Post: Alberto Fenini
  wp 34s: DSE vs. DSZ (poll) Walter B 40 5,872 05-27-2011, 06:02 AM
Last Post: Paul Dale
  HP29C strange behavior Alberto Fenini 14 2,185 02-16-2010, 12:30 AM
Last Post: Eric Smith
  HP29C Question Mike T. 5 1,188 10-17-2007, 01:46 PM
Last Post: Thomas Okken
  HP29C documentation and data Vieira, Luiz C. (Brazil) 10 1,751 08-22-2003, 12:06 AM
Last Post: Vieira, Luiz C. (Brazil)
  Battery pack for HP29C? Steve Inselberg 1 573 05-23-2003, 04:14 PM
Last Post: David Smith
  HP19C & HP29C Howard 2 742 05-22-2003, 04:33 PM
Last Post: David Smith
  HP29C problems Barry 5 1,109 10-11-2002, 11:18 AM
Last Post: John Garza (3665)
  My HP29C gave me a scare. John Ioannidis 1 587 09-05-2002, 03:35 PM
Last Post: David Smith
  previous hp29c thread... john (usa) 0 426 09-12-2000, 07:52 PM
Last Post: john (usa)

Forum Jump: