Re: The 20s is apparently faster than the 32sii (but not the 32s) Message #2 Posted by Karl Schneider on 3 Jan 2010, 4:22 a.m., in response to message #1 by Dave Britten
Dave 
My HP32S (1990 model with recessed display) takes 56 seconds to obtain all four factors.
Since it lacks the "<=" and ">=" tests, a small workaround was necessary:
32SII: 32S:
Z24 x<=y? Z24 x>y?
Z25 GTO Z Z25 GTO V
Z26 RCL X Z26 GTO Z
Z27 STO F V01 LBL V
Z28 XEQ X V02 RCL X
Z29 CLx V03 STO F
Z30 RTN V04 XEQ X
V05 CLx
V06 RTN
Here are my checksums on the HP32S, which are not the same as those on the HP32SII for the same instructions:
LBL F 714D 10.5
LBL Y 0116 19.5
LBL Z E93C 39.0
LBL V 721A 9.0
LBL W 63E1 15.0
LBL X 5878 15.0
Between two models having the same microprocessor, why does the moreadvanced one tend to run somewhat slower? For example, it has also been claimed that the HP11C is marginally faster than the HP15C. I speculate that the lengthier microcode of the moreadvanced models causes machinelevel instructions to take a bit longer to be found from opcodes. However, moreknowledgeable folks might have a better answer.
Addendum:
Thinking about this a bit more, I'd assume that the ROM contents include some kind of index  an address lookup table that points to where the instructions for a given opcode reside in ROM. That would speed things up, but access is probably still a bit slowed by larger ROM contents.
Another factor is overloading of operations. Consider the HP11C versus the HP15C:
On the HP11C, "*" only multiplies two realvalued scalars.
On the HP15C, "*" can multiply two realvalued scalars, two complexvalued scalars, two matrices, or a real scalar and a matrix. Under the microcode for "*" (hex opcode FC), conditional tests for the types of both arguments and status of flag 8 must be performed before the multiplication is done.
Regarding the HP32S and HP32SII, the display and memory management are almost the same. The difference in functionality is mostly the HP32SII's equations and fractions  not nearly as substantial as the difference between the HP11C and the HP15C. Thus, the difference in execution time between 7680 seconds (HP32SII) and 56 seconds (HP32S) is surprising to me. I had 207 bytes of other programming in the HP32S at the time of the test, so I can't necessarily credit fast GOTO's.
 KS
Edited: 4 Jan 2010, 1:12 a.m. after one or more responses were posted
