RCL Σ+

02072020, 01:37 PM
(This post was last modified: 02112020 01:28 PM by Dave Britten.)
Post: #1




RCL Σ+
Somehow I've gone all this time without realizing that RCL Σ+ can be used to recall ΣX and ΣY to X and Y on quite a few models. Which models support this? I've only had a chance to check a few so far.
45: I think this was a yes, I'll have to double check 80: No (no stat regs, only very basic onevariable summations that work entirely on the stack) 65: No (no built in stat functions; what about the 67 which has them?) 25: Haven't tested yet, ROM was really packed to the brim so it might have been left out 38E/C: No 41C: No (Σ+ is a shortcut for 01 with STO/RCL/GTO/XEQ) 12C: No 15C: Yes 16C: No (no summation/stat functions) 27S: No (listbased stats, not RPN, no Σ+ key) 32S, 32SII: No (Σ+ becomes the F key for STO/RCL/GTO/XEQ) 42S: No (Σ+ becomes a menu key for the variable menu when STO/RCL is active, and TOP.FCN can't be used to get to Σ+ while STO/RCL are pending); SUM function does the same thing but overwrites X and Y without lifting the stack Do any support STO Σ+ to store two values directly into the ΣX and ΣY registers? 

02072020, 04:45 PM
(This post was last modified: 02072020 05:32 PM by Thomas Okken.)
Post: #2




RE: RCL Σ+
(02072020 01:37 PM)Dave Britten Wrote: Somehow I've gone all this time without realizing that RCL Σ+ can be used to recall ΣX and ΣY to X and Y on quite a few models. Which models support this? 25/25C: No 19C/29C: Yes 67/97: Yes 41C: No (With card reader: Yes, 7RCLΣ) 42S: Yes (SUM) (02072020 01:37 PM)Dave Britten Wrote: Do any support STO Σ+ to store two values directly into the ΣX and ΣY registers? Not as far as I know, but I'm prepared to be surprised. 

02072020, 11:01 PM
Post: #3




RE: RCL Σ+
(02072020 01:37 PM)Dave Britten Wrote: Somehow I've gone all this time without realizing that RCL Σ+ can be used to recall ΣX and ΣY to X and Y on quite a few models. Which models support this? I've only had a chance to check a few so far. Yes, the 45 does. cheers Tony 

02072020, 11:17 PM
Post: #4




RE: RCL Σ+
What about 35s ? I gave mine to my son...


02082020, 12:05 AM
Post: #5




RE: RCL Σ+
Bob Prosperi 

02092020, 04:48 PM
Post: #6




RE: RCL Σ+
33E and 11C support this. I used it regularly, because it saves a program line when you want to recall 2 memories.
Sto Σ+ doesn't work. Neither do Sto π and Rcl π. I tried. HP 33E, HP 11C, HP 48 SX, HP 35S 

02102020, 07:47 AM
Post: #7




RE: RCL Σ+
Hi Dave.
When I use the RCL Σ+ on my 12C, it does not recall the ΣX and ΣY. It simply performs Σ+. Does your 12C actually perform the RCL Σ+ function? Or is it an error? Best,  Carsen 

02102020, 08:14 AM
Post: #8




RE: RCL Σ+
(02102020 07:47 AM)Carsen Wrote: Hi Dave. It is probably not supported and the [RCL] is cancelled when you press the [Σ+]. cheers Tony 

02102020, 08:48 AM
Post: #9




RE: RCL Σ+
According to the op code tables here, RCL Σ+ is supported on:


02102020, 02:49 PM
Post: #10




RE: RCL Σ+
I could have sworn it worked on my 12C, but I could be imagining things. I do have quite a few Voyagers accumulating these days...


02102020, 03:49 PM
Post: #11




RE: RCL Σ+
Strangely, RCL Σ+ doesn't push its values onto the stack the same way on all models. Some directly overwrite X and Y, leaving the previous values of Z and T in place (e.g. the HP55, 67, and 29), while others first lift the previous values of X and Y into Z and T (e.g. the HP45, 33E and 34C).
Did RCL Σ+ disable stack lift on any models? That would seem like a crazy thing to do, but I seem to recall that some model did so, which tells me that it must be true, because "The curse of aging is a sort of creeping infallibility." <0ɸ0> Joe 

02102020, 08:29 PM
Post: #12




RE: RCL Σ+
(02102020 03:49 PM)Joe Horn Wrote: Strangely, RCL Σ+ doesn't push its values onto the stack the same way on all models. Some directly overwrite X and Y, leaving the previous values of Z and T in place (e.g. the HP55, 67, and 29), while others first lift the previous values of X and Y into Z and T (e.g. the HP45, 33E and 34C). On the machines I'm familiar with, RCL Σ+ (a.k.a. SUM on the HP42S) overwrite X and Y and don't lift the stack. I think the idea was to match the behavior of MEAN and SDEV. 

02112020, 03:53 AM
Post: #13




RE: RCL Σ+
10C: No


02112020, 04:22 AM
(This post was last modified: 02112020 04:27 AM by Gamo.)
Post: #14




RE: RCL Σ+
Example of the use of [∑+] for the HP12C
Combination 01 ∑+ // Input Value to X and Y stack 02 RCL 2 // ∑x 03 X=0 04 GTO 12 05 ÷ 06 STOx1 // n 07 1 08 STO4 // ∑y 09 STO2 // ∑x 10 RCL 4 // ∑y 11 GTO 02 12 RLC 1 // n Remark: It simply performs Σ+ Gamo 

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