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HP12C: date functions and flashing display ?!
01-25-2018, 07:14 PM
Post: #1
HP12C: date functions and flashing display ?!
First of all: I do not have a real 12C, instead I am using HP's own emulator which I think is supposed to behave like the real thing.
And here I noticed something that I cannot explain (yet):

In some cases the date functions (ΔDYS and DATE) return the result with a flashing display if the function is executed in a program (!).

Example:

1,011900 [ENTER] 1,012000 g[ΔDYS] => 36524


Fine. Now do the same thing within a program.
Clear program memory, then enter ΔDYS as step 01.

f[P/R] f[PRGM] g[ΔDYS] f[P/R]

1,011900 [ENTER] 1,012000 [SST] => 36524 flashing

Is this the same on a real 12C or a quirk in the emulator?
If this is by design: what causes the display to flash?

Dieter
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01-25-2018, 08:05 PM (This post was last modified: 01-26-2018 03:03 AM by Don Shepherd.)
Post: #2
RE: HP12C: date functions and flashing display ?!
(01-25-2018 07:14 PM)Dieter Wrote:  Is this the same on a real 12C or a quirk in the emulator?

Neither my old 12c (2001 with 1 batt) nor the 12c+ (2008 I think, 2 batts) exhibit this flashing behavior.
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01-25-2018, 10:03 PM (This post was last modified: 01-25-2018 10:07 PM by TheKaneB.)
Post: #3
RE: HP12C: date functions and flashing display ?!
My first generation made in USA (3 LR44 batteries, 27th week 1984) do not flash.
Given the tests, I assume it's a bug in the emulator. Maybe the flashing "running" display causes the end result to flash also, for some reason?

Software Failure: Guru Meditation

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Antonio
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01-25-2018, 10:53 PM
Post: #4
RE: HP12C: date functions and flashing display ?!
My modern HP-12C does exhibit this behavior. It flashes when only used in the program. It was bought back in late 2016.
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01-26-2018, 01:07 AM
Post: #5
RE: HP12C: date functions and flashing display ?!
Yes I try on both the HP own Emulator on PC and 12C+ gave result with flashing answer.

According to the HP-12C Owner's Handbook on the topic about Number of Days Between Dates state that

"When [DATE] is executed as an instruction in a running program, the calculator pauses for about 1 second to display the result, then resumes program execution."

So I guess when running DATE in a program it PAUSE one second then going in to a loop cycle that cause the flashing I'm not sure if this is the reason.

Gamo
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01-26-2018, 02:03 AM
Post: #6
RE: HP12C: date functions and flashing display ?!
I tried this on an early 12C+, (s/n 4CY147099S, w/2xCR2032) and it does NOT flash when activated in a program via SST as Dieter suggested. The s/n confirms this is the initial 12C+ design; the latter 12C+ design (with new CPU) was introduced about April '15, so Carsen's is almost certainly this latter version.

To summarize:

12C+ V1 (2008-2015): No Flash
12C+ V2 (2015+): Flashes

@Dieter - what vintage is the 12C emulator you are using?

--Bob Prosperi
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01-26-2018, 07:54 AM
Post: #7
RE: HP12C: date functions and flashing display ?!
(01-26-2018 02:03 AM)rprosperi Wrote:  12C+ V1 (2008-2015): No Flash
12C+ V2 (2015+): Flashes

@Dieter - what vintage is the 12C emulator you are using?

The emulator says "Version 2012 11 29 Rev. 19022".

Dieter
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01-26-2018, 07:57 AM
Post: #8
RE: HP12C: date functions and flashing display ?!
(01-26-2018 01:07 AM)Gamo Wrote:  "When [DATE] is executed as an instruction in a running program, the calculator pauses for about 1 second to display the result, then resumes program execution."

That's the DATE command.
But the example refers to ΔDYS.

Dieter
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01-26-2018, 09:44 AM
Post: #9
RE: HP12C: date functions and flashing display ?!
I don't have an HP-12C to hand right now (no batteries in it) but I do have a SwissMicros DM12L, which runs the original HP-12C's ROM in an emulator.

No flashing.
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