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HP Forum Archive 16

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HP12C Prestige
Message #1 Posted by Vieira, L. C. (Brazil) on 15 May 2006, 1:03 p.m.

Hi, all;

I got myself an HP12C Prestige (a gift) and I am taking some pictures of it to post later. It is mainly an HP12C Platinum of the last series, the one with parenthesis, back-space, undo and LCD contrast plus 80-entries cash-flow analysis (something I'd like to talk about: how/where in the h... are these entries stored?). The HP12C Prestige has all of these.

The color scheme is simply using the LCD frame golden aluminun in both the LCD frame and the keyboard faceplate, like it is done with the Platinum series (instead of aluminun, think of brass, brushed golden). As Gerson mentioned about it earlier, the golden faceplate makes it a little hard to read the orange (gold?) inscriptions for the [f] functions. All the rest seems to be the same.

The protective cover is new. The design follows the one found in the newer HP17BII+ and the HP49G+, with an openning border, but the front and back protective faces are joined with four bands of some sort of elastic tissue, two in the botton and one in each side. The four edges of the calculator´s case remain exposed... but it is fancy, somehow appealing.

When you see the pictures you´ll have a better idea (must read some more and use other words to better describe stuffs in English...)

Keyboard feeling and general operation seem to follow the new HP12C PLatinum series.

Cheers.

Luiz (Brazil)

Edited: 15 May 2006, 1:05 p.m.

      
HP12C Prestige: pictures
Message #2 Posted by Vieira, Luiz C. (Brazil) on 16 May 2006, 12:43 a.m.,
in response to message #1 by Vieira, L. C. (Brazil)

Hi, all;

After further comparison, Prestige's golden surface is a bit darker, more like bronze, as you can see here.

Click to enlarge

Click to enlarge

Click to enlarge

Cheers.

Luiz (Brazil)

            
Re: HP12C Prestige: pictures
Message #3 Posted by tony(nz) on 16 May 2006, 12:52 a.m.,
in response to message #2 by Vieira, Luiz C. (Brazil)

Thanks Luiz - I've never seen a case like that before. Nice photo!

                  
Re: HP12C Prestige: pictures
Message #4 Posted by Vieira, Luiz C. (Brazil) on 16 May 2006, 2:36 a.m.,
in response to message #3 by tony(nz)

Hey, Tony; you're welcome!

Your name, Gene's and Jordi's are mentioned in the HP12C Prestige Owner's Handbook (in fact, 'Manual do Usuário'; seems to be in Portuguese, only) as contributors to the later HP12C Platinum Owner's Manual. Congratulations to you all!

There is one thing I could not understand. I read taht the HP12C Platinum can hold up to 80 cash flows, being [FV] register the holster for the last one (81st). Simple math: 80×7 = 560 bytes (???!!!??) The HP12C Platinum handles up to 399 program steps (bytes?) plus the seven lower numbered registers, R0 to R6. Even if we count the lower numbered registers, there is only a maximum of 64 registes (399÷7 = 57; 57+7 = 64). Where in the h... are these other 16 cash-flow registers hidden? Any idea? If we do the opposite math:

80-7 = 73
399÷73 = 5.465... Nonsense!
I made the following test after clearing all memory ([ON]/[-]):
78  [n]
500 [g][CFj]
100 [g][CFj]
200 [g][CFj]  Error 6
as expected. Then:
    [RCL][g][CFj]
    [RCL][g][CFj]
and the display showed
[ 500.00   ]
Then I did the following:
[RCL][FV]
and the display showed:
[ 100.00   ]
So far so good. At this point I set program mode and added a couple of lines such the program memory now uses two registers, i.e., [g][MEM] returns
[ P-022 r-20 ]
Then I repeat all of the operations above and... nothing changes! As if the cash-flow registers are stored somewhere else. I read at the inside back cover that it is necessary to use program memory up to step #239 prior to actually convert cash flow registers from 80 to 57 into program steps. I did not figure out what did they actually do with teh HP12C Prestige memory. I am going to check if happens the same with the later HP12C Platinum. Any info about this, Tony? Guys? I'd like to know more.

Thanks a lot.

Luiz (Brazil)

                        
Re: HP12C Prestige/ Platinum: # of registers
Message #5 Posted by Marcus von Cube, Germany on 16 May 2006, 11:00 a.m.,
in response to message #4 by Vieira, Luiz C. (Brazil)

Hi Luiz,

I did some experiements with my 12C platinum and I found out that the highest cashflow that can be entered while the program area is full (just 399 R/S) is CF57. The boundary where the stealing of registers for program steps starts is beyond 239 steps. (I figured that out by trial and error and only later I found the info on the very last page of the fine manual.) Now let me do the math:

Internal registers (Stack, LastX): 5
Financial registers (n .. FV):     5
Cashflow and general registers:   81  (including CF0)
Fixed program steps:               1+ (8 steps)  
Variable program steps:           33  ((239 - 8)/7)
                                 ---
Number of registers (total):     125
Each of the cashflow registers occupies 7+1 bytes because the count Nj needs to be taken care of, too. Now let's do the same calculation as above with bytes instead of registers:
Internal registers (Stack, LastX): 35 (5 x 7)
Financial registers (n .. FV):     35 (5 x 7)
Cashflow and general registers:   567 (81 x 7)
Cashflow counts:                   81 (81 x 1)
Program steps:                    239
                                 ----
Number of bytes (total):          957  
It looks like the machine has access to 1 KB RAM and some working memory is set aside for running calculations (the IRR solver solver certainly needs them).

The original 12C has less memory to work with and the MEM output is of more help then on the 12Cp because it shows quickly, how program memory steals from the general (and cashflow) registers. With full program memory (100 steps) only 7 registers remain. Let's do the same as above with all memory devoted to registers:

                                  regs   bytes
Internal registers (Stack, LastX):  5     35 (5 x 7)
Financial registers (n .. FV):      5     35 (5 x 7)
Cashflow and general registers:    20    140 (20 x 7)
Cashflow counts:                    3(?)  20 (20 x 1)
Program steps:                      1+     8 
                                  ---   ----
Total number of registers/bytes:   34    238  
I don't know the total amount because I don't know how may registers are needed for the solver functions to work.

The funny thing is, that both machines convert program steps in chunks of 7 per register but the count must still be stored somewhere. My assumption is that, on a classic 12C, these counts are stored in 3 extra registers, giving a total of 21 bytes. The 21st byte is probably used for the first byte of program memory. Eric knows certainly more.

Marcus

Editied to redo the calculations on the base of 7 bytes/register.
Edited to correct the number of cashflows on the 12Cp.

Edited: 16 May 2006, 12:50 p.m.

                              
Re: HP12C Prestige/ Platinum: # of registers
Message #6 Posted by Eric Smith on 16 May 2006, 2:49 p.m.,
in response to message #5 by Marcus von Cube, Germany

I haven't studied the memory usage of the original 12C in depth, but all the original Voyagers actually have 40 registers total, except the 15C which has 82.

The "R2D2" chip (RAM/ROM/Display Driver) has 40 registers in two groups of 8 and 32 registers. The group of 8 contains the stack, Last X, and various internal housekeeping information (similar to the HP-41C "status" registers). The group of 32 is mostly used for "user" memory (registers, program, etc.), though a few of the registers are used for further housekeeping.

The 15C has two R2D2 chips, but the display driver is not used in the second, so the bit-mapped display registers of the second chip are available for use as additional housekeeping registers.

                  
Re: HP12C Prestige: pictures
Message #7 Posted by Vieira, Luiz C. (Brazil) on 16 May 2006, 2:42 a.m.,
in response to message #3 by tony(nz)

Hey, Tony; you're welcome!

Your name, Gene's and Jordi's are mentioned in the HP12C Prestige Owner's Handbook (in fact, 'Manual do Usuário'; seems to be in Portuguese, only) as contributors to the later HP12C Platinum Owner's Manual. Congratulations to you all!

I forgot to mention: the upper border of the case is held against the front face by two square magnets. And the back of the protective case has a belt support... Check it out.

Click to enlarge

There is one thing I could not understand. I read that the HP12C Prestige, like the later HP12C Platinum, can hold up to 80 cash flows, being [FV] register the holster for the last one (81st). Simple math: 80×7 = 560 bytes (???!!!??) The HP12C Platinum handles up to 399 program steps (bytes?) plus the seven lower numbered registers, R0 to R6. Even if we count the lower numbered registers, there is only a maximum of 64 registes (399÷7 = 57; 57+7 = 64). Where in the h... are these other 16 cash-flow registers hidden? Any idea? If we do the opposite math:

80-7 = 73
399÷73 = 5.465... Nonsense!
I made the following test after clearing all memory ([ON]/[-]):
78  [n]
500 [g][CFj]
100 [g][CFj]
200 [g][CFj]  Error 6
as expected. Then:
    [RCL][g][CFj]
    [RCL][g][CFj]
and the display showed
[ 500.00   ]
Then I did the following:
[RCL][FV]
and the display showed:
[ 100.00   ]
So far so good. At this point I set program mode and added a couple of lines such the program memory now uses two registers, i.e., [g][MEM] returns
[ P-022 r-20 ]
Then I repeat all of the operations above and... nothing changes! As if the upper cash-flow registers are stored somewhere else. I read at the inside back cover of the HP12C Prestige Owner's Manual that it is necessary to use program memory up to step #239 prior to actually convert cash flow registers from 80 to 57 into program steps. I did not figure out what did they actually do with the HP12C Prestige memory. I am going to check if happens the same with the later HP12C Platinum. Any info about this, Tony? Guys? I'd like to know more.

Thanks a lot.

Luiz (Brazil)

Edited: 16 May 2006, 2:56 a.m.

                  
Re: HP12C Prestige: pictures
Message #8 Posted by Walter B on 16 May 2006, 3:31 p.m.,
in response to message #3 by tony(nz)

Such cases are used for PDAs and mobile phones.

            
Re: HP12C Prestige: pictures
Message #9 Posted by Hugh Evans on 16 May 2006, 2:56 a.m.,
in response to message #2 by Vieira, Luiz C. (Brazil)

This label contrast issue is getting way out of hand. I'm going to post my heavily researched color scheme to the hp48 newsgroup... Hopefully someone at HP will take notice.

                  
Re: HP12C Prestige: pictures
Message #10 Posted by Gene on 16 May 2006, 8:07 a.m.,
in response to message #9 by Hugh Evans

I believe HP already HAS taken notice, but please post your results. :-)

The most recent color scheme would be that of the 40gs and it is much better than the 12c prestige, etc.

I think HP has starting thinking again with regard to color choice.

                        
Re: HP12C Prestige: pictures
Message #11 Posted by Hugh Evans on 20 May 2006, 5:16 p.m.,
in response to message #10 by Gene

I've put them up on the hp48 newsgroup, and they were well received. It will be interesting to see if they appear on the upcoming hp-50G. Perhaps I'll email my work to Cyrille just to be sure HP takes notice.

The good news about the 50G is that even if it doesn't use a good color scheme my retrofit kit will work with it!

-Hugh


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