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(41CX w/Advantage Pac) Feet inches fractions
06-22-2022, 09:35 PM (This post was last modified: 06-28-2022 01:51 AM by DMaier.)
Post: #1
(41CX w/Advantage Pac) Feet inches fractions
This code takes decimal inches, e.g., 14.25 in X and returns the following in Alpha:
  • feet inches-fractions if flag 1 is clear, e.g., 1' 2-1/4"
  • inches-fractions if flag 1 is set, e.g., 14-1/4"
The intended application is formatting inches for display or printing after performing decimal calculations. It uses XTOA to get the ' and " characters as well as AIP from the Advantage PAC.

Note: There's an old forum topic HP-41 Advantage Pac AIP function, anyone? that provides alternatives if AIP isn't available. In particular, Namir provides an equivalent to AIP for the CX.

The maximum denominator, which should be a power of 2, is assumed to be set in register 0. Note that the code rounds to the nearest fraction.

The code modifies flag 2 and registers 2 and 3.

Sample output (Reg 1=8, flag 1 clear):

Code:

12.0000     1'
12.4900     1' 1/2"
 1.0000     1"
 1.2500     1-1/4"
14.0000     1' 2"
14.0626     1' 2-1/8"
14.3125     1' 2-3/8"
 4.0010     4"
 7.9990     8"

Code:

LBL "FIF"
CLA
CF 02
X<=0?
"-"
ABS
RCL 00
*
.5
+
INT
RCL 00
/
ENTER
FS? 01
GTO 00
INT
X=0?
GTO 01
12
/
INT
X=0?
GTO 01
AIP
39
XTOA
RDN
ᵀ" "
LBL 01
RDN
ENTER
ENTER
12
MOD
LBL 00
INT
X=0?
GTO 02
SF 02
AIP
LBL 02
RDN
FRC
X=0?
GTO 05
FS? 02
ᵀ"-"
SF 02
RCL 00
*
STO 01
RCL 00
STO 02
LBL 03
RCL 01
2
MOD
X>0?
GTO 04
2
ST/ 01
ST/ 02
GTO 03
LBL 04
RCL 01
AIP
ᵀ"/"
RCL 02
AIP
LBL 05
34
FS? 02
XTOA
AVIEW
END

EDIT: Based on comments from Xorand and Thomas Klemm, below, fixed the description to refer to the correct register and removed a couple of unnecessary bytes.
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06-27-2022, 01:25 AM
Post: #2
RE: (41CX w/Advantage Pac) Feet inches fractions
What should be in register 00? The code starts out by recalling 00 and multiplying it by x, adding 0.5, then dividing by register 00. By default, my register 00 was equal to zero, so I immediately got a data error when dividing.
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06-27-2022, 04:53 AM
Post: #3
RE: (41CX w/Advantage Pac) Feet inches fractions
(06-22-2022 09:35 PM)DMaier Wrote:  The maximum denominator, which should be a power of 2, is assumed to be set in register 1. Note that the code rounds to the nearest fraction.

Based on the code that should be register 00 instead.
The sample output uses 8, but you could also use 16.
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06-27-2022, 04:39 PM (This post was last modified: 06-27-2022 04:56 PM by Xorand.)
Post: #4
RE: (41CX w/Advantage Pac) Feet inches fractions
Ah, ok, that makes more sense. Will give it another try.

Edited to add: Yes, that worked. Thanks!
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06-27-2022, 06:40 PM
Post: #5
RE: (41CX w/Advantage Pac) Feet inches fractions
Nice to see it's working for you now.

(06-27-2022 01:25 AM)Xorand Wrote:  The code starts out by recalling 00 and multiplying it by x, adding 0.5, then dividing by register 00.

You missed taking the integral part with INT:
Code:
RCL 00
*
0.5
+
INT
RCL 00
/

This multiplies the number by the maximum denominator and rounds it to the nearest integer.
It makes sure we end up with nice fractions.

Later on the fraction is reduced if possible:
Code:
RCL 00
*
STO 01
RCL 00
STO 02
LBL 03
RCL 01
2
MOD
X>0?
GTO 04
2
ST/ 01
ST/ 02
GTO 03
LBL 04

We could use just .5 instead of 0.5 to save a precious byte and omit the redundant RTN statement at the END to save another one.
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06-27-2022, 11:01 PM (This post was last modified: 06-27-2022 11:02 PM by Xorand.)
Post: #6
RE: (41CX w/Advantage Pac) Feet inches fractions
(06-27-2022 06:40 PM)Thomas Klemm Wrote:  Nice to see it's working for you now.

You missed taking the integral part with INT:

I was paraphrasing, but yes, I saw that.

True on the .5 and RTN. I've got it saved off to card now. Smile
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