HP-65 Question

[Greg]

The HP-65 only supports one layer of subroutines. You can call one from a main program but you shouldn't call another from there.

The HP-65 Owners Manual says, if you do call lower level subroutines, the first RTN will take you back to the main program.

That suggests that starting with 0.00 in X and pressing [D] in the following:

PHP Code:

001: 23 : LBL
002: 11 : A
003: 01 : 1
004: 61 : +
005: 24 : RTN
006: 23 : LBL
007: 12 : B
008: 02 : 2
009: 61 : +
010: 11 : A
011: 03 : 3
012: 61 : +
013: 24 : RTN
014: 23 : LBL
015: 13 : C
016: 04 : 4
017: 61 : +
018: 12 : B
019: 05 : 5
020: 61 : +
021: 24 : RTN
022: 23 : LBL
023: 14 : D
024: 06 : 6
025: 61 : +
026: 13 : C
027: 07 : 7
028: 61 : +
029: 24 : RTN 


will produce (6 + 4 + 2 + 1 + 7 +) 20.

Does anyone have a physical HP-65 that can confirm that for me?

[Brad Barton]

(03-31-2017 08:16 PM)Greg Wrote:  will produce (6 + 4 + 2 + 1 + 7 +) 20.

Does anyone have a physical HP-65 that can confirm that for me?

Yes, the result is 20 on a physical 65. As you suspected, when the program encountered the RTN in the A subroutine, it was sent back to finish up the originally executed D subroutine, rather than run sequentially through the other subs.

Brad

[teenix]

(03-31-2017 10:47 PM)Brad Barton Wrote:  

(03-31-2017 08:16 PM)Greg Wrote:  will produce (6 + 4 + 2 + 1 + 7 +) 20.

Does anyone have a physical HP-65 that can confirm that for me?

Yes, the result is 20 on a physical 65. As you suspected, when the program encountered the RTN in the A subroutine, it was sent back to finish up the originally executed D subroutine, rather than run sequentially through the other subs.

Brad

Oops, I missed that point in the 65 manual.

I rewrote the 65 emulator's Mark and Search code to manage the subroutines in the same way. The emulator now returns 20 as well.

cheers

Tony

[Greg]

Wow that was fast Tony. I haven't even put up the fix I developed for mine yet, as I wanted to confirm the behaviour on the real thing first.

I'd noticed the problem on other emulators too. Yours always looks so good.

[teenix]

(04-01-2017 12:59 AM)Greg Wrote:  Wow that was fast Tony. I haven't even put up the fix I developed for mine yet, as I wanted to confirm the behaviour on the real thing first.

I'd noticed the problem on other emulators too. Yours always looks so good.

Hi Greg,

Thanks

It's been awhile since I got the 65 working so it was a bit of a brain strain remembering how the code for the program buffer worked :-)

Just now, I had to upload again because I forgot to update the PICmicro code for the 65 hardware emulator as well.

Cheers

Tony

[Brad Barton]

Amazing response! Thanks for updating the app so quickly.

Brad