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Synthetic Programming
04-27-2015, 03:08 AM
Post: #1
Synthetic Programming
Other than the HP-41 series, has anyone found a way to do synthetic programming on any other HP RPN machine ?

Bob
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04-27-2015, 03:11 AM
Post: #2
RE: Synthetic Programming
The 15c and the 67 and I think the 65.
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04-27-2015, 03:18 AM
Post: #3
RE: Synthetic Programming
(04-27-2015 03:11 AM)Geoff Quickfall Wrote:  The 15c and the 67 and I think the 65.

Geoff,

Do you happen to have an example of synthetic programming on the HP-67 or is there a website I can go to?

Thanks,

Bob
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04-27-2015, 02:15 PM
Post: #4
RE: Synthetic Programming
(04-27-2015 03:18 AM)bshoring Wrote:  
(04-27-2015 03:11 AM)Geoff Quickfall Wrote:  The 15c and the 67 and I think the 65.

Geoff,

Do you happen to have an example of synthetic programming on the HP-67 or is there a website I can go to?

Thanks,

Bob

Bob - search the old and current Forum archives - you will almost certainly find references to the 15C and 67 synthetics - I don't have links handy, but I have seen them both in past spelunking trips into the archives.

--Bob Prosperi
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04-27-2015, 08:58 PM
Post: #5
RE: Synthetic Programming
HP-15C Synthetics
Using the Nonpareil emulator

Kind regards
Thomas
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04-27-2015, 10:27 PM
Post: #6
RE: Synthetic Programming
(04-27-2015 03:18 AM)bshoring Wrote:  
(04-27-2015 03:11 AM)Geoff Quickfall Wrote:  The 15c and the 67 and I think the 65.

Geoff,

Do you happen to have an example of synthetic programming on the HP-67 or is there a website I can go to?

Thanks,

Bob

From 13 years ago:

HP 67 synthetic programming

I remember the Coca-cola commercial cards, but don't have them myself.
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04-28-2015, 03:29 PM
Post: #7
RE: Synthetic Programming
For the HP-65 and -67, there were several tricks, though the term "synthetic programming" only came along with the '41 due to the rich field of options it had in that regard.

One was NNNs: Non-Normalized Numbers. Each digit was represented as binary coded decimal (BCD). The additional values of 10-15 could be used to make text strings are were used on the '67 for "Error" and such (if I recall, the six values of A-F appeared as "rCodE(space)".

Also, if the mantissa was not normalized, i.e. the most significant digit was zero, instructions that did a divide would take longer as they involved multiple subtractions. By creating the proper value, programmable delays or count down / up timers could be created.

Like the '41, the '67 had a larger address and instruction space than was normally used. By getting the program counter out of the normal program space, you could create almost any bit pattern desired and store it on cards - thus the cards mentioned above. This was initially done by deliberately glitching the card reader, later with the use of a "black box" which plugged into the charging port, and later still with a "phase 0 interrupt" button. My poor '67 was subjected to all the above indignities.

The ability to create almost any bit pattern on cards with a '67 led to the exploration of the '41, ultimately resulting in Bill Wickes' remarkable discoveries of Synthetic Programming on that marvelous machine.

On the '65, there was no program or subroutine counter / pointer (!). Instead, programs were stored in a dynamic shift register. Instructions were coded as six bit values. Two such values represented the program counter and the return pointer. If a second program counter or subroutine pointer were created, all hob could be created - check out the "Rhapsody in Space" article(s) in the old 65 User Notes, circa 1976 (cf. Jake Schwartz disks).

The old 65 User Notes (and later PPC Journal) covered all this in detail. Back when the Web was on paper, the over 5000 members eagerly awaited each one...

Do have fun!
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04-28-2015, 09:06 PM
Post: #8
RE: Synthetic Programming
Thanks to everyone for the great info.

Right after I bought my first HP ( 41CV ) in 1981, I joined PPC, and for several years was hooked on synthetic programming. Also was really impressed by the ingenuity of many PPC members. I had a lot of fun with William Wickes' book and also scanned barcode of a lot of great users' programs. But I never knew that other HP calcs had an undocumented functions discovered.

Thanks,
Bob
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04-30-2015, 04:35 AM
Post: #9
RE: Synthetic Programming
Hi,

Been away and jet lag has caught up, will get back soon. There was an adapter that created synthetics. Some companies took advantage of this such as Beechcraft. They created an interface for the 67 which then prompted in alpha (NNN) for aviation relates algorithms.

I have to dig this up when I get home.

Geoff
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04-30-2015, 08:21 PM
Post: #10
RE: Synthetic Programming
(04-27-2015 03:08 AM)bshoring Wrote:  Other than the HP-41 series, has anyone found a way to do synthetic programming on any other HP RPN machine ?
Bob

A little blast from the past for the 42s - ENJOY!
[attachment=1920]
BEST

SlideRule
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04-10-2022, 09:26 AM
Post: #11
RE: Synthetic Programming
I recently discovered the 15C synthetics article and after reviewing and testing I created a video demonstrating programming the display (adapted from the example provided).

The display encoding is not straightforward so not sure how useful this would be in user programs but it was an interesting exercise. I assume the complexity relates to the hardware used/available at the time.



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