HP 67/97 Special Message Cards, videos of...
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09-03-2019, 10:08 PM
(This post was last modified: 09-03-2019 10:13 PM by Greg.)
Post: #5
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RE: HP 67/97 Special Message Cards, videos of...
Hi DanM,
This is now a few years after your post and you've probably moved on to other things, but ... Word cards were all the rage in 1976-1978. I got my HP-67 in 1978 so I came in on the tail end. The leading edge was an article in 65 Notes V4N1 (Jan 1977) by Louis Cargill. He and someone named Gene were responsible for working out the program codes for the HP-67 and, during that process, they discovered you could get Non-Normalized Numbers (NNNs) like 0.00000002 x 10^0 (not a valid number in SCI notation) and these produced long delays in divides and strange effects in the display. The more interesting NNNs had letters in them and Louis and Gene were able to determine that the letters for "Error" and "Crd" came from specific hexadecimal digits (a-f) in positions within registers. Their work is how we know that digits a-f display as "rCodE " (f gives a blank space). Much of the work on HP-67 tricks stems from their work over what was probably a lot of very intense nights. We may even owe the alphanumeric display of the HP-41 to the fact that words became a thing as a result. Perhaps when the HP-41 came out, the hoops we'd had to go through to get words on the '67 were forgotten. It is easy to forget as there was a lot to it. Newer initiates to HP calculators probably never even heard of words on a HP-67 - much less the process to get them. To refresh older member's memories and explain for newer members: The process for creating words involves getting hex digits (specifically a-f) in parts of the mantissa in a storage register. The HP-67 stores numbers internally in SCI notation. There are 14 digits stored for every number. The format is: mantissa sign, 10 digit mantissa, exponent sign, 2 digit exponent. Sign is "0" for +ve or "9" for -ve. The values normally look like this: 05000000000000 = +5.0 x 10^+00 ie 5 01230000000002 = +1.23 x 10^+02 ie 123 This is why 0.00000002 x 10^+00 is a Non-Normalized Number. It is stored as: 00000000020000 when it should be stored as 02000000000992 (992 in the exponent sign and value means -8). Words involve "numbers" like 0ec54f1dcff009. If you can get that into STOrage register 6, RCL 6 will produce "Easy Ida" (Eo54 1do) in the display. "4" on a HP-67 looks like a "Y" and the "o" looks like a small square. Seeing that as an "a" isn't a stretch. How do you put stuff like that in a STOrage register? The process was not very straight forward in 1977. Louis and Gene used a HP-65 and a HP-67 and wrote magnetic bits from one onto cards for the other. Another approach they used involved turning the HP-67 off during a card write. That allowed them to put a DATA header (f W/DATA) on a PROGram card. You'd key in program steps, save them, overwrite the header, and then read the program steps back in as DATA. Data is (should be) always 0-9. Program steps are two hexadecimal digits so each step is two "digits". You get 00-FF instead of 00-09,10-19,20,...,99. Another approach that came a little later, involved program step 992. If you got to program step 992, you're keying program steps into the wrong part of the calculator's internal memory. You're keying steps directly into the STOrage registers! The "phase I interrupt switches" that were mentioned in the post quoted by SlideRule enabled this approach. The special hardware wasn't strictly necessary. You could achieve the same result by: sliding the HP-67 power switch to the point where it just turned on, and then pressing the switch in slightly. This broke the circuit briefly and did the same thing as the special hardware. It does wear out the power switch though (eventually, and due to sparking rather than mechanical failure). The easiest approach was to get a card after someone else had created them. Once they were in STOrage registers you could write them to mag cards and read them back - just like any other DATA. Given that Gene of the Forum was tinkering with these in 1976 and that the original article on them was published in Jan 1977, one might draw a conclusion about the Gene mentioned in the article. Modern Tricks (Cheating). These days, with what we have available now, there is an even easier approach. It is in many ways cheating but it is very easy to do. All you need is an emulator that allows access to the calculator internals. My hp67u (http://www.sydneysmith.com/products/gss-...n/app.html) or Teenix's emulator (http://www.teenix.org/) both allow you to do this. With mine, you tap the calculator display to bring up a menu, tap Data and paste the following in to the input box: Code:
With Tony's emulator the process is similar. Run CCE33.EXE with HP-67 selected, right-click, choose "For the inquisitive...", make sure the calculator is ON and that MEMORY Bank 0 is showing. Click on a register and key in 14 digits from the list above. Bank 0 registers 0-9 are STOrage registers 0-9. Bank 0 registers 10-14 are STOrage registers A-E. You then click RCL 0-9 or A-E to display the word you keyed in. Other words can easily be created in my or Tony's emulators by keying in hex digits where you need them. In mine, just go back to the Data input box and change digits. Mine needs the leading single quote mark for it to copy what follows it directly into the STOrage registers. There are other emulators that may allow you to use NNNs. To cover off some of the common ones ... Bernhard's emulator (http://panamatik.de/html/hp-67.html) doesn't provide access to the calculator's internals and his card format doesn't mention a 14BCD override (like the '0955f67ffff009 trick I use). So that doesn't seem to support NNNs (yet?). The Cuvee Software emulator doesn't match the original internals so it is unrealistic to expect it to support NNNs. Its strengths are numerous; but in other areas. (I still remember the times when I needed a 225th program step in a HP-67, and the effort required to prune that back to 224.) It has lots of enhancements so I can see why many forum users love it, but NNNs are probably not for it. If you have them, the old nonpareil emulator and Jacques Laporte's java one probably do support NNNs. The Videos. What's in the videos uses an extra technique that shows numbers w/out a decimal point. However, with a decimal point, the "numbers" involved are: Code:
Note: the HP-67 rounds what is displayed to the display precision (the DSP n setting). The rounding process will normalize, Non-Normalized Numbers so things like " Error. " ('0eaacafffff004) show in FIX 2 mode as as 51131.66. To avoid rounding, always put the dot at the right-most position (use 009 in the three exponent digits), or press DSP 9 before displaying a word with an embedded decimal point. For the hp67u: Code:
and so on .... Don't forget the most important tip from that era: be really careful with NNNs on a HP-97. They mess up timings or produce unprintable characters that end up burning out the printer. - Greg from sydneysmith.com |
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Messages In This Thread |
HP 67/97 Special Message Cards, videos of... - DanM - 12-19-2017, 09:25 PM
RE: HP 67/97 Special Message Cards, videos of... - SlideRule - 12-20-2017, 01:09 AM
RE: HP 67/97 Special Message Cards, videos of... - Gene - 12-20-2017, 01:42 AM
RE: HP 67/97 Special Message Cards, videos of... - DanM - 12-20-2017, 01:25 PM
RE: HP 67/97 Special Message Cards, videos of... - Greg - 09-03-2019 10:08 PM
RE: HP 67/97 Special Message Cards, videos of... - Archilog - 09-04-2019, 10:59 AM
RE: HP 67/97 Special Message Cards, videos of... - Gene - 09-04-2019, 06:56 PM
RE: HP 67/97 Special Message Cards, videos of... - Jake Schwartz - 09-04-2019, 08:26 PM
RE: HP 67/97 Special Message Cards, videos of... - Archilog - 09-04-2019, 08:02 PM
RE: HP 67/97 Special Message Cards, videos of... - Greg - 09-04-2019, 09:24 PM
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