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Dave Britten · 01-06-2022, 03:47 PM

I bought some more used-but-blank mag cards from ebay (I don't have a problem, I can quit whenever I want), and among them was one card with no markings but clipped corners. Intrigued, I checked it with VER on my 41, and it reported a 67 program on both sides. So I fed it into my 97 and printed the listing. The card read fine first try on both calcs, so I don't think we're looking at any corruption here - the checksum would have caught that anyway. But I can't tell if I'm looking at the incoherent ramblings of a madman, or if there's some meaning here. What's going on with all the flag setting and clearing???

https://i.imgur.com/Q0XRXPu.jpg

Thomas Okken · 01-06-2022, 03:56 PM

Lots of flag setting but no flag testing... Something meant to run on an HP-97S perhaps?

Dave Britten · (This post was last modified: 01-06-2022 04:12 PM by Dave Britten.)

(01-06-2022 03:56 PM)Thomas Okken Wrote: Lots of flag setting but no flag testing... Something meant to run on an HP-97S perhaps?

Oh, good thought. Would that have some kind of useful effect on that model? I'm not familiar enough with the 97S to know how the I/O port is controlled. It could explain some of the other seemingly nonsensical things going on too.

EDIT: I think I see something to support your theory. The 97S manual says the four flags are used for controlling output lines on the interface (presumably in addition to their normal function in programming). The manual also says the interface only has a "continue at A" mechanism for triggering program execution. Looking at the program listing, there's a LBL A that simply does GTO 6. LBL 6 does a little dance with flags 2 and 3, and then stops. Hmm...

AndiGer · (This post was last modified: 01-06-2022 04:44 PM by AndiGer.)

Consider it could be a program for the HP-97S.
2 times LBLA.
Second LBLA leads to CF3 + R/S inside execution of LBL6 - waiting for input from the 97S BCD box.
First LBLA leads to CF3 + PSE if x>=0 inside execution of LBL7. If during PSE no input arrives flag 3 is set to disable input and do the iteration inside LBL7 until x<0.

I didn't inspect the program further but an idea. But no idea what could have been connected to the BCD box - if my assuption is right.

Andi

Edit: thomas beat me :-).

Dave Britten · 01-06-2022, 05:36 PM

(01-06-2022 04:43 PM)AndiGer Wrote: Consider it could be a program for the HP-97S.
2 times LBLA.
Second LBLA leads to CF3 + R/S inside execution of LBL6 - waiting for input from the 97S BCD box.
First LBLA leads to CF3 + PSE if x>=0 inside execution of LBL7. If during PSE no input arrives flag 3 is set to disable input and do the iteration inside LBL7 until x<0.

I didn't inspect the program further but an idea. But no idea what could have been connected to the BCD box - if my assuption is right.

Andi

Edit: thomas beat me :-).

Yeah, I think if it is a 97S program - and there is definitely some convincing evidence that it is - there wouldn't be any way to fully understand what it's doing without knowing what hardware it was connected to. But knowing it's probably a 97S program and not just some gibberish is good enough for me. Smile

toml_12953 · 01-07-2022, 04:36 AM

Just don't read it out loud or you'll summon a demon. That happens in almost every horror movie I've ever seen!

Dave Britten · 01-07-2022, 12:32 PM

(01-07-2022 04:36 AM)toml_12953 Wrote: Just don't read it out loud or you'll summon a demon. That happens in almost every horror movie I've ever seen!

Oh. Uh... I need to make some calls...