Reading old HP-65 program cards

[Dave Britten]

(03-03-2021 03:09 PM)CY-CL Wrote:  This is really an interesting NASA HP-65 calculator. No connections plugs for the charger are present !!!!

Interesting. It sort of looks like they just stuck a little plastic cover over the charging connector, though it seems to be an exact match for the plastic the calculator is made of.

[Gene Dorr]

Yes that is interesting -- I've looked at all those images many times and never noticed that before. It doesn't surprise me though -- as part of the documented procedure for preparing the "calculator kit" for flight, they put tape over the battery contacts of each of the six spare batteries packs. If you look at the photo of the three technicians preparing the calculators for flight (see the web page I've created -- hp65.genedorr.com -- under "Information from HP"), you'll see the the fellow on the right (Mason Mines) is placing tape over the contacts on one of the spare battery packs. Obviously they didn't want to chance any floating debris shorting the contacts of the calculator, either.

From what I've been able to gather, only one set of program cards was flown, and the set pictured is very probably the one flown. They *did* use them in flight -- the "ATS Pointing Program" was the primary means of getting the values used to point the spacecraft's high-gain antenna at the ATS-6 relay satellite. And while the maneuvering solutions were described as "backup" to the Apollo Guidance Computer (AGC), that doesn't mean they would only run them if the AGC failed: what really happened is that they used the HP-65 to compute the solutions for the engine burns, and then compared the resultant values to those they got from the AGC. It was, in a way, a technology demonstration, and they wanted to evaluate whether the HP-65 programs would produce useful results.

There are a lot of links in the web page I created -- including a link to the Smithsonian page. If you're at all interested in this topic, I really recommend checking it out. It has virtually everything I've found, except for the rather large "Qualification Test Report" document -- I had to submit a FOIA request to get that, and it's a bit too large (31Mb -- 111 pages) to provide via my web hosting service (plus, the first page of the PDF file is the response letter from NASA, which contains personal information I'd rather remove before making it publicly available).

[toml_12953]

(03-03-2021 03:09 PM)CY-CL Wrote:  This is really an interesting NASA HP-65 calculator. No connections plugs for the charger are present !!!!

I see the connection socket, right at the top where it should be.

[Gene Dorr]

Yes but, at that angle you should clearly see the charging pins. This photo of an HP-35 is at a much more oblique angle, but you can still see the pins.

[Dave Britten]

Quick recreation matching the shot angle as closely as I could:

https://i.imgur.com/yxV1ap6.jpg

The charging pins should definitely be plainly visible.

[Massimo Gnerucci]

(03-03-2021 10:58 AM)Didier Lachieze Wrote:  You can see the cards here. And the whole NASA HP-65 picture set here.

One could ask to try to read the NSR-1 card, since it appears twice.

[albertofenini]

That would be amazing !!!
We have restored quite a few HP65s
In our experience writing has been usually more tricky than reading
Of all of our units all can read the majority of cards whether it was a standard pac, and believe me we mixed them a lot, or an application pac or even a previous owner card
Few units have given us a hard time with the WA and WB signals but replacing the amplifiers has mostly been a good fix

Reading, and copying , those cards would be close to find the holy grail of the HP65

Good luck with that and let us know !!!!
Take care

[albertofenini]

That’s not a standard socket
The usual socket is a single rectangular shaped hole with the pins
Here it looks like there are two although thinner holes rather than only one
May be they where using a different connector or the inside was modified
If they had to plug-in and plug-out wearing gloves the normal connector was probably not the most practical solution
I doubt it they were only running on batteries ...

(03-03-2021 04:08 PM)toml_12953 Wrote:  

(03-03-2021 03:09 PM)CY-CL Wrote:  This is really an interesting NASA HP-65 calculator. No connections plugs for the charger are present !!!!

I see the connection socket, right at the top where it should be.

[Gene Dorr]

The "kit" flown on the mission consisted of two HP-65s (each with a battery pack installed), six spare 82001A battery packs, the program cards, and the standard HP-65 "Quick Reference Guide" -- all packaged up into custom-made cases fashioned out of non-flammable beta cloth (the same material used for the outer layer of the spacesuits). Access to the charging socket would be unnecessary in flight.

[albertofenini]

IMHO Either they were carrying an external battery charger, which existed at the time,
or I doubt it that a backup system as it was supposed to be and given the amount of
cards to be read in case of necessity was based on six, although fully charged, battery packs ... but that’s just my two cents

[albertofenini]

Also think about this scenario ...
If you need to use the HP65 it means the main system is not properly working
So you load you card start your calculation and all and then ... if you need to change battery you loose everything and start over again with the new battery ?
Seems just too risky to me when you could have the unit plugged and working for all the necessary time ...

[Gene Dorr]

No, no battery charger, no external charging unit, just the items I listed. There was no way to power a charger on board the Apollo CM anyway. There was only a single rendezvous where the Apollo was the active vehicle, so we're only talking a few hours of use. Six spare batteries was serious overkill for the amount of use anticipated, but that was the philosophy of the program back then.

[SlideRule]

An excerpt from History of Space Shuttle Rendevous, JSC-63400, October 2011, 316 pages.

" On-Board Maneuver Targeting
   The Apollo CSM computer used the same targeting
and relative navigation algorithms as were used for
Skylab rendezvous. However, the paper chart solutions
were replaced by targeting algorithms on a Hewlett-
Packard HP-65 calculator with a magnetic card reader.
Back-up targeting could be performed for the coelliptic
(NSR), Terminal Phase Initiation and Mid-Course
Correction Maneuvers. " page 61

An excellent read!!

Best!
SlideRule

[[kby]]

If you mean what instructions the 6-bit opcodes decode into, that information is in old 65-notes issues. There is, as you noticed, no header.

However, I would only try this technique as a last resort if the cards won’t read. First, I’m not sure it’s non-destructive. Second, if the card can’t read in the calculator,it likely won’t have enough to read visually either. There is minimal error checking (many parity? It’s documented but I don’t remember offhand), so a card is more like to misread rather than get an error, I think. Generally I have found cards mostly read, both ones I’ve made and the commercial ones from HP. The usual culprit if they look ok is magnetic fields; it doesn’t seem to take much to demagnetize them.

I have had one 65 that I was certain had not been opened that had a good card reader in it and its roller did not look like the usual polyurethane one; I recall it being black. I have no idea why that one was unique.

I’d certainly volunteer to try to read them on one of my -65s. I don’t have any magna-see, iron filings, or trichloroethylene.-kby

(03-02-2021 11:53 PM)Gene Dorr Wrote:  That's certainly helpful. It looks like there's no header at all, just the raw program memory. Any clue where I might find the decoding of the 6-bit values beyond what is shown in the example?

[rprosperi]

(03-03-2021 03:02 PM)Didier Lachieze Wrote:  Well, I think that the "Mfg by" applies only to the case, not to the HP-65...

I don't believe GE actually manufactured this case either. But selling to the Gov't is something which they have a lot of experience doing...

The lack of power pins on the back is mighty interesting!

[teenix]

(03-04-2021 03:36 AM)rprosperi Wrote:  

(03-03-2021 03:02 PM)Didier Lachieze Wrote:  Well, I think that the "Mfg by" applies only to the case, not to the HP-65...

I don't believe GE actually manufactured this case either. But selling to the Gov't is something which they have a lot of experience doing...

The lack of power pins on the back is mighty interesting!

Maybe with the super cautious approach to missions, they decided that open battery contacts presented too much of a possibility of shorts with something and didn't want to add the risk.

cheers

Tony

[[kby]]

I don’t have time right now, but, although I think this list looks mostly ok, there are a couple that don’t look right. The ones I notice would not be relevant to any card you get from NASA as they are opcodes that don’t correspond to keystrokes that can be programmed. In particular, 39 (octal 47) will show as a CHS in PRGM mode, but does not act that way with certain prefixes. 40 (octal 50) will appear as 02, but ‘executes’ as SST.

This info is in 65-notes V3 N7 p3 in the article titled “What are the Limits” by Lou Cargile and Gene Hoffman. It is an excellent but somewhat dense read. It includes examples of using the Magna-See although the pictures aren’t all that great due to the circa mid 1970s photocopy quality.

-kby

(03-03-2021 12:28 AM)teenix Wrote:  

(03-02-2021 11:53 PM)Gene Dorr Wrote:  That's certainly helpful. It looks like there's no header at all, just the raw program memory. Any clue where I might find the decoding of the 6-bit values beyond what is shown in the example?

0 NOP
1 STO 4
2 3
3 2
4 1
5 STO 6
6 x
7 x!=y?
8 g
9 ROLUP
10 RCL
11 STO
12 f-1
13 ROLDN
14 f
15 RCL 8
16 RCL 7
17 X<>Y
18 6
19 5
20 4
21 RCL 6
22 +
23 RCL 4
24 E
25 x=y?
26 D
27 C
28 B
29 RCL 5
30 A
31 RCL 3
32 RCL 2
33 RCL 1
34 R/S
35 .
36 0
37 STO 7
38 /
39 A
40 B
41 x>y?
42 RTN
43 LBL
44 GTO
45 STO 5
46 DSP
47 STO 3
48 STO 2
49 STO 1
50 9
51 8
52 7
53 STO 8
54 -
55 x<=y?
56 CLx
57 Sub Pointer
58 EEX
59 CHS
60 LSTx
61 Pointer
62 ENTER
63 Top Of Memory

cheers

Tony

[Gene Dorr]

GE had a general management contract during the Apollo program, which I gather covered a lot of things. In the "Qualification Test Report" document that I cited, there is documentation that GE was specifically contracted to procure 3 HP-65s to be used for ASTP (2 for qualification and flight, 1 for program development), plus 20 spare battery packs, plus any additional program cards deemed necessary. This was covered under contract NAS 9-13867. Apparently the preparation of the soft materials (the 2 calculator cases, a holder for the program cards, and the overall case for the whole lot as stowed on the spacecraft) also fell under this contract. McDonnell Douglas Technical Services Company was contracted (NAS 9-14023) to do the program development for the calculators.

[Gene Dorr]

(03-04-2021 04:08 AM)[kby] Wrote:  This info is in 65-notes V3 N7 p3 in the article titled “What are the Limits” by Lou Cargile and Gene Hoffman. It is an excellent but somewhat dense read. It includes examples of using the Magna-See although the pictures aren’t all that great due to the circa mid 1970s photocopy quality.

Thanks much for that citation. Extremely helpful!

[Gene Dorr]

(03-04-2021 03:33 AM)[kby] Wrote:  I would only try this technique as a last resort if the cards won’t read. First, I’m not sure it’s non-destructive. Second, if the card can’t read in the calculator, it likely won’t have enough to read visually either.

Indeed, I would agree on both counts. The tricky bit, in any case, would be to convince the curators that handling these artifacts is worth the "risk." My understanding is that they are very much oriented toward "preservation" versus "interpretation."

But I haven't yet given up on tracking down actual commented program listings, which would actually be far more interesting than the bare keystroke listings anyway.