Deli DL-1704 Scientific Calculator available in the southern Africa region

[jebem]

I have been busy in the last weeks in the southern Africa region.
Having time to kill during the weekends, I walked around the Maputo city.
I was not surprised to see some HP calculators models in the shops, namely the HP-50G, despite the high asking price of 6000MTN (about 150 USD).

Maputo city is full of street markets and among the more popular brands like CASIO, I found this Deli brand that I never heard of before.
So I bought this DL-1704 pocket calculator for 250MTN.
I didn't even try to bargain. I was in a hurry to go back to my hotel before the storm arrival announced by the distant regular thunders, joined by very hot and humid air conditions.

Back at the hotel I had a closer look to this Deli DL-1704 calculator.
Nothing special, really, this a light small pocket non programmable machine and it looks like yet another clone of the usual basic Casio/Sharp/Canon/Citizen brands, I thought.

The colorful card box announces 2 years warranty, 10 digits, 56 functions, auto power off, plastic keys, sliding cover, and ability to convert between deg/rad/grads.
Inside there is a plastic bag with the calculator and a small user's manual inside.

The 13 pages user's manual contents is poor and there are no published specifications. On top of this, the Battery Replacement information is wrong for this specific model (it states LR44 x 2) and suggests to press RESET to recover from error situations when this model do not have it.

Then I did the Calculator Forensics test and to my surprise, it came out with exactly the same result as reported for the HP-33S and HP-35S, no more no less.

To get the forensics result for this machine:
1. Selected Degrees mode.
2. Typed: 9 sin cos tan 2ndF tan 2ndF cos 2ndF sin
Result1 = 8.99999986
3. Get remaining digits, typed: Result1 - 8.99999 x 1000000
Result2 = 9.86001
4. Final result = 8.99999986001

I would say that this suggests a common firmware base between this Deli model and the HP-33S/35S manufactured by Kinpo Electronics.

The processor can't be the Sunplus SPLB31A used in the HP-35S, as it requires a absolute minimum of 2.2 Volt.
This calculator runs from a single LR44 1.5V coin battery, so the processor must be able to run from a minimum of around 1.2V, like the Sunplus SPL081A, for instance. Unfortunately the chip is not identified in the PCB.


Browsing the Internet, I can only find Chinese/Russian suppliers, and a couple of references in listings of approved calculators from Australian schools.

Is anyone aware of this brand?





Manufacturing date: Sept-2014.




Forensics test. Final result = 8.99999986001




As usual, I have opened the machine for inspection.
Extremely easy to open. Just remove the 6 steel screws and remove the back cover.

The PCB has the reference DL1704FL YX51941-1, date of 2012.06.12.
So this design is dated already, and Deli site is not advertising it anymore.

Note the Reset key contacts on the PCB, despite missing the Reset hole on the back cover.




Colorful card box package.



Now that I'm back home and able to compare it with other machines, I find the keyboard layout, lcd display elements and case build to be very similar to the Citizen's pocket calculators like the SR-35N / SR-135N series, for instance.
Although the forensics test do not match, as my SR-35N gives me a result of 8.99999863704, the same as for my other landscape format SRP-175.




Edited to correct some typos and add some details.

[Gerson W. Barbosa]

(11-02-2015 06:35 PM)jebem Wrote:  Then I did the Calculator Forensics test and to my surprise, it came out with exactly the same result as reported for the HP-33S and HP-35S, no more no less.

To get the forensics result for this machine:
1. Selected Degrees mode.
2. Typed: 9 sin cos tan 2ndF tan 2ndF cos 2ndF sin
Result1 = 8.99999986
3. Get remaining digits, typed: Result1 - 8.99999 x 1000000
Result2 = 9.86001
4. Final result = 8.99999986001

I would say that this suggests a common firmware base between this Deli model and the HP-33S/35S manufactured by Kinpo Electronics.

Very interesting! Does it give the same results of the hp33s/35s for cos(x) near 90 degrees? If so, this might confirm your finding.

http://www.hpmuseum.org/cgi-sys/cgiwrap/...989#104060

Gerson.

[jebem]

(11-04-2015 01:16 AM)Gerson W. Barbosa Wrote:  Does it give the same results of the hp33s/35s for cos(x) near 90 degrees?

This looks like a mixed bag, as it do not shows the HP-33S/35S cos(89.9999999) bug.
I have used one of my HP-35S for comparison.

While the HP-35S indeed gives a result = 1.74532,this Deli DL-1704 is able to give the result = 1.745322925199.

What I have done to get the above result using the DL-1704:

Typed: 89.9999999 cos
Result1: 0.000000001

Typed: x 1 EXP 9 =
Result2: 1.7453229252

Typed: - 1.74532 =
Result3: 0.000009251

Typed: x 1 EXP 9 =
Resullt4: 9251.99