Search found 21 matches

by Jebem
Sat May 18, 2019 6:31 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 75
Views: 3888

Re: DM42- clock losing time

Ah yes, but what was the average temperature? Humidity? Where in the lunar cycle are we? What was the background radiation during this period? These are all important to know as well. Yeah it is funny :) But one working in the electronics field would know that using regular smd capacitors in the os...
by Jebem
Sun May 12, 2019 3:29 pm
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 75
Views: 3888

Re: DM42- clock losing time

the worst case scenario for the reported clock issues should be around 6 minutes after 6 months. Should... I could throw in the ring 38 minutes loss after 14 months. Hans Clearly this would require investigation to find the roor cause(s). The hardware oscillator must be stable and within the requir...
by Jebem
Sun May 12, 2019 7:32 am
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 75
Views: 3888

Re: DM42- clock losing time

Bom dia Jose, y muito obrigado for pointing to your comprehensive investigation. I admit I've read it a year ago but didn't remember. BTW, please note you called the quartz a "high precision crystal" in your post of 2018-02-11 and didn't relativize this statement any later AFAICS. Guten Morgen, pro...
by Jebem
Sat May 11, 2019 10:48 pm
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 75
Views: 3888

Re: DM42- clock losing time

OK, 20ppm corresponds to 10.5 minutes per year (that's far worse than any cheap quartz watch sold nowadays). But now we must talk about the 20ppm - how do you get them? These are regular electronics components found in shops. Nothing fancing like the ones used in professional and lab equipments whe...
by Jebem
Sat May 11, 2019 7:03 pm
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 75
Views: 3888

Re: DM42- clock losing time

I don't remember to see any adverts from the manufacturer concerning the precision of the clock but i might be wrong. Nor do I. Though it's not a matter of specification or advertising, it's just a matter of customer expectation. If and when you include something like an RT C in a calculator nowada...
by Jebem
Fri May 10, 2019 6:04 pm
Forum: Usage tips, tricks and problem reports
Topic: DM42- clock losing time
Replies: 75
Views: 3888

Re: DM42- clock losing time

Despite using a 32768khz reference device (be it a crystal or a resonator or whatever they are using on it), the time depended on two factors: 1. Hardware oscillator circuitry precision. The hardware design, namely the load components used affect the frequency that will not be exactly 32768khz if th...
by Jebem
Fri Mar 30, 2018 9:36 am
Forum: Discuss!
Topic: Why was Stainless Steel used for the DM42?
Replies: 12
Views: 3088

Re: Why was Stainless Steel used for the DM42?

My less than two cents humble opinion here... A metal back cover had to be used in this design because: 1. The way the back cover is joined to the front cover requires a material with enough strength to cope with the force applied to it when opening and closing the calculator. A plastic cover would ...
by Jebem
Wed Mar 14, 2018 5:50 pm
Forum: Discuss!
Topic: Tribute to Stephen Hawking
Replies: 4
Views: 1582

Re: Tribute to Stephen Hawking

it was a shock to ear the tv news this morning.
Somehow I realized what I always knew - we are not eternal, but for the famous ones I always assumed they would live forever.
RIP.
by Jebem
Fri Mar 02, 2018 8:34 am
Forum: Usage tips, tricks and problem reports
Topic: 82240B AC adapter?
Replies: 14
Views: 2362

Re: 82240B AC adapter?

I'm using an adapter that provides 12 VDC at 2 amps. It came from an old external hard drive setup. Prints forever with no batteries. Absolutely right. No batteries needed when using the external power adapter. Why? Because the 6VDC battery cells are connected in parallel with the internal power su...
by Jebem
Thu Feb 22, 2018 2:28 pm
Forum: Discuss!
Topic: Try searching for "help file" and "qspi". Not so easy...
Replies: 11
Views: 2063

Re: Try searching for "help file" and "qspi". Not so easy...

That is why I tend to use google for searching things in the net, like this:
help file qspi site:forum.swissmicros.com

I got just 5 answers using the above search string, but got 7 if looking only for qspi, and 26 if looking for help file.