DM42 available for order!!!

[salvomic]

(12-22-2017 01:47 PM)jebem Wrote:  Apparently it is not possible to place orders anymore, by using their portal order page:
When you type in anumber higher than zero in the Qty field, the message is:
"DM42 limited stock...qty changed.
For preorders please contact michael@swissmicros.com by email"

About preorder, I wonder if for whom requested a confirmation email and doesn't received it is better waiting that email or to order as soon as possible, thank you.

Salvo

[rprosperi]

(12-22-2017 01:47 PM)jebem Wrote:  Apparently it is not possible to place orders anymore, by using their portal order page:
When you type in anumber higher than zero in the Qty field, the message is:
"DM42 limited stock...qty changed.
For preorders please contact michael@swissmicros.com by email"

I can put a "1" in the qty field, I only get that message when using a number higher than 1 (perhaps a good tactic to prevent someone buying multiple units early in the sales window, to prevent... um.... eBay sales at unreasonably high prices?)

[Michael de Estrada]

(12-22-2017 02:16 PM)rprosperi Wrote:  

(12-22-2017 01:47 PM)jebem Wrote:  Apparently it is not possible to place orders anymore, by using their portal order page:
When you type in anumber higher than zero in the Qty field, the message is:
"DM42 limited stock...qty changed.
For preorders please contact michael@swissmicros.com by email"

I can put a "1" in the qty field, I only get that message when using a number higher than 1 (perhaps a good tactic to prevent someone buying multiple units early in the sales window, to prevent... um.... eBay sales at unreasonably high prices?)

Uh, no.

[rprosperi]

(12-22-2017 03:15 PM)Michael de Estrada Wrote:  Uh, no.

No longer works here. Must be sold out!!

[Michael de Estrada]

(12-22-2017 03:27 PM)rprosperi Wrote:  

(12-22-2017 03:15 PM)Michael de Estrada Wrote:  Uh, no.

No longer works here. Must be sold out!!

I think they were sold out as of last Tuesday, but maybe some glitch in the ordering system allows you to occasionaly enter a non zero quantity.

[rprosperi]

(12-22-2017 03:38 PM)Michael de Estrada Wrote:  I think they were sold out as of last Tuesday, but maybe some glitch in the ordering system allows you to occasionaly enter a non zero quantity.

Not sure either. Was unexpected that it behaved that way, as limiting to 1 seems an unnecessary precaution...

Being sold out that quickly is an excellent problem to have; maybe Michael and David got the best Christmas gift among all of us here.

[Logan]

May this be an indication of the RPN revolution to come!

[Jeff O.]

(12-20-2017 06:23 AM)Michael de Estrada Wrote:  

(12-19-2017 06:31 PM)Logan Wrote:  I've experienced a little bounce too several times but part of it could be me not being used to how hard I need to press.

Go into SETUP, 3. Settings and select 5. Slow Auto-repeat. This solved the bounce problem with hard buttons for me.

I am not sure that I understand why selecting “slow auto-repeat” would have any effect on key bounce behavior. As far as I can tell, slow auto-repeat seems to extend the time you must hold a key down before it starts auto-repeating. So the keyboard handling routine is looking for an extended key press of some duration. For de-bouncing, isn’t the issue, from the keyboard handler’s perspective, “hey, I just detected a key press and release, how long should I wait before accepting another press of the same key as an intentional second press of that key?” (Unless you mean that selecting slow auto-repeat allows you to firmly press and hold the key briefly to ensure no bounce while also avoiding auto-repeat.)

With the above said, I’ll note that I have also experienced some key bounce. Nothing major, mostly related as far as I can tell to not firmly pressing the key. But I’d like to see some attention given to eliminating it if possible.

(I have no experience with designing keyboard hardware, or implementing software to detect keyboard operation. If the above demonstrates that lack of knowledge, please feel free to set me straight.)

[jebem]

(12-22-2017 07:17 PM)Jeff O. Wrote:  For de-bouncing, isn’t the issue, from the keyboard handler’s perspective, “hey, I just detected a key press and release, how long should I wait before accepting another press of the same key as an intentional second press of that key?”

That is the correct algorithm to detect a proper key register.
As soon as a ON key is detected by the software routine, it must register it and enter a waiting cycle using a counter for at least, say a 100mS, before listening again to new key presses (the keyboard routine can use a basic poll scanning method, or else a more sophisticated hardware interrupt handler).

In this way, the multiple successive ON-OFF-ON impulses resulting from pressing a key, no matter how good is the key or how hard you press it, will be interpreted as a single key press.

Of course this bouncing issue will be worse on lower quality keyboards (easily oxidizable metal contacts requiring more mechanical pressure to minimize the ON-OFF-ON train pulses), but as far as I know, it is impossible to eliminate it at the hardware level alone.
A proper debouching routine must handle it correctly, even if it takes a longer waiting cycle, like 200mS or even 300mS, to make sure that, at very least, each key registers only once when pressed.

[Michael de Estrada]

Regardless, all I can say is that I’ve not experienced a single case of key bounce since I set the keyboard to Slow Auto-repeat. Prior to that, I had multiple instances when I first got the calculator.

[Dave Britten]

(12-22-2017 08:16 PM)jebem Wrote:  Of course this bouncing issue will be worse on lower quality keyboards (easily oxidizable metal contacts requiring more mechanical pressure to minimize the ON-OFF-ON train pulses), but as far as I know, it is impossible to eliminate it at the hardware level alone.

A bit of capacitance can do the trick.