NP-41 Emulator (may be)

[Chris Chung]

(03-15-2016 08:44 PM)jch Wrote:  Hello Chris,

Amazing project !
My votes :
1) White PCB, like the NP-41, but I prefer the lettering silkscreen placed on the left of the keys.
2) Battery on the bottom / optionally 4 pins header for external battery ?
3) Same layout as NP-41

Unlike the NP-41, you're not planning to have head + keyboard unit ?

Jean-Christophe.

I am actually planning to take away the 2 pcb design from NP-41. Having 2 PCBs is due to cost , as before I switch fabricator, PCBs above 10x10cm increase the cost 5 fold. My new fabricator is more flexible on larger PCBs so there is no need. My experience is that it is more reliable when it is more simplistic. There will be less solder points and source of trouble. If there are needs to have the single head unit (so one can play w/ their own keyboard diy) I am happy to release the PCB design. But my plan is to further simplify both designs and reduce to single PCB.

When there is PCB estate, I will put in "cut-out" line and key pin connector positions so that one can chop the keyboard off and attach a new one. Look closely on the current NP41S PCB, you will see 10 via holes in the middle right under the LCD module to serve this purpose. So once you are bore w/ the unit, you can guillotine out the head unit and play w/ another keyboard. Cherry keys may be?

(03-15-2016 11:11 PM)Helix Wrote:  I will definitely by a NP-41S, but not necessarily in the very first batch, because I prefer a mature product.

My votes:
1) White PCB. It will nicely complement my NP-25.
2) The battery on the top side seems a bit weird at first glance, but it doesn't bother me a lot. One advantage I can see with this design is the ability to use the NP-41S without a case. If the battery is on the bottom, the case is almost necessary.
3) Two Enter keys, for aesthetical reasons, because I like when the keys are perfectly aligned in a keyboard. Since there will be two versions, NP-41S and NP-41, you can make two different layouts. The NP-41 layout is perfect for the NP-41!


Here are some comments I've already made about the writings:

- The "E-" "E+" and "CLE" writing should be replaced by "Σ-" "Σ-" and "CLΣ", like in the last versions of the NP-25: http://www.hpmuseum.org/forum/attachment.php?aid=2702
- Also, the "R v" writing to simulate the "R↓" key is not very pleasing. In the NP-25 of the link above, the writing is much better.
- "x<y?" should be replaced by "x<=y?". I understand that space was limited on the NP-25 PCB, but there is plenty of room in the NP-41.

2) I will actually try to have multiple solder points so that one can solder the battery holder on either side. Just need to play w/ various layouts.
3) I agree w/ you. It will probably stay the same (I got to choose) but one can always choose to not solder the second enter key.

Good catch on key legends. There are certain limitations w/ Fritzing, those characters are hi-asciis and I will make the adjustment for the new PCBs.