New firmware for the Swissmicros DM15L

[jebedeo]

Hello Everyone,

it's been a long time but I have been making progress. Here is another beta of my new firmware, with way more features.

Key facts:

| -------------------------- | --- HP15C --- | --- LF15C ---- |
| -------------------------- | ------------- | -------------- |
| Internal Data ------------ | BCD --------- | double complex |
| Precision Digits --------- | 10 ---------- | ~ 17 [1] ----- |
| Programming mode --------- | op codes ---- | human readable |
| Stack Size --------------- | 4 ----------- | 4+ ----------- |
| Register Size ------------ | 21 ---------- | 100 ---------- |
| Program Memory ----------- | up to 672 --- | 2000 --------- |
| Program Labels ----------- | 25 ---------- | 100 ---------- |

[1] Following https://math.stackexchange.com/questions...calculator



Current implemented features:

| --------------------- | HP15C | LF15C |
| --------------------- | ----- | ----- |
| Complex numbers ----- | - x - | - x - |
| Programmability ----- | - x - | - x - |
| Statistical Functions | - x - | - x - |
| Integrate ----------- | - x - | ----- |
| Solve --------------- | - x - | ----- |
| Matrix -------------- | - x - | ----- |



I am tidying things up and will create a github repo for this at some point, but for right now give it a try and let me know if you like it!