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Fix incorrect solution in the Registers section #186

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Fix incorrect solution in the Registers section #186

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21 changes: 11 additions & 10 deletions src/part1/registers.md
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Expand Up @@ -68,8 +68,7 @@ Let's see how, with our first assembly instructions!

:::challenge Challenge!

1. You store the number `16` into the register `bc`, then store the number `14` into the register `c`. What is the current value of the register `bc`?
(HINT: you might need to do some conversions :>)
1. You store the number `256` into the register `bc`, then store the number `14` into the register `c`. What is the current value of the register `bc`?
2. Can you store numbers larger than 255 into a single register? Why or why not?


Expand All @@ -79,18 +78,20 @@ Let's see how, with our first assembly instructions!

### Answer 1
---
By converting `256` and `14` to their __BASE 2__ format
First, we convert `256` to 16-bit binary and `14` to 8-bit binary (since `BC` is a 16-bit register and `C` is its lower 8 bits):

> (`%0000 0001 0000 0000` & `%0000 0000 0000 1110` respectively)
```
256 = %0000 0001 0000 0000
14 = %0000 1110
```

The computer will update the register `bc` with the format
Then we update the register `BC` by replacing only the lower 8 bits (the `C` portion) with the new value:

> `0000 0001 XXXX XXXX`
where you replace the _X_ 's with `%0000 1110`.
```
%0000 0001 0000 0000 -> %0000 0001 0000 1110
```

This is possible only because you are updating the 4 bits in register `c`. Not the full 16.

This results in the answer `0001 1110` or `30`.
This results in the value `270`.

### Answer 2
---
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