@cyptography if you want to learn how to do it by hand it literally takes a few minutes to learn. In fact boom MINI TUTORIAL TIME.

note: this is assuming we are working in 8 bit binary.

Binary is a combination of 1's and 0's (obviously). Each 1 and 0 represent a bit of data. Once you have 8 bits you get a byte. Bytes are used to represent data, typically a number, this is referred to as the decimal value, NOT to be mistaken with an integer(Integers can go negative which requires a signing bit and I wont get into that).

The way you figure out the decimal (DEC) of a byte is simple addition in tandem with powers of two. Each bit represents a power of two, so the 8 bits in a byte represent 1, 2, 4, 8, 16, 32, 64, 128 respectively. Now this is where the boolean part of binary comes in. 1 is true and 0 is false. So if you have 01000010 that means that the bit's for 2 and 64 are true, meaning you add them. This gives a total of 66. 8 bit binary can range from 0 (00000000) to 255 (11111111). This is all you need to know how to get a DEC value from binary.

To convert binary to ASCII you need to know the binary value convert it to decimal THEN the decimal value for that ASCII character.

For this you can use an ASCII chart like the one below. Or you can just remember capitol "A" has a dec value of 65 and lower case "a" has a dec of 97. You will also notice the HEX value which is just a 16 bit representation of the decimal number(00 = 0 to FF = 255) so instead of going 1,2,3,4,5,6,7,8,9 then 10 you go 0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f then 10.

And real quick on the subject of HEX if you are familiar with hex colors like 000000 = black and ffffff = white that is just three hex numbers to represent RGB so 00FF00 is green and 0000FF is blue, etc.