- 8 bit char mean the available bits to store one char is 8-bit, The character encoding is 8 bit US ASCII==> mean just the chars that is in the ASCII so there are no arabic or another language just english, - null terminated ==> if the field have the value "mohamed" in the location so the the field in the db will be "mohamed " and the empty string is null or '\0' or the byte "00000000" is an null char. so in the above ex there are 64- len("mohamed") = 57 null bytes after mohamed.
Even if you had searched at Google about the 8 bit US-ASCII encoding, you would still have doubts about it, as it is a 7 bit character encoding, not 8. It means that you have to read/right records from the databae using this character encoding. For instance, when I read records from the database, I create Strings with each byte array that corresponds to one field value, using this encoding (new String(byte array, "US-ASCII")). You may still use it, even though it is a 7 bit character encoding. I justified that I used it anyway, even though the specifications refer to it wrongly.
About the null terminators, I did not use them. I added extra spaces to the value of each field, so it has the maximum size of its position. For instance, a field can have 64 characters, and the value has 30, so the value that will be persisted is 30 + 34 blank spaces.
Payal, please feel free to come here and ask any question you want. Someone will indeed help you!