A vast increase in running speed can be obtained when using programs written in assembly language, which in essence entails direct programming of the computer without using a high level built-in language such as BASIC. However, this can only be undertaken by someone who has a reasonable understanding of the microprocessor and some of the other hardware used in the computer, but it is not as difficult as one might think and this book tells the story
Teach Yourself 68000 Assembly Language Programming