One of the changes on version 7 is moving global functions into their respective structs.
In this case, try
disp_buf1.init(buf1_1, None, len(buf1_1)//4)
One of the changes on version 7 is moving global functions into their respective structs.
In this case, try
disp_buf1.init(buf1_1, None, len(buf1_1)//4)