Hi Grant, The tapes are comprised of recorded ascii data (s-record format) ...so if you are just reading the data as is (vs. loading the data via a s-record loader) then you should probably get the same thing regardless if you use 7 or 8 bits. I assume that you are referring to the data in memory as a result of the ROM tape loader execution? If so, you will note that Basic has bit 8 set on many ascii text elements within the source. Microsoft Basic used the high bit set in the keyword tables for the code that searched the keyword tables. They also often used the high bit to determine the last character of message strings. It appears that the tape is similar to the MITS Absolute Tape Load format. I'm guessing that your format is as follows: First ... Pre-leader - comprised of a series of bytes that represent the length of the tape checksum loader. For example, a series of 7F bytes would mean that the checksum loader is 127 bytes long. Second... S-record header record (S0) Third... Checksum loader - intended for those who do not have the kacr ROM. It should be 127 bytes in in your example. Forth... Tape leader - a series of nulls Forth... The actual code. There may be some garbage bytes appended, depending on how MITS dumped the tape (specifically, how long the address range specified to dump was). Fifth... Trailer - a series of nulls This is similar to the typical format used for MITS tapes (both paper and cassette based). Scott __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com