ef238e6ab90d807a28fc144fa520b50c0d1b9801 mspeir Mon Nov 3 17:12:17 2025 -0800 changing genome-source to github references, refs #35031 diff --git src/hg/htdocs/FAQ/FAQformat.html src/hg/htdocs/FAQ/FAQformat.html index 3458da4e761..5197a05cb95 100755 --- src/hg/htdocs/FAQ/FAQformat.html +++ src/hg/htdocs/FAQ/FAQformat.html @@ -935,31 +935,31 @@
  • maskBlockStarts - an array of length maskBlockCount of 32 bit integers indicating the (0-based) starting position of a masked block
  • maskBlockSizes - an array of length maskBlockCount of 32 bit integers indicating the length of a masked block
  • reserved - always zero for now
  • packedDna - the DNA packed to two bits per base, represented as so: T - 00, C - 01, A - 10, G - 11. The first base is in the most significant 2-bit byte; the last base is in the least significant 2 bits. For example, the sequence TCAG is represented as 00011011.
  • For a complete definition of all fields in the twoBit format, see -this +this description in the source code. Click these links to see examples of using the faToTwoBit, twoBitInfo, and twoBitToFa commands, and how to extract DNA from 2bit files, including with our API.

    .nib format

    The .nib format pre-dates the .2bit format and is less compact. It describes a DNA sequence by packing two bases into each byte. Each .nib file contains only a single sequence. The file begins with a 32-bit signature that is 0x6BE93D3A in the architecture of the machine that created the file (or possibly a byte-swapped version of the same number on another machine). This is followed by a 32-bit number in the same format that describes the number of bases in the file. Next, the bases themselves are listed, packed two bases to the byte. The first base is packed in the high-order 4