Changes between Version 12 and Version 13 of FuzixBuildNotes

Timestamp:

Nov 24, 2020, 8:51:49 PM (5 years ago)

Author:

Eric Hazen

Comment:

--

FuzixBuildNotes

@@ -105 +105 @@
 Hangs after that, but it seems control is being passed to the kernel from the boot loader and thus to init.
 
+Time to read the boot loader.  Sigh.  Here's some interesting stuff about the boot disk:
 
+{{{
+;       Floppy loader: 
+;       Our boot disc is 77 tracks of 26 x 128 byte sectors, and we put
+;       the OS on tracks 58+, which means we can put a file system in the
+;       usual place providing its a bit smaller than a whole disc.
+}}}
+
+77 * 26 * 128 = 256256 - that's the size of e.g. {{{diska.cpm}}}.  Bingo.
+
+Check the OS offset:  193024 = 58 * 26 * 128.  Or 0x2f200.
+
+Dump some of my disk image (after the dd) and I do see the start of fuzix.bin
+at 0x2f200.  But interestingly not in the old {{{fuzix.dsk}}} supplied with z80pack.
+There, the kernel starts at 0x30c00, which is track 60, not track 58.  Hmm...
 
 '''2020-11-22'''