path: root/diag
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authorGene Cumm <gene.cumm@gmail.com>2015-02-15 11:01:20 -0500
committerGene Cumm <gene.cumm@gmail.com>2015-02-15 11:01:20 -0500
commit9efca14a13d535551a8e5f5e7475b77b6a2c166e (patch)
tree2bf342af0b7cb2cec9f2905cebea3e6e160f3ceb /diag
parent69cd07642a7d95265888f670f8d050f1ddf3ab01 (diff)
diag/geodsp: Update README with a sample
Signed-off-by: Gene Cumm <gene.cumm@gmail.com>
Diffstat (limited to 'diag')
1 files changed, 24 insertions, 0 deletions
diff --git a/diag/geodsp/README b/diag/geodsp/README
index 9129b694..4539106d 100644
--- a/diag/geodsp/README
+++ b/diag/geodsp/README
@@ -27,3 +27,27 @@ majority of the BIOS parameter block).
dd bs=1 skip=3 count=87 if=/dev/fd0 of=fd0.bpb
dd conv=notrunc if=geodspms.img of=/dev/fd0
dd conv=notrunc bs=1 seek=3 count=87 if=fd0.bpb of=/dev/fd0
+Sample output:
+ CHS 0081,FE,3F
+ @CHS 0000,01,01:0000003F
+ @CHS 0001,00,01:00003EC1
+ @EDD 0000003F:0000003E
+ @EDD 00003EC1:00003EC1
+ end
+The first line is the interpreted geometry per INT 13h AH=08h,DI=00h (in
+hex). The second line is the data value at the sector CHS 0,1,1
+(indicating effective sectors per track). The third line is the data
+value at CHS 1,0,1 (indicating effective heads per head count). The
+fourth line indicates the value read at LBA 63. The fifth line
+indicates the value read at LBA 16065. The sixth line indicates the
+final expected mode.
+Images created by the Perl variant up to and including 6.03 are off by
+one and shifted by one byte. In the above, the second line might read
+"00003E00" instead of "0000003F".