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Old 07 May 2022, 20:55   #3
Rock'n Roll
German Translator

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Join Date: Aug 2018
Location: Drübeck / Germany
Age: 47
Posts: 64
I try to understand:

first line:
DSKLEN: - info label, like SYNC:
drive 0 - ok, it's df0:
motor on - motor state
cylinder 0 - track 0, side 0 (info)
sel yes rw - ?
mfmpos 52533/101344 - ok, current bit position

total length: 101344?
1 track = 11*512 Bytes*8= 45056 Bits
MFM=11*(2*(64Byte+512Byte))*8=101376 Bits

second line:
data - 17 words, mfm data (but not synchronized)
data are not from the beginning of a track?
the current position stands anywhere? like here: 52533?
(Then a breakpoint for a certain mfmpos would be good?
To analyze mfm-data from beginning of a track)

| = current position - ok, from the raw bit stream dump

third line:
side 0 - ok, see cylinder 0
dma 2 - ? dma is always 2?
off 1 - ? off with different numbers from 1 to 13?
word 5555 - ok, current value
pt 00002064 - DSK pointer ($dff020,22 DSKPTH, DSKPTL)
len 9CBE - ok, length ($dff024 DSKLEN)
bytr 80AA - ok, DSKBYTR ($dff01A DSKBYTR)
adk 1100 - ok, ADKCON ($dff010 ADKCONR)
sync 0000 - ok, DSKSYNC ($dff07E DSKSYNC)

SYNC: drive 0 motor on cylinder 69 sel yes rw mfmpos 5648/101344
AAAA AAAA AAAA 4489|4489 5545 2AA5 552A AAA9 2AAA AAAA AAAA AAAA AAAA AAAA AAAA AAAA
side 0 dma 2 off 0 word 4489 pt 00070000 len 9F40 bytr 8044 adk 1500 sync 4489

What means SYNC?
It's this preamble and syncword? AAAA AAAA 4489|4489
But why there are three times AAAA AAAA AAAA and not only 2 times?
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