🚀 go-pugleaf

To: fj.sys.misc
Subject: Parity Sector? FD error correction.

720KB, 1440KB $BJ}<0$N(J 3.5" Floppy $B$O(J 1 track = 9 sector $B$J$N$G(J,$BNc$($P(J
$B$3$l$r(J 8 sector $B$H(J 1 sector $B$K$o$1(J, 1 sector $BJ,$r(J parity sector $B$H$9$k(J
$B$h$&$J5-O?7A<0$r(J User program Level $B$G:n$l$P(J,$BMFNL$O8:$k$1$I(J
$B%(%i!<$d=}$K$bB?>/4h>f$J5-O?$,=PMh$k$H;W$&(J. ($B8D?ME*7P83$+$i$O(J, 
3.5inch $B$O(J 5inch $B$d(J tape $B$K3S$Y$F05E]E*$K5-O?$NJ]B8$K4h>f$5$,$J$$$7(J,
$B%W%i%9%F%#%/%8%c%1%C%H(J,$B%A%c%C%-%s%0$N@:EY$K6KEY$KIR46$G$"$k$H;W$&(J.)

    1 2 3 4 5 6 7 8 9
 1  = = = = = = = = P
    = = = = = = = = P
	  . .
	  . .
	  . .
    = = = = = = = = P
80  = = = = = = = = P

$B$G$b$3$l$G$O0l$D$N%H%i%C%/>e(J, $BFs$D$N%;%/%?!<$K%(%i!<$,$"$k$HBLL\$@(J.
$BFC$K(J, $BJ*M}E*$KNY$j9g$&%;%/%?!<$K$^$?$,$C$F=}$,F~$C$?$i%"%&%H(J.
$B$3$l$rHr$1$k$K$O(J, $B%;%/%?!<$N=gHV$rF~$lBX$($F(J,$BO@M}>eNY$j9g$&%;%/%?!<$,(J
$BJ*M}E*$KNY$j9g$o$;$K$J$i$J$$$h$&$K$9$l$P$h$$(J.

$B$3$N$[$+$b$C$H9bEY$J8m$jD{@5$N??;w;v$r$9$l$P(J,$BNc$($P(J
$BH>J,6a$/$N%;%/%?!<$K%(%i!<$,$*$-$F$bBg>fIW$H$9$k$J$I$N$3$H$,=PMh$k(J.

($B$3$N$h$&$J%W%m%0%i%`$,=q$1$k$@$m$&$+(J.  $B%W%m%0%i%`$+$i(Jsector error $B$,(J
 $B5/$3$C$?$i$=$N%;%/%?!<$rHt$P$7$FFI$a$k$N$@$m$&$+(J? )

$BDI2C(J.

Floppy disk $B$N(J sector $B<+?H$O(J ECC $B$r%O!<%I%l%Y%k$G;}$C$F$k$O$:$@$,(J,

ECC $B$K0M$kD{@5$,(J

	1) $B9T$J$o$l$?$+$I$&$+(J,
	2) sector$BCf(J $B2?%S%C%H$N(J Error $BD{@5$r9T$J$C$?$+(J

$B$J$I$r(J,$B%f!<%6!<$N%W%m%0%i%`$+$iCN$kJ}K!$O$J$$$N$@$m$&$+(J? (device driver 
$B$K$OJ,$+$k$N$+(J? $B$=$l$H$b(J SCSI $B$,1#$7$F$$$FJ,$+$i$J$$(J?)

Format $B$7$?CJ3,$G$O(J, sector $BCf$K(J Error $BD{@5$rI,MW$H$9$k0-$$%S%C%H$O(J
$B$J$+$C$?$3$H$,J]>Z$5$l$F$$$k$N$@$m$&$+(J? 
($B$=$l$H$b(J,$BD{@55!G=$N5vMFHO0O$NITNI%S%C%H$OMFG'$5$l$F$$$k$N$+(J?)

Error $BD{@55!G=$NF0:n$,8+$($l$P(J, $BD{@55!G=$K$h$j$+$m$&$8$F@5>oFI=q$-$,(J
$B=PMh$k>uBV$J$i(J, $B>e=q$-$7$FD{@5$r;n$_$k$+(J, $BNIIJ$K=q$-0\$9$3$H$G(J
$BFI$a$J$/$J$k4m81$r2sHr$G$-$k$N$@$,(J. $B$^$?(J, media $B$NITNI6q9g$r(J
$B8!::$b=PMh$k$N$@$,(J....

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                         $BJbJbJbJbJbJbJbJbJb(J              $BB<>e(J	$B90(J
PPPPPPPP                   $B3Q(J          $BHt(J
RNBQKBNR                 $B9a7K6d6b6L6b6d7K9a(J   mhiroshi@tansei.cc.u-tokyo.ac.jp