bytebug@dhw68k.cts.com (Roger L. Long) (05/29/88)
[187: Don't Look at ioPosOffset]
The Device Manager chapter of Inside Macintosh Volume II says
that ioPosOffset is passed to and returned by Read and Write
calls. It also says that "After the read [or write] is
completed, the position is returned in ioPosOffset..." Actually,
ioPosOffset is not changed by either call.
Also note that device drivers should only look at the
dCtlPosition field of the DCE, and should not look directly at
the ioPosOffset field of the parameter block. The Device Manager
sets up dCtlPosition for the driver, taking into account both the
ioPosMode and the ioPosOffset.
---
(This file must be converted with BinHex 4.0)
:$c%i0b"TEe"[FdpQCR0PG!"A6e*%68&$33#3"!HU!!!$%BEp!!B!$J!#!!-!N!2
r!2rrr!!"!!!(SJ!)!!J!!!I-!!J!#!!!$AB!%!!#!*!$5!")!*!%!YS#+2rKrq)
#q3*'!`F&+!2m!!)!N!0)!%J!N!3#fJ)S!!%!N!0N!*!$!3!"N!-!N!-"*`m!!3!
"!!)i@!!#11$rr`#3"4N"N!!!N#%#!$d!!J!p!*!$!3!!"GS!-!!!"FS!%!!-!1h
rmJ"qrr)"52q3#J!"!*!$!3#3"3%!!!B5!#!!!!B+!!MrmJ!Hrr)!l2rb!EVrN!S
!!3#3!`%!N!8"!!!'`J$J!!!'-J#3!2rb!"lrmJ$Xrr)"Z[q3"3!*!!!9!!m!+!!
[!!N"l`!#!*!$#3$6rKm"l`([CA)JDA-JC(*KCfGTEL!JG!!"$@8!"J!!#J!!&3!
pp8(,0mDJp18K$b2c(cMcI`RQpR%!N!-&d2-I#I4&2p8Jp-9ID`BJGI8&MdrGJ5!
!!!B!!!S!!"8!#3(K!!%!N!-*!@J'J!#3&`B!!!`!!!-!#3(Q!`3!N!-*!#J!H3%
r!Fm#%!)3EL"TFb"KEQ&XEfG[!'"IN&m0!!B!!!N!!"8!(I6@ac*BX29"bcI'S26
P)Bm*m*r`m0!!$!!!$J%!&3!E'"%!&`!"$@8!"J!!$J!!&3!JmMmamimhmk$d46r
9)26&AfX')(Ae"Bp2hB%[$3!'!!!1!!!9!!%0r`!'!!!1!!!9!"he-4"UKI1[#I9
,%24"pfI"$deMEfF8m0!!"J!!$J!!&3!"$3%!"J!!$J!!&3!QpA4b)6$f,hRcV`R
d4NF`p"QK6`Rd(NHJmbmX$c(cRcMcM`d!!!B!!!i!!"8!B&q3A`d!"J!!#3!!&3!
"$3!!"J!!$J!!&3%@p"U&!e)3+f)*(hCm%*4rGK5!LepeU38kpj!!T9pV"L!V%*p
$+[8&KbG6$A'T"G!V%2423r4I,!Bj#,Ah@T!!05#PAfX*G"`Upj!!BJ+a"ep3@26
pf")0FDN&d#X3jNEfd5&!pLTFpVmZ$e5a$d3IGR`3p0BfpR&!J5J2GH#I3bVe"BF
R8`e8!V%*4rGK6b`#EfYcpR"c*3E-Ah8b$f*5X#X3GI8&MdeC%'13!#X3GI8&Mdr
GJ5mZ!!"1!!!-!!!9!#8-!3!9!#N-!!!9!$B-!!!@!%)-!!!9!(N-!!!@!)3-!!!
9!,i-!!!@!-S-!!!9!2J-!!!@!3%-!!!9!3S-!!!@!48-!!!9!!%0"J!'!!!-!!!
9!4ce5a$d3IGR`3p0BfpR&!bfiK3&d256Kj%26@ac*BX29PVhAfd3p*p*#'pjJ#Y
L"ep3@26pf")(J1D)'3*3Bj!!35pe3aN2B[H3!28KD3Bj$eG()3aUU2,Jp*)'U&#
'pjJ#YL$p,d(5&!+a""D3!2@e32GdFKpG"i$&pYkK)CmX!V%1@(*e-(J%%[G8-C!
!F`GI8&MdrGJ5r*r6$d(#peDUpjmX"ep3@26pf")(J$8Jbf2fFC!!pLpj!A+a3-D
UmZm0!()!!!`!!"8!(J`#!"8!1!`!!"8!3``!!"B!6J`!!"8!A!`"!"8!A``!!"8
!B!`"!"8!D!`!!"8!D3`"!"8!D``!!"8!E!`!!"B!F!`!!"8!G3`!!"B!HJ`!!"8
!f3`!!"B!j!`!!"8!m3`!!"B!r!`!!"8!N!-"$!`!!3`-!*!,&*c))!!"-!!L!*!
$$!#3!a5G)#!!!9)!$$)"!!`!$!!6IMJS!!&H!$Sb!3#3!`%3%!#3"a5G"#!!!CJ
!)J#3!a!!N!-6IN`J!!'k!!SV!3#3!`%,#`!"("`!!3m2!!%2$`!"$`m!!3m2!!%
2$`!"$`m!!3X,!!%2$`!#$S3!!3i1!!)1K!#3Aa0q+#!!!F3!)J#3!`X!N!-8&6!
J!!(Q!'Sa!3!F!!X!&"3)+!!#8!!Q!!)!$`!R!"36p#!!!RB!$$3"!!m!0J!6IL!
S!!+#!#Bd!3!2!%8!%hh`)!!#U!!-0!%!$`"8!"36H#J!!V3!)M3"!!m!B`!8R6!
J!!,@!!`d!3!2!()!%hhS+!!#iJ!Z0!%!#`#"!"0q%#!!!a!!DM%"!!m!M!!8&,3
J!!0k!!`d!3!i!*X!&"2J+!!%Q!%b!`!!$J$6!"5G1#!!")`!$$-"!$J!i3!8&+J
S!!1'!3B$!*!$"kS!3F!UP68!!!%!N!-#X`!!!E-!N!0HEQ4[Gb`*#5#3"AYcG'p
bCA-JG'KP)(GTEQ4[Ge"d$c%i0b"TEe"[FdpQCR0PG!)!N!0A6e*%68&$33#3"PG
28N40380"!*!&l3#3%!S+0G(bIJ!!"kS!!!-4Eh)JG'KP)%&`F'aTBbiJC(9bD@j
R)(9`C'&dCA0p$5!J4'PbC@0dEh*j)$SJ9fPZC'ph8(4b1`NJN!9l9fPZC'ph)'C
[FL"NC@CKG@ad)'4TFfXJC'PbC@0dEh*jI3d0)#"cBh*PC@iX#C!$)*!&Hh*PBh4
KEQGXC5"dD'&d!!!"6!C6G@jNBAN!N!N'6@pZC'&j!*!*"e4eCA0NBAN!N!J*9f9
NEQ9cC'&j!*!'#&4SGA*cC'&j!*!("NCbD@4KH3#3#3K6BA4eFQ4KH3#3"`G+B@j
eBA*j!*!)#%CPBR*eBA*j!*!("8eKFQ0S!*!+"8&`FQPX!*!+!deKH3#3$!4+G@j
P!*!,"%TeE(N!N!X'3A9RGA0d!*!*#90PF(4PE@*PFJ#3"JG2Bh4[BQ9b!*!)#%j
[GQ9YBQ9b!*!(#%4PBf9YBQ9b!*!(rrm!!`#3"#`J!!!J!*!$,#!!N!F"6R8!N!-
B!!X!&`!@!"8!&!#3!`-!!J!%!!8!"J!(!*!$%!mJCA4ZFQpKDA0NE'KMCR!!N!-
[!!m!"`!,!*!$&J!$!"8!"J!-!"J!"!!#!!J!&`!8!!83%!3rN!-3*"!&2a!r2`J
!!!%!N!-#X`!!!E-!N!0H!"0qf!X'!*!$(!"H!!&*6P4-!*!$%P088L!!!J!H$YM
rrb!!N!F$)2rr!!!"8!#3"!+mrrm!!!&X!*!%!b(rr`!!!B!!&*eX"U):
---