Path: utzoo!attcan!uunet!mcvax!kth!sunic!kullmar!pkmab!ske
From: ske@pkmab.se (Kristoffer Eriksson)
Newsgroups: comp.sys.ibm.pc
Subject: DOS and Xenix on separate hard disks on the same system
Message-ID: <1479@pkmab.se>
Date: 25 Jul 89 20:00:29 GMT
Organization: Peridot Konsult i Mellansverige AB, Oerebro, Sweden
Lines: 82

In article <1282@pkmab.se>, about a month ago, I wrote:
>On my system (Xenix/386 2.3), I have patched the "dos" boot program to
>load DOS from the second hard disk. I have Xenix on the entire first hard
>disk, and DOS on the entire second hard disk.

I got two request by mail for my patched "dos" program. I have tried replying
by mail, but both addresses just bounced. So now I try posting it here. It's
short.

This is the uuencoded binary of my patched "/dos":

table
 !"#$%&'()*+,-./0123456789:;<=>?
@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_
begin 400 dos
M!@(L #D!  !H    "                    $1D!\P                 z
M       ! &    !                   $"/P                      y
M         0 (@#\   "@    .0$  #D!                   "  2 1P  x
M -D!  !H    <                    /JC70")/E\ B0YA (S8CM"\\/_[w
MQ!YC +J! ;D! +\% + !M +-$W,)3W9PM #-$^OO^K[^?2:!/%6J= B^00#Hv
M@P#K2;Z^?2O;*_^Y!  F@#R =0*+WB: ? 0!= <F@'P$!'4"B_Z#QA#BXPO_u
M=0B0D)"0D)"0D+O]?9 FQ@>!D)"0D.A2 .AM /\N8P",V([ H5T CM@F_RY?t
M (S?CL>_(@#H" "^$ #H&@#K_E.[  "*Q-#HT.C0Z-#HUZJ*Q"0/UZI;PU-0s
MLP?\K K = :T#LT0Z_186\-245-06"O)ND\8MP<JP+0&S1 KTBK_M +-$%M9r
M6L-345)75@8>,\".V+\3!/\-BP6Q!M/@CL"_  "[! $SP([8Q3>)/XQ' KD0q
M /SSI('[! %U!;L8 >OD'P=>7UI96\,P,3(S-#4V-S@Y04)#1$5&#0ID;W,Zp
M(')E860@97)R;W(@6%@-"@ -"F1O<SH@;F\@9&]S('!A<G1I=&EO;@T*  T*o
E9&]S.B!N;R!P87)T:71I;VX@=&%B;&4-"@          ?    &EOn
 m
end

I have no source. I just disassembled the original program, and picked out
convinient spots to patch. If someone really needs to know how it works, I
probably could find my notes somewhere.

These are the bytes I've changed (cmp -l), in case it helps someone:

  original  new
        !   !
   186 200 201
   187   0   1
   273 276 220
   274  47 220
   275   0 220
   276 350 220
   277 120 220
   278   0 220
   279 353 220
   280  26 220
   281  13 273
   282 333 375
   283 164 175
   284   4 220
   288   0 201
   289  46 220
   290 306 220
   291   5 220
   292 200 220

There is no guarantee whatsoever that this will work on any system but mine.
This program itself makes some in-core patches to other routines and tables
that it loads while booting, since otherwise the MSDOS boot sector wants to
boot from the first hard drive only. That of course makes my patches dependent
on the MSDOS boot sector layout, among other things.

But it DOES work wonderfully on my system, and has no ill effects.

---
mtuxo!rayii: You didn't supply any return address for me at all. There even
wasn't any From:-header. All addresses I guessed at from the Received:-headers
just bounced from rutgers.edu.

brian@alzabo (Brian Hilchie): Maybe you did get my reply. But I haven't got
any confirmation from you (like saying "Thanks"). One address I tried bounced
from mitel (the one in your signature). Another one just disappeared
("brian@alzabo", wich lacks the top-level domain).

Maybe you could try mailing me better addresses, if you like.
-- 
Kristoffer Eriksson, Peridot Konsult AB, Hagagatan 6, S-703 40 Oerebro, Sweden
Phone: +46 19-13 03 60  !  e-mail: ske@pkmab.se
Fax:   +46 19-11 51 03  !  or ...!{uunet,mcvax}!sunic.sunet.se!kullmar!pkmab!ske