Hi John,

> - This concerns SHARE installed by CBIS Desk-To-Desk (not FreeDOS SHARE), 
> temporarily available at [...]
> - Testing still failed with HIMEM and EMM386 not loaded...

I ran your SHARE in DOSEMU. It indeed insists that the
DOS version is 6.22, and it does something bad:

0439:0adb B452             mov     ah,0x52
0439:0add CD21             int     0x21
0439:0adf 26C6060303FF     mov     es:[0303],0xff
0439:0ae5 FA               cli
0439:0ae6 BE0C0A           mov     si,0a0c
0439:0ae9 BF9000           mov     di,0090
0439:0aec B91E00           mov     cx,001e
0439:0aef F3A5             repe    movsw
0439:0af1 26833E440000     cmp     es:[0044],0000
0439:0af7 754F             jne     0b48

In other words, it asks DOS for the location of some
internal data structure, then ignores the exact
location, and uses the memory block which contains
the data structure to as a target for overwriting
1 plus 60 bytes of data. In short, your SHARE modifies
the DOS kernel, because it believes that it knows
what it is doing. This will work with no other kernel
except the MS DOS 6.22 one... I wonder why the author
of that SHARE made it so limited. I mean it will not
even work with any other version of MS DOS...

FreeDOS crashes at the first time when SHARE asks
the DOS kernel to do anything useful after that,
because SHARE has overwritten parts of the kernel.


Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
Freedos-user mailing list

Reply via email to