1. ...me again
- Posted by Hayden McKay <hmck1 at dodo.com.au>
May 04, 2007
-
Last edited May 05, 2007
Hayden McKay wrote:
> > Another issue is that sometimes dos_interrupt() returns bogus results as
> > in sighned words & unsighned dwords, the return sequence should be words
> > eh? if you scroll down and comment out the line
> >
> > }}}
<eucode>
> > dpmi = and_bits(dpmi,#FFFF) -- patch bogus result
> > </eucode>
{{{
> >
> > loop is broken completly cause 'dos_interrupt()' return a sighned dword
> > note that causeway v3.45 supports dword dos interrupts although the old
> > causeway wrapped with eu v2.4 sometimes return theese bogus result too?
> >
I found the problem to be with the line
dpmi = repeat(-1,REG_LIST_SIZE)
-- it should read
dpmi = repeat(NULL,REG_LIST_SIZE)
It seems as though I left my brain in bed...lol
here is the source code again with fixups...
include euphoria.e
sequence dpmi -- dpmi structure
dpmi = repeat(NULL,REG_LIST_SIZE)
-- check for the drive a: geometry
dpmi[REG_ES] = NULL
dpmi[REG_DI] = NULL
dpmi[REG_DX] = NULL
dpmi[REG_AX] = 8 * 256
dpmi = dos_interrupt(#13,dpmi)
-- dpmi = and_bits(dpmi,#FFFF) -- patch bogus result
constant fn = open("fdd.img","wb")
constant S = and_bits(dpmi[REG_CX],#3F)
atom cache
cache = allocate_low(S * 512 + 4)
cache += 4-remainder(cache,4) -- align(4)
atom t t = time()
for C = NULL to floor(dpmi[REG_CX]/256) by 1 do
for H = NULL to floor(dpmi[REG_DX]/256) by 1 do
-- docs state that you should have at least three
-- io attempts if failed, but i assume the bios's
-- fdd handler will do that too...?
mem_set(cache,#4E,S*512)
dpmi[REG_DX] = NULL
dpmi[REG_AX] = NULL
dpmi = dos_interrupt(#13,dpmi) -- recalibrate fdd
dpmi[REG_ES] = floor (cache/16)
dpmi[REG_BX] = and_bits(cache,15)
dpmi[REG_DX] = or_bits(H * 256,0) -- {head,drive}
dpmi[REG_CX] = or_bits(C * 256,1) -- {cyld,start}
dpmi[REG_AX] = or_bits(2 * 256,S) -- {func,count}
dpmi = dos_interrupt(#13,dpmi) -- get fdd sectors
-- dpmi[REG_DX] = NULL -- broke inner loop
-- dpmi[REG_AX] = 1 * 256
-- dpmi = dos_interrupt(#13,dpmi)
-- dpmi[REG_CX] = NULL -- but not brake outer loop
? {C,H}
puts(fn,peek({cache,S*512})) -- flush the cache
end for
end for
t = time() - t
printf(1,"%d secs\n",floor(t))
close(fn)
abort(NULL)
