Re: int 0x13 utility

On Sat, 29 Mar 2008 14:36:11 +0000, =?UTF-8?B?Sm/Do28gSmVyw7NuaW1v?=
<spamtrap@xxxxxxxxxx> wrote:

Dirk Wolfgang Glomp wrote:
But if you write your own HD-driver, the physical CHS-limit is:
16 heads, 255 sectors, 65536 tracks(cylinders), and this gives
us 267386880 sectors (= 127.5 GB).
So if the the hardware can handle it then it works almost like LBA28
(max= 128 GB), ...except for the unconvenient calculation needs.
But is this a DOS or a BIOS level driver?

If you write the driver for DOS it´s a DOS-driver, else if you write
it for your own OS maybe you can call it BIOS-driver?

Nop. But I don't know whether DOS can have it's own drivers to control HDs.
DOS usually calls the BIOS, so one can replace the BIOS HD driver and have
DOS call it, thinking it's the original BIOS driver.

Did you understand, or need more explaining?

JJ


If you replace the INT 13h vector with a vector to your own
handler, you would effectively have a "DOS driver". I have done this
long ago for a different reason than drive size: The DOS INT 13h shut
off all interrupts during transfers to disk, but I needed to respond
to A/D sample interrupts on non-DMA data acquisition systems,
in order to allow Direct-to-Disk recording. My INT 13h was pretty
much an ordinary CHS type, except it allowed the sample interrupts to
pass through during the block moves. Worked great: There was no
problem with sample rates of more than 100 kHz. Above about 120 kHz
the sample timing was adversely affected, so I never tried to go
higher to see if or when disk transfers might have suffered.

Best regards,


Bob Masta

DAQARTA v3.50
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, FREE Signal Generator
Science with your sound card!

.

Relevant Pages

  • Re: Found, a new rootkit
    ... I fail the see the difference between the Linux driver for a serial ... The drivers themselves simply make BIOS calls. ... part of DOS< and not a BIOS setting. ...
    (Fedora)
  • Re: int 0x13 utility
    ... 16 heads, 255 sectors, 65536 tracks, and this gives ... But is this a DOS or a BIOS level driver? ...
    (comp.lang.asm.x86)
  • DAC960M errata (applies to Passplay)
    ... The BIOS provides access for up to 8 system drives per DAC960. ... total DOS partition size is limited to 1024 cylinders (this is a BIOS ... Windows, QEMM etc., a DOS driver needs to be used. ...
    (comp.sys.ibm.ps2.hardware)
  • Re: Getting DOS screen to full screen ....
    ... They had the right mix of ports ... Mine however refuses to expand the DOS display to full screen, ... BIOS setup screen. ... Some laptops require a driver to make the display full screen I think, if it isn't in the BIOS or a Fn key. ...
    (alt.sys.pc-clone.dell)
  • Re: Maybe we should stop "Paging Beth Stone" already...
    ... | PIT because that's what DOS uses, and of course DOS uses it because it had ... Driver development is a story on its own, ... | xor dword ecx, ecx ... | mov dword edx, VGA_PEL_INDEX_READ ...
    (alt.lang.asm)