Re: Addon for the documentation and booting 286

[Bernhard Grill <grl@titan.e-technik.uni-erlangen.de>]

I just want to add a comment to the following :

> Some cards  can be run  both in NE2000 and WD80x3 mode;
> these cards  have   been reported to  not   map any   EPROM data  when
> configured in WD80x3 compatibility mode.

I have such a card (with the the National Semiconductor DP83905
AT/LANTIC chip), which can be operated in two modes. Looking at the
data sheets, which can be found at
http://www.national.com/pf/DP/DP83905.html I could figure out the
following:

The size of the boot PROM is depending on the card's mode.

Configured as NE-2000 the AT/LANTIC chip supports 8k or 32k or 64k byte ROMS.
In shared memory (WD-mode) it either supports 16k or 32k or 64 k byte ROMS.

However, on the two models of cards using this chip I have, the 32k
and 64k options seem not to be available. In I/O (NE-2000) mode 8k
PROMS and in shared memory (WD) mode 16k PROMS seem to work.

I write seem to work, since I havn't been completely succesful yet.

The boot process is initiated by the prom. The IP address message
appears and the loading of a tagged file is reported. However, the
spinning bar (probably showing the loading of the boot file) stops
spinning after two or three seconds, and nothing more happens.

I'm trying to boot DOS on a 286 with 640 + 384 kbyte of RAM. I have
seen several emails regarding the booting of a 286 on this reflector,
but I couldn't get a clear picture yet.

The boot Image I'm using was compiled with mknbi-dos from a directory
just containing io.sys msdos.sys and command.com.


Bernhard Grill                           email: grl@lte.e-technik.uni-erlangen.de
Lehrstuhl fuer Technische Elektronik     phone: +49 9131 857200
Cauerstr. 9, D-91058 Erlangen, Germany   FAX:   +49 9131 302951


-----------------------------
output of mknbi-dos below:

io:/amd/europa/sw/net/etherboot-3.1> netboot/mknbi-dos/mknbi -r dos6 -x -x
-x -f -o dos6.image
Using directory dos6 to create ramdisk image
Scanning directory tree
Generating FATs
Writing temporary ramdisk image file
Ramdisk filename = dos6
Output file name = dos6.image

Load record information:
  Magic number:     0x1B031336
  Length of header: 16 bytes (standard) + 16 bytes (vendor)
  Flags:            0x00000000
  Location address: 1000:0000
  Execute address:  1040:0000
  Vendor data:      GK-mknbi-DOS

Record #1:
  Length of header: 16 bytes (standard) + 0 bytes (vendor)
  Vendor tag:       0x10 (primary boot loader)
  Reserved flags:   0x00
  Flags:            0x00 (absolute address)
  Load address:     0x00010400
  Image length:     0x00000E00 bytes
  Memory length:    0x0000FC00 bytes
  Vendor data:      none

Record #2:
  Length of header: 16 bytes (standard) + 8 bytes (vendor)
  Vendor tag:       0x11 (ramdisk image)
  Reserved flags:   0x00
  Flags:            0x04 (absolute address, last record)
  Load address:     0x00110000 (high memory)
  Image length:     0x00033200 bytes
  Memory length:    0x00168000 bytes
  Vendor data:      80 cylinders; 2 heads; 18 sectors; disk id: 0x00

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