Contents of the ROMU.DOC file
DESCRIPTION: A simple utility to create and maintain AT ROM image
files including disk table and checksum changes.
CONTACT: Keith P. Graham at PC Rockland BBS (914) 353-2157
USAGE: ROMU.COM is initiated by entering ROMU at the dos
prompt. ROMU has 3 menus.
MENU 1. This menu provides several choices for a source of
ROM data. The source can be the current AT ROM, or
a file or files created by ROMU or similar utility.
The source of data can be either 32K (27128 type ROMS)
or 64k (27256 type ROMS). If loading information from
a file, the data can be a complete BIOS image or a
split image which corresponds to the high and low ROM
MENU 2. After a source is selected it is possible to display
and alter the disk table, calculate the checksum or
force the checksum to 0. A 32K ROM image can be
be converted to 64K by padding the low 32k with zeroes.
The file can be written out as either a BIOS image
or two split rom images.
MENU 3. This menu is shown when the the user chooses to display
and modify the disk table entries. The normal disk
table address in an AT is fixed at f000:e401. ROMU
makes the assumption that this address holds true for
all AT roms. IBM AT's have only 15 table entries which
can be changed. Some AT clones and 386 clones have up
to 64 table entries. ROMU will display all 64 entries
even if they are not valid. The invalid entries will
have odd characters while the valid entries will have
only decimal characters. Do not change entires beyond
the known limit of your bios.
When changing an entry you will be shown the current
value and asked for a replacement. If you press the
return without making an entry the existing entry will
be used by default.
When you have finished making all entries for a disk type
you will be shown the table entry and asked if it is
acceptable. If you enter "Y" the bios image will be
NOTE: There was a type in the source of the first ROMU I
sent up which broke the reading of split files and the
writing of 64k files. Its fixed now.