

This is one of a few revisions of motherboard BIOS for the IBM 5170 (IBM AT).
This revision is dated 10JAN84 (01/10/84).

This is the 2-ROM version of the 10JAN84 revision BIOS, where each ROM is of type 27256 (or 27C256).


+---------------------------------+
|  GENERAL                        |
+---------------------------------+

ROM chip U27 has the IBM part number of 6181028, and is 32K in size
ROM chip U47 has the IBM part number of 6181029, and is 32K in size


8 bit checksum of 6181028 = 36
8 bit checksum of 6181029 = CA
                           ----
                    added = 00


+---------------------------------+
|  FILES                          |
+---------------------------------+

File BIOS_5170_10JAN84_U27_6181028_27256.BIN is a binary image of ROM chip U27.  [ 32 KB in size ]
File BIOS_5170_10JAN84_U47_6181029_27256.BIN is a binary image of ROM chip U47.  [ 32 KB in size ]


+---------------------------------+
|  USING FILES TO MAKE EPROMS     |
+---------------------------------+

1. Obtain two blank 27256, or 27C256, EPROM's rated at 250 ns (or less [faster]).

2. Burn file BIOS_5170_10JAN84_U27_6181028_27256.BIN to the first 27256, then label the 27256 as "U27".

3. Burn file BIOS_5170_10JAN84_U47_6181029_27256.BIN to the second 27256, then label the 27256 as "U47".


+---------------------------------+
|  IMPORTANT                      |
+---------------------------------+

To use this 2-ROM version of the 10JAN84 revision BIOS on a 5170 motherboard of type 1, shunt block U131 on the motherboard needs to be set to the '27256' position.
See http://minuszerodegrees.net/5170/misc/5170_motherboard_switch_settings.htm





