

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 4-ROM version of the 10JAN84 revision BIOS, where each ROM is of type 27128 (or 27C128).
It will only work on type 1 motherboards, because only type 1 motherboards have the U131 shunt,  a shunt that allows use of 27128 type ROMs.

Note that most people will not use this 4-ROM version of the 10JAN84 revision BIOS, instead, they will use the later 2-ROM version (two ROMs of type 27256 [or 27C256]).


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

ROM chip U17 has the IBM part number of 6181024, and is 16K in size
ROM chip U27 has the IBM part number of 6181025, and is 16K in size
ROM chip U37 has the IBM part number of 6181026, and is 16K in size
ROM chip U47 has the IBM part number of 6181027, and is 16K in size


8-bit checksum of 6181024 = 35
8-bit checksum of 6181025 = 01
8-bit checksum of 6181026 = 81
8-bit checksum of 6181027 = 49
                           ----
                    added = 00


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

File IBM_5170_10JAN84_U17_6181024_27128.BIN is a binary image of ROM chip U17.  [ 16 KB in size ]
File IBM_5170_10JAN84_U27_6181025_27128.BIN is a binary image of ROM chip U27.  [ 16 KB in size ]
File IBM_5170_10JAN84_U37_6181026_27128.BIN is a binary image of ROM chip U37.  [ 16 KB in size ]
File IBM_5170_10JAN84_U47_6181027_27128.BIN is a binary image of ROM chip U47.  [ 16 KB in size ]


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

1. Obtain four blank 27128, or 27C128, ones rated at a maximum access time of 260 ns. (Or less, e.g. 250 ns.)

2. Burn file IBM_5170_10JAN84_U17_6181024_27128.BIN to the first 27128/27C128, then label the 27128/27C128 as "U17".

3. Burn file IBM_5170_10JAN84_U27_6181025_27128.BIN to the second 27128/27C128, then label the 27128/27C128 as "U27".

4. Burn file IBM_5170_10JAN84_U37_6181026_27128.BIN to the third 27128/27C128, then label the 27128/27C128 as "U37".

5. Burn file IBM_5170_10JAN84_U47_6181027_27128.BIN to the fourth 27128/27C128, then label the 27128/27C128 as "U47".


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

To use this 4-ROM version of the 10JAN84 revision BIOS, Shunt block U131 on the (type 1) motherboard needs to be set to the '27128' position.
See http://minuszerodegrees.net/5170/misc/5170_motherboard_switch_settings.htm





