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 IBM 5150 BIOS - USE OF A 27256 EPROM VIA 27xxx ADAPTER                                        
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The 27256 (or 27C256) EPROM is 32 KB sized.

So, for the 27256 (in a suitable adapter for the IBM 5150), what we will do is quadruple up the IBM 5150's 8 KB sized BIOS image, to get a 32 KB sized image.

+-----------------+
| 8 KB SIZED BIOS |
+-----------------+
| 8 KB SIZED BIOS |
+-----------------+
| 8 KB SIZED BIOS |
+-----------------+
| 8 KB SIZED BIOS |
+-----------------+

In Windows, we can do the quadrupling up via a command window.

The following assumes that the file containing the 8 KB sized BIOS image is named SOURCE.BIN

STEP 1: Open up a command window.

STEP 2. Change to the drive/folder that contains SOURCE.BIN

STEP 3. Enter in the following command:

        COPY SOURCE.BIN /B + SOURCE.BIN /B + SOURCE.BIN /B + SOURCE.BIN /B TARGET.BIN /B


The file TARGET.BIN has been created. Use that 32 KB sized file to populate your 27256 (or 27C256).


>>> For the 27OCT82 dated 5150 BIOS, I have already done this quadrupling for you.
    The resulting target file is http://minuszerodegrees.net/bios/BIOS_5150_27OCT82_U33_27C256.BIN