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NOTE:

This web site is not some kind of 'official' documentation hub for the XT-IDE card. It is simply the result of someone who decided to add to the documentation that exists elsewhere.

XTIDE Universal BIOS  -  For U17 U37 sockets on IBM 5170 motherboard


This web page provides a procedure for putting the XTIDE Universal BIOS (XUB) into ROM's for the U17 and U37 sockets on an IBM 5170 motherboard.


STEP 1

Execute the version of XTIDECFG that matches your version of XUB, then:
1. Read in the XT version of the BIN file (ide_xt.bin), then
2. Make the required configuration changes (see note 1 below) to suit your XT-IDE/XT-CF card, then
3. Write to file.

You now have an 8 KB sized XUB file that is both suitable for your XT-IDE/XT-CF card, and has an 8-bit checksum of 00.


STEP 2

Per here, a requirement is that the BIOS expansion ROM for the 5170's U17+U37 sockets is 64 KB sized, and, the entire 64 KB has an 8-bit checksum of 00.
So we need to 'extend' the 8 KB sized XUB file to 64 KB.

You can either:
1. Concatinate the BIN file eight times; or
2. Append 56 KB of zeroes (or any byte really) to the end of the BIN file, then modify any one of those 56K bytes so that the 8-bit checksum of the resulting 64 KB file is 00.

Re concatination.  A simple method is described in note 2 below.


STEP 3

Split the 64 KB sized file into odd and even files:
- One 32 KB sized file of even (low).
- One 32 KB sized file of odd (high).

The Windows program at here can do that for you.


STEP 4

Obtain two 27C256 EPROM's (or two Winbond W27E257), of a speed rating that does not violate the requirement at here.

Use an EPROM programmer to:
- Put the even/low file of step 3 into one of the 27C256's, which creates the chip that will go into socket U17.
- Put the odd/high file of step 3 into one of the 27C256's, which creates the chip that will go into socket U37.


STEP 5

Fit the chips.


STEP 6

Recommended.  On the IBM 5170, run RAYXTIDE to confirm that the XUB was found at address E0000.  What RAYXTIDE will also do is, seeing (via the IBM motherboard BIOS) that it is running on an IBM 5170, and seeing that the XUB starts at E0000, verify that the 8-bit checksum of the U17+U37 address space is 00.

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Note 1	The device/controller type, and the base I/O address.
Note 2	Use the DOS program named ROMFILL.EXE For example, to concatinate FRED.BIN as many times as required to create a 64 KB sized file named TARGET.BIN, type in:  romfill /64 fred.bin target.bin ROMFILL.EXE is found in the DOS folder within the pcxtbios31.zip file at at here.