XT clones commonly have sockets for ROM BASIC just like the original machines.

On the IBM 5150 you'll have 4 ROM BASIC sockets which i suppose to be 8kb each. The first socket starts at F600h, the second at F800h and the last to at FA00 and FC00 respectively. On the IBM XT 5160 this arrangement was slightly changed. Socket U19 contains ROM BIOS and the first 8kb of ROM BASIC and socket U18 cotains the last 24kb.

On XT clones though you could either find a similar IBM 5150 arrangement or by just a single 32kb ROM socket. One would guess that you can just simply concatenate the 4 ROM BASIC files in proper order in a single file, burn a 27256 compatible EPROM/EEPROM and you're good to go. I tried it and failed:

As you can see ROM BASIC is detected by the system BIOS but it hangs after it tries to boot from ROM BASIC. A little character artifact is shown on the second picture.

I wanted to get this working so i decided to try all 16 possible combinations for rearranging the ROM BASIC. I tried twice and failed again. So instead of trying 13 more times i searched around the web and curiously enough there was someone on VCF was able to solved this problem:

http://www.vintage-computer.com/vcforum/showt … 6431#post266431

The correct order for cocatenating a 32kb ROM BASIC is

BASICC11.F8+BASICC11.FA+BASICC11.FC+BASICC11.F6

So it could be that the address lines for the socket on some of these XT clone motherboards were done in a way that requires the order of the 4 8kb files to be changed. I don't see a reason for this but anyway, i tried and it does indeed work:

So there you go, if you want to add ROM BASIC to your XT clone board keep this in mind.