Last revision of this page: February 2, 2025

A few days ago it happened again, I had to burn an EPROM, but I didn't have a suitable EPROM in my spare parts box. What to do? In my case I needed a 2716 EPROM with 2 KByte. But available were only a whole dozen 2732 EPROMs with 4 KByte. If the EPROMs are pin compatible, as in this case, then you can ...

Option 1

... copy the 2 KB ROM into the upper half of the 4 KB EPROM.

Option 2

... simply double the image to 4 KB and then burn it to a 4 KB EPROM as usual. You ca do the doubling simply under DOS with:

C:> COPY SOURCE.BIN /B + SOURCE.BIN /B TARGET.BIN /B

or

C:> COPY 2KB.ROM /B + 2KB.ROM /B 4KB.ROM /B

As an aside: You can quadruple a BIOS image in the same way! As already said, you only have to make sure that the EPROMS are pin compatible and of course the number of PINs must be the same.

Have a look at the - fantastic - pin assignment overview by Wolfgang Wrobel.

• Wolfgang Wrobel (2014): Pin assignment overview.