Apple iic ROM 255 UPGRADE

This is not an hack but an official Apple ii mod to upgrade a rom 255 apple iic to a more recent rom, it can be a rom 0 or rom 3 or rom4, i opted for the newer rom 4. rom 0 is ok to run smartport disks and also 3 and 4, rom 3 and 4 has access to the memory expansion that there is not in every motherboard, rom 4 has fixed some rom 3 errors. I made this mod to run floppy emu hard disks and floppy(still to try by me waiting femu).

The mod consists in cutting the connection between the 2 solders W1 in the apple iic motherboard with rom 255 and connect soldering the W2 joint. I used a cutter to remove the solder between w1 and a lens, it is very small. remove the rom chip gently with a flat screwdriver by pull up it on on side.and put on the new rom benting a little the pins all in a row with a flat surface. To check the rom  version write PRINT PEEK(64447) the result vary from 255 to 0/3/4.

Here apple instruction click here to see apple iic rom 255 motherboard mods

Here more clear photos click here to see more clear photos mods

Here a good rom upgrade kit on ebay click here to rom upgrade kit