This board replaces the 6 original ROMs (D0,D8,E0,E8,F0,F8) on the motherboard.
The board is compatible with Apple II, Apple II+, Apple II
Europlus. (Note it is not compatible with J-Plus)
You get two replacement ROM images, one with exactly the same content as your original 6 ROM’s containing AppleSoft Basic, and another ROM image with the DEADTEST diagnostic program. Deadtest is an extensive DRAM test, more info can be found if you google "Misterblack Apple II deadtest on github"
The 32Kx8 EPROM on this board contains 2 ROM images or banks, selectable with a jumper.
The first bank (Jumper ON) contains the exact same contents as the original Apple ROM’s, five Applesoft BASIC ROMs D000, D800, E000, E800, F000 and the auto start boot ROM F800.
The second bank (Jumper OFF) contains the Deadtest DRAM test. When you boot up the computer, it start executing this test automatically, and will identify any bad DRAM chips. It gives audio feedback with beeps and also a summary screen that identifies any bad DRAM IC’s.
See the memory map of the Eprom in one of the attached photographs.
There
is free software to create your ROM images available. See the photo’s for the download site for the
HxD software. Then follow the two additional photos on how to build your
ROM. It is a simple drag and drop of 2K
bytes .bin files. The second to last photo chows this actual ROM build. This
board is compatible with, a classic
27C256 32Kx8 EPROM or a 27E257 or 27C257
EEPROM, so if you don't have a UV eraser, no worries, just use a Flash EEPROM. (see the Photo of these devices)
Installation of the ROM card:
First remove all the six ROM’s from the mother board and also the IC at location F12.
The board plugs into the D0 socket and also into the socket at location F12 (you have to remove the IC there (74LS138).
There are many detailed documentations on the web available to assist you. See some links on one of the photos.
Take your time to make sure all the pins are aligned before putting pressure on the board to seat it. Use a flashlight, small mirror or a good pair of magnification glasses to look at the socket.
WARNING: The board will obstruct installation of expansion cards longer than Apple Disk II controller into slot 6 and 7.
One more thing: (where did I hear that before?)
This board has small gold plated pins of only 0.5mm diameter to plug into your Apple II mother board.
These are the thinnest pins available and will not damage your precious mother board sockets. (see photo)
Some other ROM boards have round 0.6mm pins or square pins of 0.65mm (normal header pins, like the one on this board for the Jumper).
The EPROM socket is also gold plated, round machined pins that are of high quality compared to standard IC sockets. Should you want to remove this EPROM to modify its contents then you have nothing to worry about.
Please be aware that the software contained on
the Apple II ROMs is still under license by Apple! If you own an original Apple
II then you are implicitly licensed to use the software in the ROM of that
machine.
Under no circumstance should you use any Apple II ROM image if you are not
legally entitled to do so.