Nice work, I have some weird problems on a System 6 board. I'll get some more 2716 ROMS and do some testing. My board is modified to run the Firepower Combo ROM. will these tests still work?

@barakandl Thanks for the board info above. I built a board based on your drawings, just on a perf board not a PCB. It all tests OK with a continuity etc. I burnt the combined image onto a 27C256 and installed the chip. I then tested the board in my Rom burner, reading every option for the 4 dips back into the Rom burner. All work exactly as expected, except for when all 4 select dips are set to ON, this should select image 0 - Bus, but it selects image 4 - RAM1. It seems like dip3 is not turning ON, but it is, otherwise I couldn't select 11 lamps, 10 timer etc. Any idea what is going wrong?

I checked all 4 lines that are connected to the dips, I get 4.98v when the dip is open and 0v when the dip is closed. I also checked the image in the 27C256 and it looks to me that ROM 0 is the first one in the list. I did this in case ROM 4 was accidentally written to the 27C256.

Is there any chance that when all 4 addresses are low it does not select the first chunk, as in should it be some other combination of address pins?

Unfortunately I can't report back on very much yet. I have 2 System 6 boards that will not pass the LED test, so I am stuck at the BUS (ROM 0) test. given my issue above with selecting ROM 0, I burnt a 2716 with ROM 0 for testing.

While I'm here, I should check some things:
I understand that these test ROMs are designed to be used with the boards in the game. Can I use the ROMS with the boards on the test bench instead?
Do the ROMs, including the BUS ROM, only work correctly if the driver board is connected?

On 1 of my boards Pin34 on the CPU is high but J1 is installed and R4 is removed and a 6808 is installed - so I need to figure out what is going wrong there.

On both System 6 boards I have some address lines that are not as per your expected conditions. I'll look to trace those lines through the board to see where the problem lies.

pincoder Thanks, I'll burn a new ROM in a couple of days and I'll let you know how it goes.

In the end there is nothing wrong with the 27C256 image or the schematics for the adapter board, i was just misreading the information from my ROM burner. So have confidence with burning a 27C256 chip and making an adapter board.

I haven't tested any of the ROMS other than 00. I'm stuck at the 00 Bus ROM ROM. neither of my boards will run the 01 LED ROM.

With 00 ROM I have all the correct signals at IC1 (CPU) except for pin 9 A0, which is low, and should be high. I can't find a short of any kind and there is continuity from pin 9 to the buffer chip and from the buffer chip to the IC17 ROM.

I am testing on a workbench and if I detach the driver board all the datalines are low, I don't know if this is normal or if it is a clue.

Tonight, I will test with Leon's test chip, I have already tested with Marco's and I get 1 long flash then a locked LED, if I am interpreting correctly it means that the first ROM is not testing correctly, but replacing the ROM makes no difference.

I didn't have a chance to do more testing, the board just started to work again, there must be an intermittent connection or short on the board. Hard to find now, so I'll just wait until it fails again.

I have another board with a similar problem, but I am fairly sure the issue is caused by previous battery damage that was not cleaned up fully.

With my System 6 board now working, I tested all of the ROMs. Well most, I didn't try 06 RAM3 test because that is for System 7, I also did not try 14, 15 or 16 for clearing Init and Edit of CMOS.

Everything worked as expected, the Switch test in particular is very handy when testing the trough switches as it shows up to 12 switch closures at the same time.

Thanks for writing these ROMs.

The title of this thread suggests the ROMs are for System 3, 4 and 6, but in the documents there is reference to System 7.
Can I use these ROMs for System 7? Which IC socket on the System 7 board should I insert the ROM into?