Phoenix and Pleiads test ROM

philmurr

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I was chatting to a fellow collector last week about a faulty Phoenix board he has, and we got talking about a test ROM for the board.

I had a bit of time this weekend so adapted the Moon Cresta/Scramble/Super Cobra test ROMs that I put together a while ago, and the result is a test ROM for Phoenix. As it happens exactly the same test ROM works for Pleiads as they run on pretty much the same hardware. It's been tested on an original Amstar and a bootleg Phoenix board (although all Phoenix boards I've ever seen are identical), and a Centuri Pleiads, so should work on all variants.

The one drawback is that it relies on being able to display the results of the tests on screen, so if your board is completely dead it won't really help you...

The test ROM tests both banks of the 2 x 1K areas of RAM (4000-43FF & 4800-4BFF), and also displays the status of inputs and DIP switches. An explanation of the tests follows, and photos of the tests are attached, some from Mame and some from a real Phoenix board

Pic 1 - First powered up, and during testing - it writes a number of values to each RAM location and reads back to ensure the correct value has been stored. The screen will show a constant changing pattern.

Pic 2 - RAM test failure and it displays the bank and RAM area at the top of the screen. If it fails then it stops all further tests, so this may not be the only fault. The failure below indicates RAM area 4000-43FF, bank 0 (RAM 0 Bank 0). This is (on Phoenix) IC41/IC43. The other failures (again on Phoenix board) indicate:-

Bank 0 RAM 1 - IC42/IC44
Bank 1 RAM 0 - IC25/IC27
Bank 1 RAM 1 - IC26/IC28

On Pleiads:

Bank 0 RAM 0 - IC40/IC42
Bank 0 RAM 1 - IC41/IC43
Bank 1 RAM 0 - IC22/IC24
Bank 1 RAM 1 - IC23/IC25

Pic 3 - Passed RAM tests, and here it tests DIPs and inputs

DIP switches 0-6 can be read and displayed. DIP switch 7 (cocktail mode) can't be read by the game, instead bit 7 displayed on the picture is the VBlank signal (so meaningless really as far as tests are concerned). In these tests, 0=on

The player inputs are BLRF-21C, which are Barrier, Left, Right, Fire, Not used, P2 start, P1 start, Coin - 0=pressed/selected

You need to burn the test code to a 2716 EPROM, and replace IC45 (Phoenix) or IC47 (Pleiads). 4th pic shows it installed on a Centuri Pleiads board.

Test ROM code is attached.
 

Attachments

  • Phoenix testing.JPG
    Phoenix testing.JPG
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  • Phoenix ram fail.JPG
    Phoenix ram fail.JPG
    125.4 KB · Views: 40
  • Inputs and DIPs.JPG
    Inputs and DIPs.JPG
    34.9 KB · Views: 43
  • Pleiads board.JPG
    Pleiads board.JPG
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  • phpltestrom.zip
    532 bytes · Views: 26
Working on a Centuri Phoenix with an issue where on a two-player game, the game immediately freezes up when switching to player 2. I tried Phil's test ROM and it went through the testing, with screens similar to what Phil shows, but in the top information row, I just get garbage on screen.

I conversed with Phil on this issue and he explained that player-1 and player-2 use different banks of RAM. He suggested replacing the player-2 RAM in this order: IC42, IC44, IC26, IC28. I replaced IC42 (I desoldered it and the 2114 did test bad), replaced it, and BANG! Game working 100%. The test ROM now also shows proper results.

Thanks Phil for another great test ROM, and especially for your help in debugging. How did you figure out which RAM player-1 and player-2 use?
 
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How did you figure out which RAM player-1 and player-2 use?

IC41,42,43 & 44 are foreground RAM. IC41 & 43 are P1, IC42 & 44 are P2

IC25, 26, 27 & 28 are background RAM. IC 25 & 27 are P1, IC26 & 28 are P2

Your photo of the failed test showed garbage at the top of the screen where it should have said "BANKx RAMx" so I suspected foreground RAM. As P1 worked perfectly that led me to suggest P2 foreground which is IC42 & 44. You got lucky with the first one being the faulty one :)
 
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