New! Dark mode!

Browsing Pinside at night? Getting tired of all the white? Switch to dark mode using the button in the top right (or CTRL-B)!

(Topic ID: 230519)

System 7 test rom RAM tests

By zacaj

2 years ago

Topic Stats

  • 10 posts
  • 4 Pinsiders participating
  • Latest reply 1 year ago by OHMI_Arcade
  • Topic is favorited by 3 Pinsiders


Linked Games

No games have been linked to this topic.

    You're currently viewing posts by Pinsider zacaj.
    Click here to go back to viewing the entire thread.

    #1 2 years ago

    Trying to get a system 7 mpu booting, and I'm getting various 'bad RAM' readings.

    Leon's test rom locks the leds on immediately, but does not display 1,2, or 3 (which according to it should). Two leds no flashes indicates the IC13 RAM is bad.

    Andre's test rom blinks on 2 and 3, signifying that IC16 and IC19 are bad. Doesn't blink on 1 (IC13).

    Usually I find these tests pretty good on system 3-6 games, but I've never had a system 7 ram issue before. My confusion lies in the fact that IC13 and IC16 are different on system 3-6 vs system 7. on 3-6 they're the lower halves of the first 255 bytes of ram. on system 7 they each span the whole 255 bytes but each are only four bits. Both these test roms claim to work for system 3-7, so how can you tell which RAM on a system 7 is actually bad? It seems like if it just scans the full bytes (like it would for system 3-6) then it wouldn't know which chip it was that caused the error? A look at the source code for Andre's seems to read like it only scans full bytes, and thus won't produce accurate results on a system 7, but I may be misunderstanding...

    Can anyone confirm how to read these?
    Would marco's rom work better? I've never used it
    Is the system 7 self test more reliable than the system 3-6?

    #3 2 years ago
    Quoted from barakandl:

    Because of this i'd expect odd results from RAM tests for system 7. Either 2114 being bad should result in Andre's or Leon's test to repair fail at BOTH spots if I am thinking about it right.

    Thats what I would expect for a system 3-6 test being used in a system 6, but both my roms specifically say they support system 7? And Andres is saying one 2114 is good and one is bad?

    #5 2 years ago
    Quoted from barakandl:

    Instead of an entire bad chip it could just be detecting one or a couple bad bits somewhere and it plots out the location based on sys 3-6 layout which may not match system 7.
    Andre's ROM has no way to detect system 3-6 vs sys 7. I am going to assume the RAM tests are based on the layout of system 3-6 games which isnt going to line up properly to system 7.
    I'd honestly pull the most suspect chip out and test it in a RAM tester than do the other other if the first one pulled wasnt the bad RAM.

    None of the rams on any of my system 7s are socketed, so I can't test. Going to just have to remove and socket one by one, and have new rams on standby

    Or maybe I'll just write a system 7 ram test rom...

    #7 2 years ago
    Quoted from barakandl:

    Try the real sys 7 flipper roms. As long as it boots up somewhat I'd trust that ram test more than leon or Andre

    So those are more reliable? I've heard that the sys3-6 ones can't really be trusted. I tried them and got a 2, which again points to one of the RAMs

    Promoted items from the Pinside Marketplace
    $ 115.00
    Playfield - Toys/Add-ons
    ModFather Pinball Mods
    $ 50.00
    Playfield - Toys/Add-ons
    Back Alley Creations
    £ 29.00
    Lighting - Led
    $ 199.99
    Lighting - Other
    Lighted Pinball Mods
    $ 29.95
    From: $ 42.00
    Cabinet - Shooter Rods
    ModFather Pinball Mods
    € 60.00
    Playfield - Toys/Add-ons
    Creo Pinball
    $ 299.99
    Cabinet - Toppers
    Top-Notch Target Shields
    $ 14.95
    Playfield - Toys/Add-ons
    $ 369.00
    Cabinet - Decals
    From: $ 15.00
    From: $ 42.00
    Cabinet - Shooter Rods
    ModFather Pinball Mods
    $ 26.50
    Playfield - Toys/Add-ons
    The MOD Couple
    $ 7,599.00
    Pinball Machine
    Gulf Coast Pinball, LLC
    $ 45.99
    Matt's Basement Arcade
    $ 7.00
    Playfield - Decals
    Pinball Haus
    $ 9.99
    Cabinet - Other
    Bent Mods
    $ 64.00
    $ 29.95
    Gameroom - Decorations
    Pinball Photos LLC
    $ 25.00
    Cabinet - Other
    Filament Printing
    $ 10.00
    Playfield - Other
    Loop Combo Pinball
    From: $ 15.00
    Apparel - Men
    Pinside Shop
    € 9.10
    Flipper Parts
    $ 79.99
    Cabinet - Armor And Blades
    PinGraffix Pinside Shop
    $ 99.99
    Playfield - Toys/Add-ons
    Lighted Pinball Mods
    $ 99.99
    Playfield - Toys/Add-ons
    Lighted Pinball Mods
    $ 88.00
    $ 54.00
    Playfield - Toys/Add-ons
    € 40.00
    Playfield - Toys/Add-ons
    $ 45.00

    You're currently viewing posts by Pinsider zacaj.
    Click here to go back to viewing the entire thread.

    Hey there! Got a moment?

    Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside