- Joined: 17 Feb 2021
- Posts: 7
- Location: Wellington, NZ
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Basic IIIB Rom replacement
 Posted: Wed Feb 17, 2021 6:51 pm
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Hi,
I have a Basic Level IIIB cartridge which is giving the 2 beep Rom error message.
Can the Rom chip be directly replaced with a 27C256 chip?
Thanks
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- Joined: 17 Feb 2021
- Posts: 7
- Location: Wellington, NZ
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Posted: Thu Feb 18, 2021 10:27 pm
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So I went ahead and tried it but get the same result.
2 Beeps and a black screen. Could this be a fault with the 74LS157's or 74LS32?
Or could it be a RAM fault?
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- Joined: 17 Feb 2021
- Posts: 7
- Location: Wellington, NZ
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Posted: Fri Feb 19, 2021 12:38 am
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OK I managed to find replacements for the 3 74LS chips and have the same result.
I'm thinking the issue must now unfortunately reside with the RAM chips.
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- Joined: 17 Feb 2021
- Posts: 7
- Location: Wellington, NZ
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Posted: Fri Feb 19, 2021 3:55 am
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Progress when it’s giving me the 2 beeps if I press reset I get the green basic screen but with 0 bytes free.
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