| Re: Has anyone reverse engineered SP0256A external serial speech ROM [message #10762 is a reply to message #10761] |
Tue, 14 May 2024 03:17   |
lynchaj
Messages: 1080
Registered: June 2016
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Senior Member |
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Hi Bill
One thing you can try is using the monitor and feeding allophone addresses directly to the SP0256. Also, put in an LED on the BUSY pin on the SP0256 which would light up during speech.
If you're not seeing any activity at all even on allophone 0, 1, 2, etc. or BUSY LED then you probably have a non-SP0256 fake like a relabeled OTP ROM. You could try identifying the chip in your programmer and see if that gives some clues. Try to read the contents like a 2764 EPROM. But they are mostly electronic junk
Only some of the fake SP0256s are relabeled SP0256A-xxx chips. They do that to give something that sort of works but not like you expect it would. Other fakes are like what you probably have which are just relabeled junk ICs like OTP ROMs or MCU with mask ROMs.
Here is an article on fake SP0256 chips. I think you'll recognize these parts
https://www.smbaker.com/counterfeitfakejustplainbad-sp0256a- al2-chips
Oh, how I detest the scammers!
[Updated on: Tue, 14 May 2024 03:20] Report message to a moderator |
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