This is a cryptographically signed message in MIME format. --===============0082194027== Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg=sha1; boundary="------------ms060902080504080601000203" This is a cryptographically signed message in MIME format. --------------ms060902080504080601000203 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit William Chops Westfield wrote: > On Feb 18, 2007, at 7:12 AM, Jake Vickers wrote: > > >>> why a C chip? (OTP) >>> >>> >> I'm working on a specific idea. I saw some stuff on the 'net for >> controlling relays (or LEDs, whatever) from a serial port utilizing >> a PIC chip. the code was written for a 12C671... >> > > Not a bad reason. But as your first "homework assignment" for > "learning about microcontrollers", I assign the following: :-) > > 1) What features of the 12C671 are important to your project ? > 2) Which reprogrammable ("F" series) part comes closest to > matching the capabilities of the 12C671 > 2a) Which F-series part comes closest to meeting your > project requirements? Is it the same? > 2b) Which F-series part that meets the project requirements > is easiest for you to get at your location? > 3) What differences between the 12C671 and the part you've found > will require specific attention to port the old code? > > You might be able to make use of your OTP 12C671 (I assume it doesn't > have a clear window in the top, in which case it's UV-eraseable) by > overwriting your LED-blink code with 0s (NOP) and putting new code > in the as-yet-unprogrammed section of the EPROM. that'll depend on > exactly how your programming SW works, but it could work... > This is fun! ;) What features of the 12C671 are important to me? Small, cheap, I can control 3-4 outputs to turn on a LED/relay and have an input that gets it's data from a computer's serial port. That and the code that I found already is written for it. I'm sure there's LOTS of other chips that allow this as well. I didn't realize that it was a OTP chip, so it made for an expensive LED flasher as an experiment, but that's alright. Knowledge isn't free, eh? I found this page (http://melabs.picbasic.com/Scripts/perl/pic.pl) that gives me a decent comparison of what the chips do (the only one I found that was quick and easy to read), so it looks like there's a multitude of PICs that can do what I need. I won't list all the ones that fit my parameters, since the list is long, and still fails to tell me which ones are replaced by newer chips. Guess I'll just have to learn that with experience. But this list DOES tell me which ones are OTP, which is a great boon for me. But it looks like the 12F675 might be the closest that still allows me to flash it again easily. And it was cheaper than the 12C671 I bought. And yes, it's the same from what I can see besides having a 10-bit ADC resolution. And no, it didn't let me overwrite the old code. > > Well, books or school classes wouldn't necessarily be any less > out-of-date; that doesn't make them useless... Very little of what > you learn about a 16F84 is USELESS; it's just that it should be > applied on modern technology rather than actual 16F84 chips... > > True. Still doesn't hurt to learn to do things in DOS in my opinion either. If nothing else it familiarizes with the way things work below the surface. Thanks for the help and info! --------------ms060902080504080601000203 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIJKTCC Au8wggJYoAMCAQICEBnmFGEXUbd7XMyZELrHw6IwDQYJKoZIhvcNAQEFBQAwYjELMAkGA1UE BhMCWkExJTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMT I1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBMB4XDTA2MTIwMTE3MjgxNFoX DTA3MTIwMTE3MjgxNFowWTEQMA4GA1UEBBMHVmlja2VyczEOMAwGA1UEKhMFSmFjb2IxFjAU BgNVBAMTDUphY29iIFZpY2tlcnMxHTAbBgkqhkiG9w0BCQEWDmpha2VAdjJnbnUuY29tMIIB IjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyCy4+uWH+iVSjFMv+LNNnIaRc7wp0mwe 33IB4i0esCy1EHSLSy5tGYVV/9sEbkUcfnvTqAHs2uzPMbhp03WLaOLakMbasGKusNa4xbOQ 9YDQEE+QfGkcLXQ063VEJiYDFslVfVI9l6y0axQE091ajt23SrUuMDq6r0GVXcpa8nTyYHO1 +9Fd8z2DqF2omIDdfTkV8kkgQ25ApXu53b6NobDTyY4ajKkLV0bn1S/CD88wQe4PmiXEALOQ j5ylzoVylpsFdLwr8D8qCdTp5KnYY1O1cJouVHUq/A3pIsdcDmhJHcV1DAjIBWocoQzLDtDl 66Eiv4N4+c7GCqRmBbfktwIDAQABoyswKTAZBgNVHREEEjAQgQ5qYWtlQHYyZ251LmNvbTAM BgNVHRMBAf8EAjAAMA0GCSqGSIb3DQEBBQUAA4GBABUF/vVvv1ou7/aO/S8dExqocdKcXyTO IiLJFGKK74EGzpT/zXiI2YQYNF4UYkQb77rYe6emuXwVvXf7cT9dXGUMHy8aM/3wEvGG4eER cxKBI4yQ6TZYDQhIw6W6Sn9u13m/P+v/KgaOepxrIUYup5A7PtlYVYrva/2Whni13j80MIIC 7zCCAligAwIBAgIQGeYUYRdRt3tczJkQusfDojANBgkqhkiG9w0BAQUFADBiMQswCQYDVQQG EwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMj VGhhd3RlIFBlcnNvbmFsIEZyZWVtYWlsIElzc3VpbmcgQ0EwHhcNMDYxMjAxMTcyODE0WhcN MDcxMjAxMTcyODE0WjBZMRAwDgYDVQQEEwdWaWNrZXJzMQ4wDAYDVQQqEwVKYWNvYjEWMBQG A1UEAxMNSmFjb2IgVmlja2VyczEdMBsGCSqGSIb3DQEJARYOamFrZUB2MmdudS5jb20wggEi MA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDILLj65Yf6JVKMUy/4s02chpFzvCnSbB7f cgHiLR6wLLUQdItLLm0ZhVX/2wRuRRx+e9OoAeza7M8xuGnTdYto4tqQxtqwYq6w1rjFs5D1 gNAQT5B8aRwtdDTrdUQmJgMWyVV9Uj2XrLRrFATT3VqO3bdKtS4wOrqvQZVdylrydPJgc7X7 0V3zPYOoXaiYgN19ORXySSBDbkCle7ndvo2hsNPJjhqMqQtXRufVL8IPzzBB7g+aJcQAs5CP nKXOhXKWmwV0vCvwPyoJ1OnkqdhjU7Vwmi5UdSr8Dekix1wOaEkdxXUMCMgFahyhDMsO0OXr oSK/g3j5zsYKpGYFt+S3AgMBAAGjKzApMBkGA1UdEQQSMBCBDmpha2VAdjJnbnUuY29tMAwG A1UdEwEB/wQCMAAwDQYJKoZIhvcNAQEFBQADgYEAFQX+9W+/Wi7v9o79Lx0TGqhx0pxfJM4i IskUYorvgQbOlP/NeIjZhBg0XhRiRBvvuth7p6a5fBW9d/txP11cZQwfLxoz/fAS8Ybh4RFz EoEjjJDpNlgNCEjDpbpKf27Xeb8/6/8qBo56nGshRi6nkDs+2VhViu9r/ZaGeLXePzQwggM/ MIICqKADAgECAgENMA0GCSqGSIb3DQEBBQUAMIHRMQswCQYDVQQGEwJaQTEVMBMGA1UECBMM V2VzdGVybiBDYXBlMRIwEAYDVQQHEwlDYXBlIFRvd24xGjAYBgNVBAoTEVRoYXd0ZSBDb25z dWx0aW5nMSgwJgYDVQQLEx9DZXJ0aWZpY2F0aW9uIFNlcnZpY2VzIERpdmlzaW9uMSQwIgYD VQQDExtUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgQ0ExKzApBgkqhkiG9w0BCQEWHHBlcnNv bmFsLWZyZWVtYWlsQHRoYXd0ZS5jb20wHhcNMDMwNzE3MDAwMDAwWhcNMTMwNzE2MjM1OTU5 WjBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRk LjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVtYWlsIElzc3VpbmcgQ0EwgZ8wDQYJ KoZIhvcNAQEBBQADgY0AMIGJAoGBAMSmPFVzVftOucqZWh5owHUEcJ3f6f+jHuy9zfVb8hp2 vX8MOmHyv1HOAdTlUAow1wJjWiyJFXCO3cnwK4Vaqj9xVsuvPAsH5/EfkTYkKhPPK9Xzgnc9 A74r/rsYPge/QIACZNenprufZdHFKlSFD0gEf6e20TxhBEAeZBlyYLf7AgMBAAGjgZQwgZEw EgYDVR0TAQH/BAgwBgEB/wIBADBDBgNVHR8EPDA6MDigNqA0hjJodHRwOi8vY3JsLnRoYXd0 ZS5jb20vVGhhd3RlUGVyc29uYWxGcmVlbWFpbENBLmNybDALBgNVHQ8EBAMCAQYwKQYDVR0R BCIwIKQeMBwxGjAYBgNVBAMTEVByaXZhdGVMYWJlbDItMTM4MA0GCSqGSIb3DQEBBQUAA4GB AEiM0VCD6gsuzA2jZqxnD3+vrL7CF6FDlpSdf0whuPg2H6otnzYvwPQcUCCTcDz9reFhYsPZ Ohl+hLGZGwDFGguCdJ4lUJRix9sncVcljd2pnDmOjCBPZV+V2vf3h9bGCE6u9uo05RAaWzVN d+NWIXiC3CEZNd4ksdMdRv9dX2VPMYIDZDCCA2ACAQEwdjBiMQswCQYDVQQGEwJaQTElMCMG A1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBl cnNvbmFsIEZyZWVtYWlsIElzc3VpbmcgQ0ECEBnmFGEXUbd7XMyZELrHw6IwCQYFKw4DAhoF AKCCAcMwGAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMDcwMjE5 MTMzMDQ2WjAjBgkqhkiG9w0BCQQxFgQUhjX6El/FfnZqBq9ZPcdTA94vfRYwUgYJKoZIhvcN AQkPMUUwQzAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwICAUAwBwYF Kw4DAgcwDQYIKoZIhvcNAwICASgwgYUGCSsGAQQBgjcQBDF4MHYwYjELMAkGA1UEBhMCWkEx JTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMTI1RoYXd0 ZSBQZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBAhAZ5hRhF1G3e1zMmRC6x8OiMIGHBgsq hkiG9w0BCRACCzF4oHYwYjELMAkGA1UEBhMCWkExJTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0 aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMTI1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBJc3N1 aW5nIENBAhAZ5hRhF1G3e1zMmRC6x8OiMA0GCSqGSIb3DQEBAQUABIIBAABKB/Cvi1saRl19 s1NDvORYGC78ohBAx56BmbCV7HfAeLrnKmw8F4oSiKk+6CVHIyQABeVEqeMS8TLh4QJgwIph n6V3hJXfFdoyvRgWQ+wHPmGDOjl8g3uKwcpM/L618f0bz/Pz/G+1Eoy3nUiZt39zuqUkDZ+K IOn6hHWaNInCCAerBbMcunCKEIIwm0enWJHKLPSm2iIYzuBJ0gbdtC+J6KKAYhlbAIA1oX/c wSrrXHPWN8m2E6BNvkgFDsNrEqGAnb9IHfRUqCKus9LDZONTEsd75qUR9HayuGkh6/mEK92c twTFE1yIQNjFpSmLcJpSmJNtdMtx1oNEWJG85FMAAAAAAAA= --------------ms060902080504080601000203-- --===============0082194027== Content-Type: text/plain; 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