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Thread: CBM 8032 - What does the startup chirp actually mean?

  1. #151
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    Well done that man !

    Have you tested all of the PET functions yet?

    Do you have a cassette to load space invaders for example!!!

    We have had people get this far - and then something else doesn't work...

    It might be worth sending your 'dud' MC6845Ps so someone from VCFED near you who has an 8032 with a socketed CRTC to see if they get the same results. If they do, then either you have got a couple of duff ones in exactly the same way - or else they really don't work. The latter would be well worth knowing for future repairs...

    Perhaps dave_m (both of you in California)?

    Dave

  2. #152
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    Yes, I will be happy to send them to Dave_m or anyone else.

    As far as testing is concerned, I had to take the keyboard apart because several keys were not responding, but they all work now.
    I don't have a cassette unit, but I do have these....
    IMG_2332.jpgIMG_2333.jpg I have not tested them yet... that's the next thing on my list

  3. #153
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    Good summary. To be safe I will not use a 6845 in a PET. I wonder if anyone out there has a Motorola 6845 in their PET computer?

  4. #154
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    It appears that my Twin Floppy drive is not working I will start a new thread.

  5. #155
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    Quote Originally Posted by MikeP View Post
    Yes, I will be happy to send them to Dave_m or anyone else.
    Mike,
    my CRTC is not on a socket. Someone else will have to volunteer to do the test.

    IMG_2332.jpgIMG_2333.jpg I have not tested them yet... that's the next thing on my list
    I had both of those units back in the day (1980). Now I have only a 2040 that has been upgraded to 4040 firmware. When you get the 2040 working, I will help with firmware upgrade to fix a few things like the Initialize issue. With the 2040, one must remember to always initialize the drive every time a floppy is switched (to update the Block Allocation Map) or there may be corruption if the BAM does not match the floppy during a write. The 4040 firmware does this automatically with a change of floppies.

    Probably you will use the printer for BASIC program listings or to play with graph programs, but I remember using that printer with a word processor called "Word Pro" that I produced many a report for work and post-grad classes. The dot matrix fonts were rather ugly but did the trick. I hope you can find the proper ribbons.

  6. #156
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    Quote Originally Posted by MikeP View Post
    It appears that my Twin Floppy drive is not working I will start a new thread.
    OK off we go!

    With a Commodore drive, always remember to to remove the floppies when power is applied or turned off or you can corrupt the floppy.

  7. #157
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    Set ourselves the goal of getting space invaders running!

    Dave

  8. #158

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    Quote Originally Posted by MikeP View Post
    Hi Dave,

    Here is a summary...
    It was initially a failed 6545 CRT controller, which you and Daver2 identified. I de-soldered that and put in a socket and a MC6845P (Motorola). That fixed the horizontal drive, but not the vertical drive. I had bought 2 of the MC6845Ps, so I tried both and they both gave the exact same results. We did a lot more investigation, including the NOP Generator to test the address bus and the walking ones EPROM to test the data bus, both seem fine. Then Jannie mentioned that MC6845 is not compatible with PET, but UM6845 is compatible. I bought an original 6545 and a UM6845 (both arrived yesterday). They both work perfectly. I think it is therefore safe to assume that the MC6845 is NOT compatible with the PET (or not compatible with this particular version).

    Mike P.
    Woot!! Another PET lives!!

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