I need a Little help from my friends

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  • #947
    Kotec53
    Participant

    Hello,
    I solved my hardware problems and now a write in the eeprom is well done in the ram.
    the burning test is running without error, Game of life and Tiny Basic are working.
    I can save and load a small program in basic without any problem.

    CPM loads correctly but I have a problem:
    the first command works (example dir) but all the following commands fail with a question mark.
    Where is the bug ?
    I tried several versions of cpm, with always the same problem.
    I don’t know where to look, nor where to start to debug my card
    Thanks for your help.
    René

    link for screen_image
    https://drive.google.com/file/d/110m827PbrlkVToCT6Jf9TlKys9_odOUZ/view?usp=sharing
    Translated with http://www.DeepL.com/Translator (free version)

    #948
    Phil_G
    Moderator

    Hi René
    ‘dir’ is an internal ccp command so it looks to me like the ccp is getting corrupted. Game of Life, Tiny Basic and the break-in test all run in low memory, could it be that your memory chip has a problem in the upper half?
    Which memory chip is it?
    Beware that some Chinese 64k chips are actually failed 128k chips, on these the upper address line A16 of the 128k is still present and should be grounded, and any unused or no-connection pins should also be grounded. Since everything in low memory works ok but CP/M which uses high memory fails, I suspect ram problems 🙂
    Cheers
    Phil

    #959
    Kotec53
    Participant

    Hello,
    I will clarify the problem.
    1)I boot my card : I arrive on the monitor menu.
    2) I choose “c” to launch cpm
    3) if I type a command, it works only once, after the commands are refused with a “?
    4) I can launch “vi.com“, “sargon.com” or “stat.com” present on the disk A and everything works.
    5) the problem is that only one command works, after that it’s dead!
    for example, impossible to do “B:” then “dir” : B: works and goes on disk B, but dir is rejected ….
    I’m looking for the bug in ccp or in Z80ccp, but I don’t know where to look
    Help !

    My ram is a AS6C1008 and it look like OK

    Translated with http://www.DeepL.com/Translator (free version)

    #960
    Phil_G
    Moderator

    Theres no bug in either ccp René 🙂
    On the AS6C1008, have you got pins 1 (NC) and 2 (A16) grounded ?
    Pin 1 is NC but we have found that it still needs grounding or high memory problems can appear. All the .com programs run in low memory so this could be a high memory problem and could be the result of a floating pin next to an unused address pin. Its worth a try 🙂
    Cheers
    Phil

    #961
    Steve
    Participant

    HI Kotec53
    What happens if you enter control-C at the prompt? Control-C should perform a WARMBOOT, which reloads CCP.

    Another thing to look for, is your JUMP vectors, are they being overwritten perhaps, check in core.asm and core_jump.asm.

    Don’t forget, John’s CP/M is not using a REAL BIOS. The DIR command is implemented by John in memorystick.asm

    Good luck
    Steve

    #962
    skx
    Participant

    What happens if you enter control-C at the prompt? Control-C should perform a WARMBOOT, which reloads CCP.

    Remember of course that this is not yet implemented, as per:

    github.com/z80playground/cpm-fat/issues/65

    As for the problem, it seems to be the same as the one I reported here:

    8bitstack.co.uk/forums/topic/faulty-hardware

    The solution was to swap out the RAM chip. Thought a temporary workaround of shorting that pin to ground resolved the problem too.

    #963
    Kotec53
    Participant

    Hello,
    I find the “bug” !!!
    No , it’s not the ram chip !!!

    It’s just my teraterm on the PC, It send CR+LF on return key !!!!
    The positiv side of this “bug”, is that I go in the code of ccp and begin to understand the making of it .
    Thank for all your remarks .
    Now, I can play with my card and with my programs .
    Good day for me and you
    Bye

    • This reply was modified 6 months, 2 weeks ago by Kotec53. Reason: nada
    #967
    john
    Keymaster

    Ah good, you figured it out. I was about to say it was the line endings. If you have CR/LF configured it sends CR to end one command, then the next command starts with a LF, which is obviously rubbish, so doesn’t work.

    #969
    Kotec53
    Participant

    This is exactly what was happening.
    Sometimes you want to slap yourself in the face!
    I’ve been pissed off for three days about this bug that wasn’t a bug.
    Now I’m going to play with my nice cp/m on my hole card.
    I bought a nice wooden box, in a DIY shop, to put my precious “computerosaurus” in.
    I have to find an old VAG screen in the attic and put the ESP32-VGA module I received in place!
    A few more days of fun.
    It reminds me of the joy of coding in assembler in the 80’s when I was young (and beautiful).
    Bye

    C’est exactement ce qui se passait .
    Des fois, on a envie de se donner des gifles !
    Trois jours que je me fais chier pour ce bug qui n’en était pas un.
    Maintenant, je vais jouer avec mon cp/m tout beau sur ma carte à trous .
    J’ai acheté une belle boite en bois , dans un magasin de bricolage, pour y mettre mon précieux “ordinosaure”.
    Il faut que je retrouve dans le grenier un vieux écran VAG et que je mettre en place le module ESP32-VGA que j’ai reçu !
    Encore quelques jours d’amusement.
    Celame rapelle la joie de coder en assembleur dans les années 80 quand j’étais jeune (et beau).
    Bye
    Translated with http://www.DeepL.com/Translator (free version)

    #970
    john
    Keymaster

    Old VGA monitors and PS2 keyboards are easy to find on websites where local people give things away for recycling. Or at least, they are here in the UK.

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