Need CBIOS loader program - CP/M

This is a discussion on Need CBIOS loader program - CP/M ; I'm in the process of making major changes to my CPM 2.2 BIOS program. My current BIOS/Monitor is stored in 6k of EPROM at E000-EFFF. The lower 4k is banked as two 2k sections. One for monitor routines, one for ...

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Thread: Need CBIOS loader program

  1. Need CBIOS loader program

    I'm in the process of making major changes to my CPM 2.2 BIOS program.
    My current BIOS/Monitor is stored in 6k of EPROM at E000-EFFF. The
    lower
    4k is banked as two 2k sections. One for monitor routines, one for disk
    operations.
    My CCP/BDOS occupy addresses C800-DFFF.

    As with any major revision, errors (bugs) are numerous. After burning 3
    sets of
    EPROMS, I decided to try using a test BIOS in RAM at a lower address.
    For
    example. I will ORG the BIOS at A800 and disable the bank feature. Once
    I
    get it debuged, I will return to my EPROM procedure.

    What I need is a program to load my file and move it to location A800,
    then
    jump to the start at A800. Not too difficult to write, but I first
    thought that
    someone must have already written such a program. My old BIOS/CPM
    will load this program and then the test version will take over.

    I would just like to enter:

    LOAD TESTBIOS A800

    and it would load my Test BIOS at A800, then jump to A800.
    Anyone have such a program ????
    (If the source is provided, I perfer Zilog/Mostek type of code)
    Thanks.....
    Old-Timer John JDGILL at JUNO dot COM


  2. Re: Need CBIOS loader program

    On 28 Feb 2006 12:12:12 -0800, "Old-Timer" wrote:

    >I'm in the process of making major changes to my CPM 2.2 BIOS program.
    >My current BIOS/Monitor is stored in 6k of EPROM at E000-EFFF. The
    >lower
    >4k is banked as two 2k sections. One for monitor routines, one for disk
    >operations.
    >My CCP/BDOS occupy addresses C800-DFFF.
    >
    >As with any major revision, errors (bugs) are numerous. After burning 3
    >sets of
    >EPROMS, I decided to try using a test BIOS in RAM at a lower address.
    >For
    >example. I will ORG the BIOS at A800 and disable the bank feature. Once
    >I
    >get it debuged, I will return to my EPROM procedure.
    >
    >What I need is a program to load my file and move it to location A800,
    >then
    >jump to the start at A800. Not too difficult to write, but I first
    >thought that
    >someone must have already written such a program. My old BIOS/CPM
    >will load this program and then the test version will take over.
    >
    >I would just like to enter:
    >
    > LOAD TESTBIOS A800
    >
    >and it would load my Test BIOS at A800, then jump to A800.
    >Anyone have such a program ????
    >(If the source is provided, I perfer Zilog/Mostek type of code)
    >Thanks.....
    >Old-Timer John JDGILL at JUNO dot COM


    Try this:

    DDT testbios.hex

    at the command prompt type

    R bias ("bias" is whatever is needed to assure the load address per
    DDT manual)

    IE: R 9f00 will load the hext file to A000 hex. just be sure that
    doesnt clobber anything like the existing bdos and bios.

    Then you can run with the debugger.

    Allison


  3. Re: Need CBIOS loader program

    Allison:
    Thanks for the advice. I forgot all about using DDT to load programs.
    I ORGed by test BIOS at A400 and created a HEX file.
    I found that you do not need any bias when reading a hex file to
    have it load at the ORGed address.
    For example, you can use:
    DDT TESTBIOS.HEX
    and it will load my program at A400

    or you can use:
    DDT
    -ITESTBIOS.HEX
    -R
    and it will do the same thing.
    You only need the bias in the Read command when you want
    to load it at an address other then the ORGed address.
    After it is loaded, I just type -GA400 to Goto the start of the
    program.

    Thanks again
    Old-Timer (John)


  4. Re: Need CBIOS loader program

    On 28 Feb 2006 16:34:31 -0800, "Old-Timer" wrote:

    >Allison:
    >Thanks for the advice. I forgot all about using DDT to load programs.
    >I ORGed by test BIOS at A400 and created a HEX file.
    >I found that you do not need any bias when reading a hex file to
    >have it load at the ORGed address.
    >For example, you can use:
    > DDT TESTBIOS.HEX
    >and it will load my program at A400
    >
    >or you can use:
    > DDT
    > -ITESTBIOS.HEX
    > -R
    >and it will do the same thing.
    >You only need the bias in the Read command when you want
    >to load it at an address other then the ORGed address.


    Occasionally I'd load other stuff and piece it together so the load
    address is not always the hex address. Most common use was
    segements of code all destined for a common Eprom.

    >After it is loaded, I just type -GA400 to Goto the start of the
    >program.


    You got it. I haven't used DDT in a while so I'd forgotton
    the fine details. One thing for DRI, while CP/M distributions were
    often sparse everything you needed to develope code was there.

    Allison

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