08/18/88: booting dos from disk by Delphi, | Category: Delphi - Utilities & Applications | 4 comments - (Comments are closed)

booting dos from disk

44283 18AUG88-0157 Utilities & Applications
booting dos from disk
From: KENHALTER To: ARTFLEXSER

Hi Art,
I’m having problems getting DOS 1.1 to boot from disk on my CoCo3.
It boots up fine but leaves me in the CoCo 2 mode. No CoCo3 cmds.
I saved the rom to disk when I got my new disk controller so I might be
able to use some programs that aren’t compatible with my new disk rom.
First I LOADM the rom to $6000-$7FFF. Then I use a M/L program to move it
to $C000-$DFFF. Next I try to get it up and running by EXECing either
&HA074, $8002 or $C002. Nothing seems to help. It’s stuck in the CoCo 2 mode.
Any suggestions? Ken Halter

4 comments to booting dos from disk

  • pucc_unknown

    44294 18AUG88-2212 Utilities & Applications
    RE: booting dos from disk (Re: Msg 44283)
    From: HARDWAREHACK To: KENHALTER

    Forgive my butting in….. does your boot loader disable the interrupts?
    I do exactly what you are trying to do, and it’s easy. Be sure that you
    use a COCO-2 or a COCO-3 in the ROM mode to do the inital save of the
    ROM to disk, since the COCO-3 patchs RS-DOS (both useless patchs). Use
    the following code to boot RS-DOS into memory: (note, I saved it from
    $2000 to $3FFF)

    BOOT CLRA SET “Z” BIT
    JSR $A910 CLEAR THE SCREEN
    ORCC #$50 INTERRUPTS OFF (ESSENTIAL!)

    LDX #$2000 POINT TO RAM IMAGE OF RS-DOS
    LDU #$C000 POINT TO WHERE IT’S GOING

    LOOP LDA ,X+ GET A BYTE
    STA ,U+ PUT A BYTE

    CMPX #$4000 ALL DONE?
    BNE LOOP NO, MOVE MORE

    JMP $C002 ALL DONE, GO THERE

    Hope this helps. (use an ORG of something like $1FE0, then LOADM
    the RS-DOS file, then LOADM the booter, then SAVEM the final file
    with SAVEM”NAME”,&H1FE0,&H3FFF,&H1FE0 ok?)

    ….Roger

  • pucc_unknown

    44301 19AUG88-0046 Utilities & Applications
    RE: booting dos from disk (Re: Msg 44283)
    From: ARTFLEXSER To: KENHALTER

    The method you describe sounds fine to me. The only reason I can think of why
    you might be stuck in CoCo 2 mode is that you are also
    copying $8000-BFFF from ROM to RAM. Sure you didn’t use a routine that
    does that as well as block moving the disk code to $C000?
    (An exec of $8002 or $C002, but not $A074, ought to be okay.)

  • pucc_unknown

    44351 20AUG88-1231 Utilities & Applications
    RE: booting dos from disk (Re: Msg 44301)
    From: KENHALTER To: ARTFLEXSER

    That’s it!! I do copy the code from $8000-$BFFF. I’ll have to try it
    again. Thanks. Ken Halter

  • pucc_unknown

    44352 20AUG88-1234 Utilities & Applications
    RE: booting dos from disk (Re: Msg 44294)
    From: KENHALTER To: HARDWAREHACK

    But in all you want! Thanks for the reply. I do disable interrupts.
    But I was also copying the roms from $8000-$BFFF from rom to ram. I think this
    was my mistake.
    Thanks again. Ken Halter