[Coco] Kinda disappointed with 6809 assemblers

[Steve Bjork]

Try this to define the Index into the object (DataBlock.)

             org       0         ;Game object
octrl    rmb      1         ;Control Byte
xpos    rmb      2         ;16-bit x position
ypos    rmb      2        ;16-bit Y position
olen     equ       *        ;PC counter is the length of the object
....

             org        0        ;Sound Object
sctrl    rmb      1        ;Control Byte
spnt    rmb       2       ;Pointer to next digital byte to output
scnt    rmb       2       ;# of bytes left to play
slen     equ       *       ; PC counter is the length of the object.

Just do the above before the start of the program.

Steve

On 1/31/2013 9:37 AM, Luis Antoniosi (CoCoDemus) wrote:
> mega ROM files. When using mega-rom paks, with multiple pages like a MMU
> switched by a bank register, you need to distribute your data between the
> bank pages, and therefore you need to fill the gaps with some value. Just
> ORG won't work there.
>
> I do agree for binaries loaded from disk this would be wasteful as you just
> need rmb at the end of your code segment instead of fcb.
>
> But this is just one of the things that 6809 asm lacks. Other is being able
> to resolve labels and offsets in the second phase. But I kinda understand
> why this wasn't needed in first place: 6809 can generate native relocatable
> code while z-80 must rely on code offset arithmetic to be able to emulate
> such thing.
>
> But my major complain the what operators you can use to calculate immediate
> values.
>
> Felipe.
>
>
> On Thu, Jan 31, 2013 at 12:21 PM, Steve Bjork <6809er at srbsoftware.com>wrote:
>
>> The reason why better assemblers don't include a fill a block of memory
>> option is its wasteful.
>>
>> While it make it easier to write the source code with a memory "init" at
>> run time by loading in all that data, it waste space in the run-time file
>> that's loaded.
>>
>> In the days when file space could not be wasted for 256 zeros, it was
>> better to reserve the space in memory for the data and at run-time to clean
>> it out with a few lines code. (It goes without saying that code running in
>> ROM would have clear it at run-time.)
>>
>> Too many times I've seen code create by young programmers with megs and
>> megs of array data fill with none thing but zeros.  Once I got a programmer
>> to see the errors of his ways, the Game Install CD-ROM dropped from three
>> to just one.  (The savings in production cost more than paid for the
>> consulting fees for that project.)
>>
>> Yes, you can pack (zip) the file to remove most the wasted space. But why
>> have the wasted space in the first pace?
>>
>> Steve
>>
>>
>>