Re: SEGA's arcade rendition of CHOPLIFTER my favorite 8-bit game as of late

["Michael J. Mahon" <mjmahon@aol.com>]

BluPhoenyx wrote:
> Larry Stedman wrote:
>
> > Bill, they're the ones on the various Apple II sites...  I Googled 
> > choplifter.dsk and came up with several.   That's the easiest way to 
> > get them directly.  I keep looking for a "choplifter_IIc.dsk" or some 
> > such but no luck.
> >
> > I put some of the games on a 3.5" disk, but the //c balked at booting 
> > the disk because it said no ProDos, then once I had put ProDos on, it 
> > booted, but when I tried running any of the binary game files, the //c 
> > responded with "NO BUFFERS" and refused to run the programs.  Perhaps 
> > it needs to run under Dos 3.3, from a 3.3 formatted diskette, which is 
> > what I presume the 5.25" diskettes are.
> >
> > Anyone know what the NO BUFFERS means?  Is that an OS issue or a //c 
> > issue?  Is there a way of creating some buffers?  :-)
>
>
>
> This is a general error message for whenever BASIC.SYSTEM cannot load to 
> certain memory locations. It is triggered by several things. One is the 
> location of HIMEM which can be set in BASIC. Also BASIC.SYSTEM has a 
> routine to allocate 512 byte blocks from assembly. IIRC, this still 
> requires you to set the actual HIMEM location.

Actually, it allocates 256-byte pages.  BASIC.SYSTEM sets HIMEM when
you allocate space in this way.  It also dynamically moves HIMEM as
files are OPENed or CLOSEd.

> It may also be generated when attempting to load a file into P8 
> protected ram. ProDOS uses a bitmap to know which pages of ram it can 
> use to load files into. In BASIC.SYSTEM, this is generally $800...$9600 
> (set by HIMEM). This implies both screen ram $400..7ff and above HIMEM. 
> Looking at the disk catalog, what is the program's load address and length?
>
> There are a few other things which I think generate this error but these 
> are the most common when using BASIC.SYSTEM. You might be able to load 
> the game in DOS 3.x but you should still be aware of where the program 
> loads and if it overwrites any important memory locations.

When BLOADing any file large enough to overwrite BASIC.SYSTEM, the
loading must be done by MLI-invoking code outside of BASIC.SYSTEM.

If it's a DOS-based program, then it may be dependent on DOS in any
case, so using a ProDOS-based DOS loader like DOSMaster may be the
answer.

-michael

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