Re: [cc65-devel] Binary loads of overlays on various targets

[Oliver S. <ol...@we...>]

Hi,

> The overlaydemo.c and multidemo.c load overlays with open/read.  These would
> use CIO/SIO on the Atari which by default is “fast”.  You also don’t need to
> have any load address in the file, and if you did, you’d have to write code
> to handle it yourself.

@Shawn: Thanks for filling in the missing info :-)

> I already know that the best way to load
> the overlays on the two Commodores is through the CBM_LOAD command which
> will allow fast-loaders to load the files.

I'd like to better understand this:

The CBM implementation of read() loops for each byte over calls to
BASIN and READST. I see that this isn't going to be exactly fast ;-)

The implementation of cbm_load() on the other hand just calls (SETLFS,
SETNAM and) LOAD.

I'd appreciate if someone could give me some rough estimates about
relative performance of these scenarios just to provide me with an
idea of what we're talking about here:

1. read() with "default DOS" (let's define this as performance of 1.0)
2. cbm_load() with "default DOS".
3. read() with fast-loader.
4. cbm_load() with fast-loader.

Thanks in advance for your help!

Regards,
Oliver