I've been ever so slowly trawling thru my games collection - mostly commercial C64 games.

Almost all work fine on the 128, but I've noticed that Hacker will not load on the 128 in 64 mode.

So I did a test with a C64.

Naturally, it loads fine on a 64 & 1541. But, a 64 & 1571 fails. I'm guessing this is due to the 71 not being entirely compatible with the 41.

I don't have a flat C128 so can't test against it with a 1541 & 1571, but I'm guessing the same will happen.

Anyone aware of any others that fail ?

Brendon

How did you enter 64 mode? I seem to recall that some programs wouldn't load properly if I'd used GO64, but worked fine if I had entered 64 mode by holding down the C= key during boot.

OK deleted that bit of cobblers I wrote a few minutes ago .. what the 1571 manual says on the subject is :

", the 1571 powers up in 1541 mode.  However, it automatically shifts to 1571 mode upon the first of a fast serial transfer initiated by the host (the Commodore 128)."

So to me that means that if you have a 1571 plugged into a C128 and you start the C128 up in 128 mode then the 1571 will shift to 1571 mode (because of that autoboot thingy the C128 does, which is done using "fast serial"), then if you do a G064 the 1571 will still be in 1571 mode.  I guess if the C128 is then started in 64 mode (by holding down the C= key) the 1571 would stay in it's 1541 mode (because the 64 doesn't have an autoboot thingy and does not use Burst mode).

I guess there still might very well be some apps and games that can give grief on a 1571 due to fast loaders and the like.

At some point I either found in a magazine or on Quantum Link a utility that let the 128 in 64 mode take full advantage of the 1571's burst mode. It was hopelessly incompatible with most commercial games, but it worked wonderfully with one of the BBS programs I used.

I know that there is a certain memory location that is actually used differently between a real 64 and the 64 mode on the 128.  This is how you can tell if you are running on a 128 or a real 64.  Maybe Hacker uses this location for some reason (not sure why - as I understand, the real 64 just shadows this location and it serves no meaningful purpose).  I havent tried this, so Im not sure if its the issue, but I remember reading about it.  Very few games were affected by this issue, not sure if Hacker was one of them.

Quote from: xlar54I know that there is a certain memory location that is actually used differently between a real 64 and the 64 mode on the 128.  This is how you can tell if you are running on a 128 or a real 64.

I'm not familiar with this memory mode.  I figured people just tried to access the VDC.  if it worked, you're on a 128.  I wrote a C64 program once that did this.

I think the usual way is with $D02F, which always contains $FF on a real 64 no matter what you write to it. On a 128 in 64 mode, however, it can be changed.