Re: Choplifter, still no go on Apple IIc +

[mdj <mdj.mdj@gmail.com>]

On Jun 21, 2:18 pm, Polymorph <polymorp...@hotmail.com> wrote:
> On Jun 21, 2:00 pm, mdj <mdj....@gmail.com> wrote:
>
>
>
> > On Jun 20, 7:46 pm, Linards Ticmanis <ticma...@gmx.de> wrote:
>
> > > Polymorph wrote:
> > > > I don't have a //c or //c+, but that image that Bill posted works fine
> > > > on my ROM03 IIgs, so there must be some incompatibility specific to
> > > > the //c+ (maybe even the //c?). Do you have problems with any other
> > > > programs/games on your //c+?
>
> > > Hmmmm... are there any Soft Switches or hardware registers peculiar to
> > > the //c+ ? Mabye one of them gets hit by accident in this game?
>
> > > Or maybe this has to do with interrupts? Interrupts normally occur in a
> > > //c but not in a //e, right?
>
> > I can confirm choplifter works just fine on a ROM04 //c, which pretty
> > close to a IIc+. Since interrupts are probably disabled during the
> > game anyway, I'd imagine it's some incompatibility with the
> > accelerator hardware. I assume you guys are testing this with the
> > accelerator disabled ?
>
> > This is going to one of those problems where finding the culprit is a
> > bit like looking for a tiny piece of hay in a massive stackful of
> > needles. The solution once it's found, is probably trivial.
>
> > Matt
>
> Matt,
>
> I ran Choplifter on my ROM03 IIgs with a Zip GSX installed - but with
> the control panel speed set to "normal" (ie. 1Mhz). I don't know if
> this has any relevance to the //c+ though? I thought it might, as
> isn't the //c+ accelerated by an onboard ZIP chip? I can try running
> it with the Zip GSX enabled, however, it will be pretty freaky trying
> to play the game running at 8Mhz.  ;-)

Yeah - the IIc+ has the equvalent of a 4Mhz Zip Chip installed, but
it's implemented with a 4Mhz 65C02, ASIC, and seperate SRAMs for the
cache. Apparently Apple believed that the integrated chip as shipped
by Zip would be unreliable. Since I've had one die on me, I tend to
think they may have had a point.

> As a side note: I'd never even heard of a //c+ until last year when I
> returned to toying with my A2 after 15 years (I don't think the //c+
> ever made into Australia, except maybe via direct individual
> imports?).

Yep, US market only. It was really intended to offer a competitor to
the Laser 128/EX, which was both cheaper and more feature rich than
the original //c.

> Anyway, over to you guys with the //c+ 's... hope you get it sorted
> out.  :-)

Unless there's an errata list for known Zip anomolies, it seems
doubtful. I know that Publish It! used to trigger a Zip bug, and later
Zip's were modified to work around it.

Matt