Posted By
Csabo
on 2024-09-09
11:55:25
|  Re: CASCADE (1982) and FRUIT HOOT.
Can you suggest a BASIC2 test that tells a program if it is running on a c16/plus4?
Well, the first thing I would suggest is NOT to do this  Since your ZIP file already contains a dedicated file for the C16, that one should be targeting the C16/Plus4, no detection needed.
Otherwise, this is from the startup program of The Hulk, which is official CBM software from 1984 (it checks the reset vector):
40 B=PEEK(65532)+256*PEEK(65533)
50 A$="SAGA.TED":IFB=64738 THEN A$="SAGA.C64"
60 LOAD (A$),8,1
This isn't 100% reliable either though, someone could have a custom cartridge which changes those values. I would personally check for the presence of a TED. One possible way to do it is:
T = 65303 : POKE T, 0 : IF PEEK(T) >= 128 THEN ?"TED"
This relies on the fact that the TED color registers will always have the highest bit set.
it works in winvice
There's your problem VICE is the bane of the Plus/4 scene. The problem is, because the C64 emulation is so good and VICE is so widespread, people assume the Plus/4 emulation must be equally good. Unfortunately it buggy, basic, and it hasn't been updated in years - and it likely won't be, because the actual Plus/4 emulators (YAPE, Plus4EMU) are so good, it would be a monumental effort to get it to that point.
To see what I'm talking about, open Wizard Of Wor Classic or Plus/4 XL in VICE.
In addition, the code only works by random chance. In VICE, go to settings / Machine / RAM and set the start up values to zero, you will see that it fails.
all other CBM computers by default will have rom there, not ram..
Yeah, the Plus/4 is unique in this regard. Above $FF40 there's a tiny slice of RAM which can be (and often is) freely used. |
