I was wondering why that was done. Wow. When you finally find the answer
to some questions, it's pretty weird!
This was similar to my cart reader. But I used the load feature of the '161's
(I think I used 163's, but same thing essentially) to load specific addresses
into the counters to avoid this issue. And yes, I used Qbasic.
-Chris
On Sat, 12 Mar 2005, Eckhard Stolberg wrote:
> >I say to keep things simple. Several years ago I made a cart reader from a
> > 555, three 7LS161's and a 7400 NAND gate chip. I connected this to the
> > parallel port of a PC and wrote some code using QBASIC, hey it was what I
> > had. The 555 was set up as a one shot and was reset from one of the
> > signal
> > lines from the PC port, this was how I synced the PC to the cart reader.
> > Using this I ws able to dump the ROMs for Sir Lancelot and Moon Sweeper.
> > At
> > the time the ROM image floating around for Moon Sweeper was only 4K, it is
> > a
> > 8K game and some folks were looking for Sir Lancelot. I can't remember
> > the
> > details, I will have to check my old PC to see if the program is still on
> > it. It was nothing fancy but it worked.
>
> Unfortunately that's a bit too simple for bankswitched games.
> With this method you would always access all bankswitching
> hotspots in a row. So the data after the hotspot addresses will
> always be read from the last bank. In fact we had to add a special
> bankswitching mode to z26, because people kept complaining about
> these two ROMs. ;-) The games couldn't be started in the first bank,
> because the system vectors were read from the second bank. So we
> had to add a special bankswitching mode for these two F8 games
> were the game gets started in the second bank.
>
>
> Ciao, Eckhard Stolberg
>
>
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