> So you're doing EPROM's now? I thought most early games were produced on
> ROMs? Do you know if any commercial sold games used EPROM's back in the
> 80's?
Yes. A chip needs to be produced in the hundreds of thousands to make it
really cost effective. Since the code in a ROM is part of it's physical
structure, it has to be included as the chip is being made. Whereas an
EPROM can be programmed after the fact. I think Randy uses OTP (One Time
Programmable) EPROMs. This is a standard EPROM without the quartz window
for UV erasing. High quality quartz is expensive and adds considerably to
the cost of an EPROM. I know that several manufacturers used EPROMs. Usually
the smaller software houses that couldn't afford to have ROMs manufactered.
> Another question concerning EPROM's: Could it be that they lose their
> memory after, let's say, ten or twelve years? My Mangia and Pitfall II
> carts seem to be broken. Could this be the reason for that? (Now that's
> a case where downloading the BIN from the Internet IS legal... no?)
By all means. This is usually referred to as "bit rot". What a lovely term :)
But Activision carts are notorious for being flaky. I think the PCB material
they used was a few mils to thin. Try the following:
Plug in your Pitfall II cart, then push forward on the end of the cart while
you turn it on. If this works, you can use a Combat cart to prop it up.
(The prop wont work on a 2600 jr...no ridges for the Combat to push against)
> Could you please explain further what this (latching a console switch
> value) means?
Simply read it at powerup and store it in memory. Then you can read it from
memory when you need it, and use the switch for other things.
> And from Piero Cavina:
>
> >BTW, I haven't yet found a PAL tv which can't sync to the NTSC version of
> >Oystron, so this feature could be considered useless.. but it's great fun
> >to switch the mode on the fly, and see the TV lose sync for a couple of
> >seconds... :-)
>
> It should affect game speed too... since PAL is 50 Hz and NTSC is 60 Hz,
> it should run 20% faster on NTSC. Or did you take care of that too?
That's what's so nice about the 2600. Since you have complete control over
the vertical refresh, you set the frame rate. So if your running the same
code, the game speed will only vary as much as the internal oscillator speed.
Which according to Eckhard, is about 1%...essentilally the same.
> A few years ago, I went to a friend who also had an Amiga with some cart
> that allowed switching the output signal to 60 Hz. His Amiga 1081
> monitor synced to it, too... so I suppose mine also would. The only
> trouble could be the VCR I have to use in-between the VCS and the
> monitor, cause the 1081 hasn't got a tuner.
You really should go pull the composite signals from inside the 2600. The
improvment is awesome. And it's an easy mod to make. Then you don't have
to worry about using a VCR as a video converter.
-Chris
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