Toyshop Trouble is brilliant!

#176 supercat OFFLINE

Quadrunner

6,367 posts

Posted Tue Aug 28, 2007 8:36 PM

batari, on Tue Aug 28, 2007 7:40 PM, said:

Quote

Hmm... actually, I might be able to manage it without excessively-floated capacitors, but it'd probably require too many resistors to be very nice. Thinking... Hmm... that might work.

I thought about this too, but more as a good way to support LARGE carts. E.g. if you use a 22v10 PLD instead of the TTL chip in the 8k version, you might have enough macrocells to support a 32-pin EPROM, i.e. 128k, 256k, 512k, or maybe even 1M?

Even a lowly 16V8 would have no problem supporting a 64-bank scheme with 08xx hotspots. A 22V10 could push it up to 256 banks. That would be a megabyte worth of code. The same result could be achieved using two common TTL chips (a 74HC00 and a 74HC373, or any of many other combinations). The advantage of 0840 is that it doesn't require programming a PLD before assembly.

I'm working on a number of projects so I don't want to keep grabbing more, but adding EEPROM to a 2600 cart would not be particularly difficult, though there would be a tradeoff between ease/speed of programming and complexity. One approach I started on would allow data to be read or written from the I2C very quickly. To write:

  nop $0800,x
  nop $0900,x
  nop $0A00,x
  nop $0B00,x
  nop $0C00,x
  nop $0D00,x
  nop $0E00,x
  nop $0F00,x
 ; Then to test the acknowledge:
  lda $1FF0 ; Zero if ack, or 128 if nak

to read:

  nop $0800; If needed to ack previous byte
  lda $1FF0
  ora $1FF1
  ora $1FF2
  ora $1FF3
  ora $1FF4
  ora $1FF5
  ora $1FF6
  ora $1FF7

Running things that fast would require using a 'FC'-series EEPROM, but one could do a lot with a 36 cycle/byte read and write speed. Considering that's two bytes/scan line, it may even be possible to do some things mid-kernel (with the unfortunate caveat that writing data to the chip will make it inaccessible for about half a frame).

#177 supercat OFFLINE

Quadrunner

6,367 posts

Posted Tue Aug 28, 2007 9:08 PM

batari, on Tue Aug 28, 2007 7:40 PM, said:

True, though at this point I'd be surprised if anyone has bothered to take apart a TT cart, pull the EPROM and dump the binary with an EPROM burner, or hack the 7800dev software to dump 0840 or whatnot, as they can't play the binary in an emulator, Kroko or Cuttle Cart. Releasing the emulator support might encourage one to do so, but I wonder if it would happen and be widely disseminated before you release the binary, if you're doing so early next year (and if that binary release is going to be 0840 or F8.)

Fair 'nough. And actually, if someone had a copy of the 0840 ROM it wouldn't exactly be hard to convert to F8 banking. Indeed, most of my testing was done using F8 since my 0840 prototype cart was rather dodgy. Had that not been the case, I would have had an extra four bytes of code space to play with (though that would have broken F8 banking).

#178 Deteacher OFFLINE

River Patroller

2,285 posts

Location:Newark, DE

Posted Sat Mar 8, 2008 3:55 PM

Just received TT in the mail and I couldn't wait to try it out! After playing a few rounds (besides my hand cramping up) I have to say this is one of the best games ever made for the VCS! Everything about it is simply fantastic! The music is awesome, especially how the tune goes into a minor key when the game's over. Also, I love the "colored organ" effect on the title screen.

Gameplay is simple, yet VERY challenging. The difficulty ramps up at a nice gradual pace. It's just right, IMO. It plays a lot like pressure cooker (as was mentioned in an earlier post.)

I can't find a single negative thing to say about this game. Kudos to everyone involved with it's creation!

If you are looking for a homebrew to purchase, don't hesitate to pick up Toyshop Trouble. You won't regret it!

Now, I'm off to try to find the easter egg(s).