Jump to content
IGNORED

How did the Supercharger make graphics better?


Velvis
 Share

Recommended Posts

Individual cartridges did in fact add additional RAM, namely the Sara Superchip used in games like Secret Quest and Dark Chambers, which added an additional 256 bytes of RAM.

More RAM = more detail, more game that can be displayed at the same time. The 2600 only had 128 bytes of RAM. The Supercharger added
6 KB.

Link to comment
Share on other sites

Individual cartridges could use the same (or similar) technology- there is a Rabbit Transit prototype cartridge out there- the advantage with the supercharger was cost. A cassette tape was cheaper to produce than a special cart with extra RAM chips. As to how it worked to make better graphics, I don't know but I'll be reading the replies to find out. Edit: Butt Rogers beat me to it.

Edited by toiletunes
  • Like 1
Link to comment
Share on other sites

"Better" is a bit of a misnomer. They were still the same 2600 graphics: background, playfield, two player sprites, two missiles, and one ball, with the same basic limitations. The resolution wasn't any better - it didn't actually add any more objects, detail or colors. What the SuperCharger allowed, was for the 2600 to draw its graphics more efficiently, so they could be used to the best effect. Reusing the player sprites more, to draw a complex display in Phaser Patrol. Drawing asymmetric hallways in Escape from the Mindmaster. Or repositioning the missile and ball to smooth out those hallways. Those were things the 2600 could do anyway - but they'd take up so many resources they weren't always usable in a game. You'd see them used in title screens, and once in a while in a game, but in a limited manner. The extra RAM provided the overhead to combine them and actually make them useful.

 

As mentioned, other cartridges did use extra RAM. CBS used it as a marketing tool with "RAM Plus". A number of homebrews use extra RAM. A programmer could explain the benefits much better, but I think that's the gist of it from the graphics standpoint.

 

If you run SuperCharger games in Stella with Debug Colors turned on, you can dissect how the games were put together. Enabling/disabling the various elements (players, missiles, etc) is pretty cool too, since the programmers had to get really clever with very few resources.

I always felt the SuperCharger was under-utilized. For the capabilities of it, it had relatively few games that really pushed what it could do.
  • Like 10
Link to comment
Share on other sites

Individual cartridges could use the same (or similar) technology- there is a Rabbit Transit prototype cartridge out there- the advantage with the supercharger was cost. A cassette tape was cheaper to produce than a special cart with extra RAM chips. As to how it worked to make better graphics, I don't know but I'll be reading the replies to find out. Edit: Butt Rogers beat me to it.

 

I can make Rabbit Transit carts all day long without RAM, I owned the prototype of the cartridge version. :)

  • Like 2
Link to comment
Share on other sites

If it is just more memory how does that make the graphics better?

 

and why couldn't individual cartridges use the same technology to make better looking games?

 

 

More ram allows more computations on the graphics.

 

Also I believe Supercharger came out before most enhanced cartridge schemes did-- It was much cheaper to publish games on cassette than it was to publish them on enhanced cartridges in 1982. You just bought one enhanced cart (the supercharger itself) and cheap games.

Link to comment
Share on other sites

A cassette tape was cheaper to produce than a special cart with extra RAM chips.

 

 

 

It was much cheaper to publish games on cassette than it was to publish them on enhanced cartridges in 1982. You just bought one enhanced cart (the supercharger itself) and cheap games.

 

I'm going back about 35 years or so - if memory serves the Superchager with the pack-in Phaser Patrol cost in the ball park of $60 and the games were in the range of $12-$15.

  • Like 3
Link to comment
Share on other sites

I have a feeling (although not backed up by more than superficial debugging of some SC carts) that self modifying code may be one distinctive advantage of SC games: everything lives in RAM anyway, so the code can easily patch itself at runtime. For example, this permits to patch memory locations and data values directly into kernel code, and this allows tighter timing (more updates per scanline), similar to what data fetchers in DPC and DPC+ allow. This can be done with extra RAM (or even RIOT RAM) too, and some advanced games do it, but resources are much more scarce and it requires copying the relevant kernel code to RAM at runtime first.

Edited by DirtyHairy
  • Like 1
Link to comment
Share on other sites

Yup, self-modifying code helps the SuperCharger games.

 

The main problem of the SC is, that writing to RAM is tedious and slow. You soon run out of CPU time if you want to update a lot of RAM. Probably that's the reason why takes a few frames at the beginning of Starpath's Frogger until all rows are filled.

  • Like 1
Link to comment
Share on other sites

A programmer could explain the benefits much better,...

Not that much. :)

 

More RAM means:

  • you can handle larger worlds with more dynamic elements
  • the display kernel can do more operations per scanline (e.g. loading graphics from a static RAM address instead of having to use slower pointers), effectively you move CPU time from kernel to code outside the kernel (a bit similar to ARM based games)
  • you don't have to save RAM by merging two or more variables into one RAM variable (using different bits)
  • self-modifying code (lot of extra RAM games use ZP-RAM for kernel code)
  • ...

But resources of the 2600 are always scarce. Once you have a lot of RAM available, you soon miss CPU time to fully utilize it. Here the SC with its slow RAM access suffered most. And that's one reason why ARM based games can look so much better.

Edited by Thomas Jentzsch
  • Like 1
Link to comment
Share on other sites

I'm going back about 35 years or so - if memory serves the Superchager with the pack-in Phaser Patrol cost in the ball park of $60 and the games were in the range of $12-$15.

 

That sounds right to me ... I didn't have one when it was new, but I recall the FAQs around Stella Gets a New Brain.

 

The Supercharger is a bit like the Sega 32X or the N64 Expansion Pack, in that you buy the add-on hardware ONCE and reap the benefits on standard priced (or in the case of the tapes, cheaper) software. Unfortunately, these add-ons always seemed to arrive too late to avoid splintering the market, so the cartridges with extra hardware inside (Virtua Racing, StarFox, Doom) sell better than the games that require an add-on.

 

I love the theory, though. Boost your system and play more, cheaper, better games! I also really enjoyed converting VCS ROMs with BIN2WAV and loading them up from a PC's audio cable.

Link to comment
Share on other sites

 

The Supercharger is a bit like the Sega 32X or the N64 Expansion Pack, in that you buy the add-on hardware ONCE and reap the benefits on standard priced (or in the case of the tapes, cheaper) software. Unfortunately, these add-ons always seemed to arrive too late to avoid splintering the market, so the cartridges with extra hardware inside (Virtua Racing, StarFox, Doom) sell better than the games that require an add-on.

 

 

Yes, and it didn't help any that Supercharger was a third-party product and not an official add-on, unlike the 32x or Sega/Jag CD, etc.

Link to comment
Share on other sites

Yes, and it didn't help any that Supercharger was a third-party product and not an official add-on, unlike the 32x or Sega/Jag CD, etc.

 

 

Also, it wasn't a complete add-on, either. You still had to have a cassette player. Sure - they were common enough, but it was one more thing to have around in order to play just one SuperCharger game. And it introduced load times to the 2600, too. I found I really had to want to play one of their games to go through the extra steps. If they'd been able to lock down the rights to a few more arcade titles, maybe they would've stuck around a little longer.

Link to comment
Share on other sites

 

 

Also, it wasn't a complete add-on, either. You still had to have a cassette player. Sure - they were common enough, but it was one more thing to have around in order to play just one SuperCharger game. And it introduced load times to the 2600, too. I found I really had to want to play one of their games to go through the extra steps. If they'd been able to lock down the rights to a few more arcade titles, maybe they would've stuck around a little longer.

 

True. They did produce a much superior version of Frogger, but how many people felt they needed Communist Mutants from Outer Space in their life enough to buy all that.

 

And yeah, I remember that playing cassette games on my Atari 600XL required a commitment too, so I can see that being a supercharger issue.

Link to comment
Share on other sites

 

True. They did produce a much superior version of Frogger, but how many people felt they needed Communist Mutants from Outer Space in their life enough to buy all that.

 

 

I tell you what - I had Phaser Patrol, Frogger, Commie Mutants, Mindmaster and Fireball (or whatever TF it was called) and I thought they were all high quality games when you stack them up to other games being released in that time period.

  • Like 1
Link to comment
Share on other sites

I remember buying a stack of Supercharger games at Toys R Us right after the "crash" for like $2 each. I couldn't have been happier. Some of the games like Phaser Patrol, Mindmaster and DragonStomper were amazing! I had them all except Frogger and Rabbit Transit.

Link to comment
Share on other sites

I only have a loose cassette of Dragonstomper, but it's such a neat game! :D

 

Well worth me setting up the Supercharger to go on an adventure.

 

The Multi-Load nature of the Supercharger was another neat thing I thought brought about some added robustness to the games. It added load times, but you got to have such a bigger game comparatively speaking. That part didn't necessarily make the graphics better, but more variation was appreciated. :)

Edited by Jinroh
Link to comment
Share on other sites

 

  • self-modifying code (lot of extra RAM games use ZP-RAM for kernel code)
  • ...

 

That's interesting :) I would have expected games to use the extra RAM for kernel code and reserve ZP RAM for data (due to the cycle savings during access) and for indexed indirect adressing.

Link to comment
Share on other sites

SuperCharger RAM isn't that slow. I don't see a significant difference in access times between cross compiled Flashback BASIC games and their SuperCharger counterparts, even with games that utilize nearly all the time in both vertical blanks to update most of the screen (playfield and sprites) every frame.

 

It would be interesting if anyone wants to check the cycle counts in the debugger to konw for sure - the version of WARPDRIVE on my site uses CBS RAM internally while the one below uses SuperCharger RAM, the rest of the code is the same.

 

http://atariage.com/forums/topic/267146-supercharger-audit/?p=3799657

 

You have to throw the black and white switch (Warp engines) while you're playing the game to get a full load on the vertical blanks every frame.

Link to comment
Share on other sites

SuperCharger RAM isn't that slow.

 

With "ordinary" extra RAM (including CBS), you just have a STA / STX / STY to store data, and that's between 4 - 6 cycles. With SC RAM, you have an access to 0x10xx to queue the value you want to write, then 5 bus transitions delay (that's at least 5 cycles), and then an access to the address you want the data to be written to. Together with an absolute / absolute indexed access for the first access, that makes 9 cycles, so the difference is 3 - 5 cycles for each access. Whether that's a problem or not depends on what you want to do :)

  • Like 1
Link to comment
Share on other sites

 

With "ordinary" extra RAM (including CBS), you just have a STA / STX / STY to store data, and that's between 4 - 6 cycles. With SC RAM, you have an access to 0x10xx to queue the value you want to write, then 5 bus transitions delay (that's at least 5 cycles), and then an access to the address you want the data to be written to. Together with an absolute / absolute indexed access for the first access, that makes 9 cycles, so the difference is 3 - 5 cycles for each access. Whether that's a problem or not depends on what you want to do :)

 

You're right on both counts - the difference is significant and adds up for every byte you update, but it depends on what you do with it. With a soft blitter the difference is minimized because the total extra cycles get divided by 8 from the blitting.

 

With that in mind recompiling SuperCharger games to CBS RAM should never be an issue - there's plenty of time, but an over cycle break would show up in the other direction if someone used all of those extra cycles to create a Flashback BASIC game and then recompiled it for the SuperCharger. I'd like to get the compatibility 100% across both memory access schemes but differences like this make it challenging.

Link to comment
Share on other sites

Whether that's a problem or not depends on what you want to do :)

True. If you only use the SC-RAM for additional variables or self-modifying code, then those extra cycles don't hurt much. But if you want to utilize a lot of RAM, e.g. for larger dynamic arrays (e.g. for sorting) or for something like a (scrolling) screen buffer, then you want the code to be as fast as possible.

 

So even though the SC offers 6K of extra RAM, most of it can only be used as a ROM replacement. It is not like you have 48 times more RAM available. IMO less extra RAM but faster access (e.g. like E7) is usually the better alternative

  • Like 1
Link to comment
Share on other sites

How did the Supercharger make music better?

 

Supercharger unreleased 1983 prototype Sweat has 2-channel, in tune music produced similar to how Pitfall 2 did with its DPC chip--vibrating the Volume register to produce pure tones. Not done again until Stella's Stocking 4-channel software only feat, and Stay Frosty 2 with the DPC+ music routines.

 

So this is nice to hear since we just had the 4th of July / Independence Day in the USA and this song is The Star Spangled Banner.

Just run the zip, or the 1 of 3 file.

 

sweat.zip

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...