Atari 7800 VS Epoch Super Cassette Vision

[sd32]

How about this one, the 7800 Vs the original competition for the NES in Japan, i am talking about the Epoch Super Cassettevision. I guess most people here dont know much about it so here are some links with info, screenshots:

http://www5e.biglobe.ne.jp/~kiden/supakase.htm

http://homepage3.nifty.com/doritomo/game/Scv/SCV-3.htm

http://www.game-nostalgia.net/scv/scv.htm

http://www2.odn.ne.jp/~haf09260/Scv/EnrScv.htm

http://www1.interq.or.jp/~t-takeda/top.html

http://en.wikipedia.org/wiki/Super_Cassette_Vision

I dont know much about interpreting specs so reading them on Wiki doesnt do much for me, but from the games i have played i would say that it is similar to the 7800 in that it appears to me, to be better at moving many objects on a single screen, rather than at doing games that are heavy on scrolling (NES type).

In the games i have, scrolling is sometimes a bit jerkier than what you would usually see on NES but quiet better than say, MSX. But on the other hand, the Galaga clone called Astro Wars: Battle in Galaxy, is really fast with some pretty interesting enemy patterns, its really good. Also, the into the screen racer Star Speeder is very impresive with very fast action, but has little background detail.Another thing in wich it its similar to the 7800 in that it uses the same sound chip from its predecesor, the original Cassettevision just as the 7800 uses the one from the 2600. So both are quite inferior to the NES when it comes to sound. One final caracteristic that it shares with 7800 is that usually its carts were also smaller than your average NES carts, apparently Epoch also was pretty cheap like Atari, or simply didnt have the resources.

Games that appeared on both the Super Cassette and the NES usually look better on NES. Like Mappy, Pops and Chips, Sky Kid. But the Super Cassette ports are still pretty good, not bad at all.

I think the only game that it shares with 7800 is Pole Position 2, but i havent played the Super Cassette version, nor have i seen decent screenshots of it to do a good comparison.

So can anyone here can talk a bit more in depth about this japanese console?, i am not a coder so i dont know too much about hardware specs.

Edited August 17, 2008 by sd32

[games-video]

Epoch Super Cassette Vision was the first system on which a battery-backed up cartridge appeared (Dragon Slayer), pre-Zelda, and pre-Phantasy Star.

[Vic George 2K3]

Hard to do a comparison when you can't find any good pages with big-enough screenshots for the games.

[Vigo]

I have never heard about that system. But the specs surely are less than impressive...

[sd32]

Yeah, its pretty obscure so its pretty hard to compare with.

The system was also released on Europe by Yeno, with about half the games released on Japan. It failed on both markets.

Its also interesting to point out that it included an RGB conection, must have been pretty rare for a console back on 1984 when it was released.

The specs are:

CPU: uPD7801G (NOT Z80 Clone) 4 MHz

VDC EPOCH TV-1 14.31818MHz

RAM: 128B (uPD7801G internal)

ROM: 4KB (uPD7801G internal)

Video Processor: EPOCH TV-1

VRAM: 4KB (2 x uPD4016C-2) + 2KB (EPOCH TV-1 internal)

Colour: 16

Sprites: 128

Display: 256x256

SOUND G UPD1771C 6MHz

Sound: 1 channel (Tone, Noise or 1bit PCM)

Controllers: 2 x hard-wired joysticks

Vigo, judging by the specs, would you say its weaker than 7800?

Oh, and here is another SCV link:

http://www.rhod.fr/yeno_epoch.html

Edited August 18, 2008 by sd32

[DracIsBack]

Vigo, judging by the specs, would you say its weaker than 7800?

 

"Stronger or weaker" and "Less powerful or More Powerful" are simplistic conclusions to a complicated question.

[Vigo]

Vigo, judging by the specs, would you say its weaker than 7800?

 

"Stronger or weaker" and "Less powerful or More Powerful" are simplistic conclusions to a complicated question.

 

I'm a bit confused about the specs, because there is practically nothing really documented (even the CPU, though normally, a NEC uPD780 is a Z80 clone), and some specs seem a bit unorthodox (128 Sprites??? As much as the SNES? I doubt it.), especially when looking at the screenshots. Plus, I never used or saw one in real life. Very interesting though.

Edited August 18, 2008 by Vigo

[sd32]

Yeah, specs found on the web seem kinda incomplete. Its mentioned 128 sprites, but what size, colors?

From the games i own (Kung Fu Road, Doraemon, Battle in Galaxy, Punch Boy and Lupin 3rd) i would that it is definitely in the same group with 7800, C64GS, NES, etc. It came out in 1984 after all, so it better did!

[Artlover]

Yeah, those specs are very incomplete. Can't find diddly squat in the way of any details. Only thing I have found is that those specs posted are from Wiki, and the scren resolution is contradicted by every other website w/specs on the thing.

 

Can't find any exact match for the CPU, but this seems like it's the same thing or atleast the same class/series. http://www.datasheetarchive.com/UPD7801-datasheet.html

 

The screen shots look ok for a system of it's time. I can only imagine they sounded like crap tho based on the sound specs.

[Rhod]

http://www.rhod.fr/yeno_epoch.html

 

hello, this is my site.

 

Yeno SCV was sell in Europe, especially in France, imported by ITMC

Games are slow, scrolling are not very good.

[sd32]

Hey Rhod, i really like your site. Have you played Wai Wai (Y2) Monster Land?. Can you comment a bit on that game. Its the only Super Mario Bros. style platformer on the system, right?, with a little Castlevania flavor on it.

[A Sprite]

Video.

 

It's like MARIA and the TMS9918 eloped, and had a love child.

 

"He's got mommy's singing voice!"

 

"That's just the dog. Bad TIA! ...is our baby having a seizure?!"

 

"Maybe we can teach him to play Moon Patrol."

Edited August 18, 2008 by A Sprite

[Vigo]

Can't find any exact match for the CPU, but this seems like it's the same thing or atleast the same class/series. http://www.datasheetarchive.com/UPD7801-datasheet.html

 

Seems to be a Z80/8080 based microcontroller architecture, although the mnenomics differ a bit from the Z80. The register architecture, and how they are used for addressing, seems to be the same.

[TAKEDA, toshiya]

Dear members,

 

My name is TAKEDA, toshiya.

I am the developer of Super Cassette Vision emulator.

http://www1.interq.or.jp/~t-takeda/scv/index.html

 

This comment except CPU is the result of reverse-engineering

by I and Mr.Enri (http://www2.odn.ne.jp/~haf09260/Scv/EnrScv.htm)

and is not authorized by any official documents.

But I believe it is not wrong because my emulator looks working fine.

 

Well, I once wrote the technical information about this console.

http://www1.interq.or.jp/~t-takeda/scv/scv.pdf

It is written in Japanese, but you can refer some pictures in it.

 

-----

 

CPU)

 

NEC uPD780C1 is a well-known Z80 clone CPU, but it is NOT the CPU of this console.

NEC uPD7801G is the first CPU of uCOM-87 series.

It is the old single chip CPU with internal 4KB ROM, 128B RAM and some I/O ports

for embedded market and was used for example as the controller of printer device.

 

It has the instructions like 8080 and a couple of registers like Z80,

but also has the unique condition instructions.

8080 and Z80 have the instructions to branch in the condition of previously

executed instruction, for example jump if zero,

uCOM-87 has the complex instruction, operate values of registers

and skip next one instruction in the condition for example

ADDNCX A,reg: A <- A + [reg], and skip next instruction if non carry.

 

This CPU has many other unique and complex specifications.

I could not find the datasheet of uPD7801G, but you can find uPD78C10

in www.datasheetarchive.com/

It is also one of uCOM-87 family and very similar to uPD7801G.

(A/D converter and some 16bit operation instructions are added.)

 

 

Video Controller)

 

The custom LSI called "EPOCH TV-1" is the video controller.

It is said it was designed by NEC.

 

It supports 128 (really 128!) monochrome 16x16 sprites and Text/BG screen.

I could not clarify how many sprites can be displayed in one line,

but another analyzer called Mr.333 said it is 30.

It does not support the sprite collision checker, so each game must refer

and compare the sprite attributes (locations) to check collisions.

 

There are a couple of 2KB SRAM chip (uPD4016C-2) on the main PCB

and they are connected to this video controller, not to CPU. (*)

These SRAM are probabbly used for the pattern of sprites.

And EPOCH TV-1 has probabbly also 2KB and more RAM in the package

for Text/BG screen VRAM and the sprite attributes.

There are 128 blocks of 4byte sprite attribute for the pattern number,

locations(X/Y), colour number and some additional bits.

 

(*) This means almost games use only 128B RAM in CPU to control the game.

Some games for example SHOUGI NYUUMON (Japanese Chess), BASIC NYUUMON

and Dragon Slayer, have external 8KB SRAM on their cartridge PCB.

It is used for the work memory and also the buttery-backuped RAM.

 

This chip has vsync signal and is connected to the interrupt of CPU.

uPD7801G can detect the interrupt by both edges Low->High and High->Low

and the interrupt occurs twice for one video frame.

 

 

Text/BG screen)

 

EPOCH TV-1 has one Text/BG screen.

We can divide one screen to 2 areas for text and BG.

Considering the VRAM size, the screen size must be 256x256, NOT 309x246.

But the resolution really displayed on the TV monitor seems to be about 192x222.

(In the case Japanese NTSC TV monitor, I dont know PAL case.)

 

In the text screen, the text characters are displayed only by writing the codes to VRAM.

It is same as the old computers' text screen for example Apple][.

The character pattern must be registerd in EPOCH-TV1, no character ROM is on PCB.

The character and backgroud colour can be specifyed only for whole of screen,

we cannot specify different colour for each character.

 

In the BG screen, there are 2 modes:

- 32x32 low resolution/16 colour mode

- 64x64 high resolution/monochrome mode

 

In the low resolution mode, the size of one pixel is 8x8 dot

but the different colour can be specified for each pixel.

This mode is mainly used for the multi color back ground.

(Because only one colour can be specified in the text screen.)

Please refer page 7 in my technical document.

In Lupin 3rd, the sky colour is set to light cyan, the sewer is set to blue.

 

In the high resolution mode, the size of one pixel is 4x4 dot

but only one pair of dot/bg colour can be specified for whole of screen.

Please refer also page 7 in my technical document.

In Star Speeder, the line of the road are displayed with this mode.

 

 

Sprite)

 

It supports 128 sprites, and they are divied to 2 gruops for the purpose.

The sprites no.0-31 and 64-95 are for the back ground for example the floor,

And no.32-63 and 96-127 are for the moving obect for example hero and enemies.

The differences are the meanings of additional attribute bits.

 

For the back ground sprites, the connection function is supported.

The sprite size is 16x16, but another sprites can be connected at the right and bottom

and we can display 16x32, 32x16 and 32x32 sprite only specifying one attribute block.

Please refer page 8 in my technical document.

The title screen of Elevator Fight is displayed by this connection function.

 

For the moving sprites, the 2-colours sprite and the division function are supported.

2-colours sprite are realized by putting another pattern and colour sprite upon

off course by spcifying only one attribute block.

Please refer also page 8 in my technical document.

The hero and enemies of Elevator Fight is displayed by this function.

 

The division function is, to divite the sprite to left and right or top and bottom,

and select whitch side is dispayed.

In this case, the sprite size is changed to 8x16 or 16x8.

Please refer page 9 in my technical document.

In Nekketus Kung-Fu Load, both left-side and right-side face patterns are in one sprite.

In Lupin 3rd, the flapping patterns of the bat are also in one sprite dividing top and bottom.

(NOTE: this function is disabled for these pictures to describe the specification of function,

and my emulator can display these scenes correctly.)

 

 

Sound Generator)

 

It seems that uPD1771C is the sound generator.

I could not find the datasheet, but I heared it is the old signal processor.

It supports at least 3 types of sound, tone, noise and 1bit PCM,

but only one sound can be generated.

So for example Sky Kid, when we shoot and the sound effect BOMB are played,

the back ground music is stopped.

 

Tone)

There are at least 8 patterns of wave.

We can specify the wave pattern, frequency, detune and volume parameters.

 

Noise)

At least 2 types of noise are supported.

They are the whilte noise and the sawtooth wave-like noise.

 

1bit PCM)

Yes, to our surprise, this console supports 1bit PCM!

The sound rate is about 9KHz.

It seems that uPD1771C does not have enough PCM buffer,

so CPU must send the PCM data continuously while PCM is playing.

 

 

Thanks,

TAKEDA, toshiya

-----

http://www1.interq.or.jp/~t-takeda/

Edited October 25, 2008 by TAKEDA, toshiya

[Crazyace]

That's a nice document - and your site is really cool - it's interesting seeing the older japanese machines

[Crazyace]

How do Miner2049er and Boulderdash compare with the 8 bit originals?

[TAKEDA, toshiya]

How do Miner2049er and Boulderdash compare with the 8 bit originals?

 

I created some movies.

(They are compressed in x264 mp4 format.)

 

http://www1.interq.or.jp/~t-takeda/scv/boulder_dash.mp4

http://www1.interq.or.jp/~t-takeda/scv/miner2049er.mp4

http://www1.interq.or.jp/~t-takeda/scv/start_speeder.mp4

http://www1.interq.or.jp/~t-takeda/scv/wai...moster_land.mp4

http://www1.interq.or.jp/~t-takeda/scv/kung_fu_road.mp4

http://www1.interq.or.jp/~t-takeda/scv/nebula.mp4

 

I hope they help you to compare EPOCH Super Cassette Vision and Atari 7800 or other consoles.

 

Thanks,

TAKEDA, toshiya

-----

http://www1.interq.or.jp/~t-takeda/

[Artlover]

We need an Epoch emulator for Xbox.

[Crazyace]

Boulderdash is interesting - a 10x12 array of sprites for the background. It looks like the sprites are offset a few pixels from the backdrop - so the lores 8x8 BG mode can be used to give a 2nd colour for the diamonds. ( and the bowties as well - but they dont appear in the video )

I dont think it's as powerfull as the 7800 ( apart from the usual sound ) the basic res is slightly higher ( I'd guess 256 clocks per line, given 192 in the same way the 2600/7800 have 160/68 ) but the sprites are single colour only.

 

Takeda-san, Do any of the games flicker, - if 2 colour sprites are in a line? Are there any homebrew games for the SCV?

[keitaro]

Hi,

I discovered this system with your web page. I liked the look of the games.

I downloaded the emulator, but I didn't find rom images anywhere, so I forgot it, until now.

I see the videos, can you upload videos from Astro Wars and Battle in Galaxy, please?

Thanks!

[Kurt_Woloch]

Hmmm... now that's a very unique architecture. With that text / BG mode, are you saying that ALL the high resolution graphics in games are created with sprites, since the background can only do relatively big color blocks?

Well, it doesn't seem to matter since if really 30 sprites are supported per line, it's possible to fill the whole screen with sprites for a background.

In that respect the system is similar to the Atari 7800, which doesn't really divide background and sprites... there the whole screen (or, rather, each scanline) is composed of different size layers which get displayed over each other.

It also reminds a bit of the G7000 / Odyssey^2 in that for certain things, only the built-in characters are supported (in this case, the text mode), and in that almost all of the more complex graphics is done with sprites. However, the SCV clearly surpasses the G7000. I'd put it roughly on par with the Colecovision, though it's probably more tricky to program with all the trickery you have to do in order to put a meaningful background on screen.

And of course, the sound is probably even worse than on the Atari 2600 and 7800, having only 1 sound generator. But it seems that that one generator at least is able to put out better sounding melodies than the Atari 2600 (not so far off-key).

 

Do you happen to have screenshots or even a video of Pole Position (or was it Pole Position II)? I'd really like to see how that one turned out...

[Crazyace]

I guess it makes more sense to have more sprites for a game/arcade console - after all the TI chip was designed for a home computer - not just a games machine.

The text seemed strange - skipping odd lines

In the emulator the font is 128 chars only , with the bottom 8 lines of the 8x16 blank - I wonder what happens on the real machine if bit 7 of a char is set? It would be cool if it changed the char from top to bottom 8 lines

[darthkur]

Dear members,

 

My name is TAKEDA, toshiya.

I am the developer of Super Cassette Vision emulator.

http://www1.interq.or.jp/~t-takeda/scv/index.html

 

Well, I downloaded the binaries and the emulator seems to work but there's no game roms to be found anywhere for it. Do you happen to host those as well or know where they can be found?

[TAKEDA, toshiya]

Hmmm... now that's a very unique architecture. With that text / BG mode, are you saying that ALL the high resolution graphics in games are created with sprites, since the background can only do relatively big color blocks?

 

Please refer this picture about text and sprite screen:

http://www1.interq.or.jp/~t-takeda/scv/scv_screen.png

 

Now the real machine is in the storehouse. so I cannot check the flicker.

But I think there were no flickers in Boulderdash case.

 

Sorry I have not dumped Pole Position ][ yet.

(Every carts except PP2 ware already dumped.)

I will upload the movie of AstroWars and Battle In Galaxy in this week.

 

Thanks,

TAKEDA, toshiya

-----

http://www1.interq.or.jp/~t-takeda/

[Kurt_Woloch]

Please refer this picture about text and sprite screen:

http://www1.interq.or.jp/~t-takeda/scv/scv_screen.png

 

I see... there seems to be some kind of trickery involved here. What actually surprises me here is that it also seems to be possible to have a text window on the left, and coloured background on the right.

Actually, how the text looks like reminds me a bit of the VIC-20 home computer.

 

Sorry I have not dumped Pole Position ][ yet.

 

Never mind... I found a screenshot meanwhile, it's printed on the cover of the game, here:

 

http://www.old-computers.com/MUSEUM/softwa...p;c=&id=288

 

But I'd really like to read the technical description you wrote in that PDF. Unfortunately, I can't read any Japanese. Is there an English version of it, maybe (other than the main points you gave here)?