Crazyace

I think both the 7800 and the 5200 had a lot more potential, especially the 7800... As the 5200 was basically an 8 bit .. in theory anything could be done ( with a big enough cartridge ) - look at Yoomp and the other 130Xe ( and higher ) code.. The one big advantage the coleco has is that it's designed for 256 pixels.. the 7800 can support 320, but it needs more work - and things are really intended for 160 pixel. oh - the CPU is better on the CV, not because of any 6502 vs Z80 issue, but purely due to the fact that Maria steals 6502 processor cycles..

I dont think there's any 'overlapping' zones, so I think it's just redefined characters - the city scroll only seems to use 1 colour per line, so there's no attribute problems. ( Actually, if you run it with Meka you can see the tile map, with the multiple definitions of each char )

The palettes has 32 entires of 2bit RGB (64 colors), unlike some other systems that use HSV. So there would be no way to display more colors than what the palette has. Not like the NES which has 52 colors but additional color emphasis bits allowing for up to 400+ color palette ( though only accessible in fixed segments of 52 colors). How does that work on the NES? I've never heard much about it before.. ( Not that I've looked at the NES much, went from Gameboy/Gamegear to SNES in programming ) Found it now... just had to read some docs...

How much cpu time would it take to fine scroll vertically on the CV? I've no idea what the limit for data movement per frame is ( it was a bit of a killer having a limit on gameboy/gamegear - even on snes/megadrive )

Makes sense - minimises the numer of sprites on a line - leaving the missiles ,bullets and aliens to be sprites. I didn't see any point where the two hills intersect though, Is that later in the game?

Looking at a lot of the cheap DVD players, dont they have enough grunt to run everything an Atari 8 bit ( or even an ST ) could run. You get models like this in the states http://www.amazon.com/Coby-DVD-209-Ultra-C.../ref=pd_sim_e_1 which are pretty cheap... I bought a DVD for about $20 in Shanghai, that had a USB port - you could supply games on DVD ( cheap ) and use a USB stick for storage... ( with a USB kb for programming ) The only thing it lacks as a 'PC' is the net

The game gear was a lot better - not just because of the pallette, but also because there was a lot more time to transfer data across ( due to the number of display lines being reduced )

Not really, they're both 8 bit machines, with video chips containing seperate vram Both character based machines with sprites Both MSX and Coleco use z80 and a form of TI VDP chip ( as does the Sega system ) I consider them different to the Atari/C64/7800 style where the video ram is just part of the normal cpu memory system.

Theoretically yes, but you also have a horizontal screen position register, which is used in Space Manbow for scrolling. That's why at the borders, you see characters disapperaring, because it moves the whole screen up to 8 pixels to the left, and then repositions it. Ok, that's how I to fine scroll using the 6845 - I guess you get a bonus with the 9938 that you can hide the sides using sprites No offense, but I think the MSX2 is much better equipped for scrolling games than the ST (except the weak 3,58Mhz Z80 CPU). The 9938 even can blit memory regions around in VRAM, plus it has 32 hardware sprites. The ST practically has only the 68000 to do all the dirty work. No argument there , I'd have killed for a proper 'nibble' screen format, and ability to set the low byte of the display address.. The MSX2 did come out after the ST though - and given the smaller memory and use of the z80 I never looked at it much ( even though the graphics modes seemed better )

I was well into the ST by the time the MSX2 appeared - I had a quick look on wikipedia - and it mentioned that the MSX2 only had vertical fine scroll? ( Not that the ST was much better - to get horizontal scrolling I had 8 copies of my screen, which did waste quite a bit of memory )

It's a pity that there was no timing exposed ( a la 6845 ) Did anyone ever try hacks to fool scrolling ( like the no border code for C64 and ST )? I guess anything like that wouldn't have been approved at the time by Coleco though.

A 7800 with the effort put in to match the 2600 software would have been great.. The lack of fine scrolling on the Coleco and MSX videos hurts my eyes The still screenshots look great, but the movement is so jerky

For me it's interesting that the Atari competition for the Colecovision was the 5200, not the 7800. ( especially given the Colecovision uses the graphics chip from the TI99/4A, which competed with the Atari/Apple/C64 ) The 7800 sound did suck - ( apart from Ballblazer ) I think apart from that it's just the choice of the 160 vs 256 resolution.

Sure but can you give more explanation on how that benefit can be used in practice? the Colecovision has substantially more memory than the 7800 or NES. I should have said 7800 - got jaguar on the brain here.. I prefer the 7800 style, I think it's way more advanced than the coleco - the only big advance is the res. I looked at some of the games on the coleco - the scrolling is pretty poor in most of them. I've not been interested in programming it much though, but I found the 4k ram on the 7800 pretty limiting

I think the NES is more an evolution of the colecovision ( or the SegaMaster system is a direct evolution ) An evolution of the 7800 is the jaguar. One way the stock coleco is way better than the jaguar is the ram - 16k vram ( +1k work ram ) vs. 4k

and no flickering is a big help for the 7800

The trouble with crap games, is that they are often crap regardless of the system power Hoverstrike is a good quality Jaguar game, but it didn't seem 'mass market' enough The Jag should have had Street Fighter and SNK games, and more games like Rayman

I really wanted some cool 2d games for Jaguar - I'd been playing the Sega Arcade games ( Outrun, PowerDrift etc ) and the Jaguar seemed perfect to give 'better than Arcade' versions of those. Cybermorph was nice, but seemed like a 'Amiga/PC/ST' game that ran more smoothly..

What about Bandits - I loved that game, and I think it moved around a ton of sprites as well.. The BBC model B had a good version of Galaga - using a bit map screen twice as large as the A8, so I dont think it would have been impossible

My name in lights

66MHz is a bit faster than the cobweb though - I guess this is your target speed for the new chip? I've found that a big problem with emulation sometimes isn't emulating too fast, but actually emulating at the exact same speed... I thought the only RISC chip with cache was on puck - The Oberon one seemed very similar to Tom. I suppose if you look at how the cache was implemented on Nuon that would probally be indicative of what they intended for puck

Interesting idea - it would be quite difficult to run at the same speed though..

I'm not sure that was true - the 68k was in the cobweb board - and in the docs it doesnt talk about a 68020 - ( or in any interviews ), the idea seemed to be that the 68k was only there for Jag compat and boot - and Jag II games would ditch it once the RISC had started ( something to warm Gorf's heart ) ( To me - putting a 68020 in JagII wouldn't make any sense at all - at worst it would screw up the timing of old games - ruining backwards comp... )

Just another indication of how rushed things were - the extra RISC processor was in Puck - so the first games developed on Cobwebs would have been very similar to Jag 1 games ( in the use of the 68k ) - just with better texturing.

It does seem a pity that the puck netlist isn't floating around - I wonder if this, and the fact that cobweb had a jerry chip, may have implied that puck hadn't actually completed design