Crazyace

The tech is based on when it's launched first, not where... so I'd compare winter 93 against winter 94 You'd be surprised at how long the PS tech was in development

But those threads are boring.... someone says 'If Atari had all the must have games, mass advertising etc etc they would have been a success' and everyone else agrees.

The 5200 and the CV had different strenghs - the CV was higher res with more sprites, but lacks the scrolling and multicolour modes of the 5200. It's interesting that the CV graphics chip comes from the TI99 computer ( released in 1979 for ~$1100 ) and the 5200 comes from the 400 ( released in 1979 for $550 ) The funny thing is by 1982 the Atari 400 was around $200

Here's a new version with proper movement, rather than a hacked fixed screen. It's not double buffered yet, so you can see the beam catch up with the sprite drawing... Also, only the horizontal kernel is there at the moment ( I'll work on the vertical kernel tomorrow ) The nice thing about this method is all 5 objects can be on the same line without any flickering, and each sprite is 4 colours, so the ghosts have eyes. The code is not optimised fully yet either code.zip

Also, I wrote some code that shows an arcade effect ( 2 layer real parrallax scrolling ) that isn't possible on the CV, but seems quite easy on the 7800. It even works in the higher resolution mode. If you accept the 160 pixel res limitation I think the 7800 version of Donkey Kong is better than the coleco version - the barrels are multi coloured.

According to it's copyright screen TankWars is 1983. I always found the 5200 a bit wierd - it's a slightly better Atari 400 - why not just put a membrane keyboard on it? The 7800 is really cheap in some ways, the CV and the 5200 both had at least 16k ram, and nice® sound chips - the 7800 had 4k

It's not really a hack, more a graphics demo - it's based on a screen grab of mame pacman, so I've not rescaled anything at the moment

The Colecovision and MSX are pretty much identical in certain ways , so the blocky scrolling in Sky Jaguar isn't a problem with the port - it's a limitation of the chip. I dont know the limitations that well - I think better vertical scrolling could be implemented on the CV, but it wouldn't be easy. The 5200 was a bit strange - it was old tech already when launched , and it's sprites were quite weak - it would have been so cool if the antic/gtia had been redesigned I wonder if it would have been more successfull if it had just been a 'console' version of the atari400 with the same cartridges. I think the danger with changing graphics in MattPatrol is that you run out of characters, as you need 8 copies of the city to produce the illusion of smooth scrolling. Even if the graphics were improved it wouldn't be possible to have the city scroll in front of the mountains

How about.. rem * New bad guy direction x (left/right) newbaddx temp5=rand : if temp5<128 then goto leftrightcheck temp5=badplayfx+2 : if !pfread(temp5,badplayfy) then goto badguygoright leftrightcheck temp5=badplayfx-1 : if !pfread(temp5,badplayfy) then goto badguygoleft temp5=badplayfx+2 : if !pfread(temp5,badplayfy) then goto badguygoright goto movebaddone

I had an extra line, but it screws up Atari800Win - not sure if that's the same on the real machine. I left it in to see if it would be visible on a real machine.

It's been a long time since I looked at the SNES - but I think mode 3 with 256colour main screen and 16 colour sub screen blended on would give 256*16 basic - more with extra pallettes switching per line maybe.. Not as good as the YJK mode though - that's pretty cool

Although it's pretty impressive, it's mainly character graphics - and the scrolling hurts the eyes. It would have been cool to see it on CV though - has anyone tried porting it?

Notice the differences in Q-Bert himself, the ball, and the cube orientation. Not fair. You cannot compare modern homebrews with legacy commercial games. Today's programmers have more cartridge memory, almost unlimited time, more resources, etc. Did the 7800 get a version of Frogger or Q*Bert back in the 80s? No, so you cannot compare those games. Of course much better versions of Frogger and Q*Bert would be produced on the CV today. About the 100 objects on screen thing, I believe (and I can be wrong here) that part of that is used for background graphics too, right? So you don't have 100 objects to move around, unless we are talking about games with no background at all, like Galaga (ok, even Galaga has a starfield). Another thing is how difficult it’s to program for each console. I can tell you just from reading the 7800 docs, that the 7800 is far more difficult to program because of the "funny" (to not say outdated, even for the 80s standards) video scheme it uses. Then Maria steals cycles from the 6502, as does any access to the controllers and sound chip. And I would say that even the display list steals cycles, because the program need to keep the list ordered all the time (extra processing that the TMS9918 sprite system doesn't require). Finally the CV has better horizontal resolution (256 pixels versus 160 pixels on the 7800). Then the 7800 has just 2 audio channels, while the CV has 3 (or 4, if you count the noise channel). Finally the CV uses a Z80, which was used by more than 80% of all arcade games during the 1979-1984 period. Aside Atari, how many companies consistently used the 6502 for arcade games? Don't you think that means something? So generally speaking I could say that the 7800 can produce slightly better graphics, it has hardware scroll, more colors, but lower resolution. However it isn't as good as the CV in the sound department and the CV could offer more processing power for game logic since it uses a Z80 and there is nothing stealing cycles from it. Part of the fun in old systems is trying to get more out of them... I think it's not the 100's of sprites, more the lack of flicker - but the coleco does have an edge having 256 only vs 160/(320 cut down) and the standard sound is no comparision. Some things are hard on the 7800, but there are also some hard things to do on the CV. 6502 v Z80 - to me they're pretty much the same.

The V9938 can only do vertical fine scroll. However the V9958 can do both vertical and horizontal. The V9958 also offers 19K colors on screen at the same time. That was in the MSX2+ wasn't it .... How popular was it ( I'd guess it's a bit like the STe - where the extra features were just too late ) 19k, Couldn't you get that amount of colours on a SNES at that time?

Hi, I was thinking about some things in one of the 7800 topics ( when CVGus bought up the colecovision Pacman compared to the atari pacman ) and it led to this quick hack.. I'd be interested in what this looks like on a real Atari, as the emulator shows a yellow line at the bottom ( and if I increase the display it barfs ) It's for an 8 bit , but a 5200 version should be trivial to prepare. code.zip

No, the line buffers aren't available on Maria. - Can OPL make a stable display, I thought the height/address fields had to be reprogrammed every frame?

Do you have a .bin version of this for us Cuttle Cart owners? I've put one in the zip here, though you should be able to build it from the source if you want to change anything. code.zip

They are both using hardware scrolling - just 2 different resolutions. The only thing is that the 7800 scrolling scrolls 2 pixels at a time in 320 mode, so I'd have to have two sets of graphics for the mountains to get a 320pixel res scroll. The graphics are the arcade graphics, and they scroll as two layers, rather than two 'stripes' on the CV version ( Which is still quite impressive for a machine with no scrolling H/W and character set graphics ) It's a lot more work using the 320 mode for the 7800 - so in practise it would be better to use the 160 mode, which would allow a lot more in terms of sprites per line. It would be possible to have multi coloured hills, but very limiting - for a still image you need 2 colours per 8 pixels - if it scrolls you need 2 colours per 16 pixels at least.. ..aa..aa ..bb..bb is ok for still but if you scroll 1/2 char you get ......aa ..aa..bb ..bb.... which breaks the colour tile Actually I think you wont be able to mix colours - but you could scroll this ..aa..aa ........ ..bb..bb after 1/2 char it's ......aa ..aa.... ......bb ..bb.... which is ok The big problem with having more graphics is the character count - for the CV matt patrol there are 8 copies of the graphics to support the pixel scroll, and this limits the size, so as you see the mountain and city are very repetitive. The hill is quite clever, as the gradient is repeated, so some characters are reused.

I should do something with it - it was only an exercise to show the moon patrol background scrolling to compare with the coleco matt patrol for CV gus ( Looking at it I think I could duplicate the 160 version on a 5200 as well )

Arcade Moon Patrol used a standard 4:3 (aka 1.333:1) aspect ratio. To produce a subjectively arcade-perfect port the graphics would need to be redrawn, since at the original width they're too narrow, and at doubled width they're too wide. http://www.subarubrat.com/PICS/defmoon.jpg Your absolutely correct - for some reason I thought it was a portrait monitor like space invaders... ( I grabbed the original mountains and hills to test, but cutting from several screenshots of the arcade game being played )

I hated Galaxians and Pacman on the 8 bit... they didn't seem to be the 'real' games. ( unlike Donkey Kong, which was far closer ) - I looked at the coleco version and it's a lot closer, but still suffers from the single colour sprites.

Hi, The two screenshots show the 160 mode and the 320 mode. The scrolling is 160pixel res as the HW scrolling on the 7800 is fixed to that res ( same as the 5200 )

Here's another a78 to show moon patrol in two modes.. Use left/right to scroll, and up/down to switch between 160 and 320 pixel mode. ( The 320 mode is a 240 wide screen centred - matches the arcade vertical aspect ratio more ) It's still a hack - but it shows something you couldn't do on the colecovision - or even on a NES or SMS. ( Maybe on the SMS - with heroic charset manipulation.... ) I've not run this on a real 7800 yet, just through the emulator - so if anyone tries it, let me know if there are any issues.. code.zip

I hadn't thought of that ( Thanks to Albert as well for the response ) Here's the code and a78... code.zip

This shows how a moon patrol might work on the 7800... Although the res is 160 ( rather than 240 ) the 7800 can handle the 2 independant overlapping scrolls, which is something the CV would find extremely difficult ( The Moon Patrol on the CV does do a very good job of scrolling using the charset ) (actually you need to wait.. I cant attach the a78 for some reason )