Simulating Different Graphics Modes

[peteym5]

As I been porting over different games and reading posts, I see people are looking for stuff that require graphics modes not normally found on the 7800. Some games need bit mapped modes like Tempest, Surround, Slither, Qix, etc. Need to do functions like Plot pixles, drawing lines, or fill regions. What I had started up is a few fonts that can help emulate the modes like we see on the 8-bit. Graphics Modes 4 and 5 that are 80x48 pixel can be simulated with a character font with 2x2 blocks per character, 2 or 4 possible colors. The 7800 has 4K RAM, and some of it being used for zero page, stack, display lists, game variables, etc. These fit in just over 1K RAM + 1K ROM for the font.

 

I am also including some fonts that can be used draw lines at various angles. Useful for like laser beams, or maybe the web in Tempest.

 

I know some solutions may required the RAM on cartridge or RAM in the XM modular. But from experience, I learned it is best to design your game to work on a stock system. Also, cartridges with more than an EPROM + Control chip may start costing more. I know that I do need to research cartridge types on the 7800.

Fonts emulate Graphics Modes.zip

Edited December 3, 2017 by peteym5

[Trebor]

As I been porting over different games and reading posts, I see people are looking for stuff that require graphics modes not normally found on the 7800. Some games need bit mapped modes like Tempest, Surround, Slither, Qix, etc. Need to do functions like Plot pixles, drawing lines, or fill regions. What I had started up is a few fonts that can help emulate the modes like we see on the 8-bit. Graphics Modes 4 and 5 that are 80x48 pixel can be simulated with a character font with 2x2 blocks per character, 2 or 4 possible colors. The 7800 has 4K RAM, and some of it being used for zero page, stack, display lists, game variables, etc. These fit in just over 1K RAM + 1K ROM for the font.

 

I am also including some fonts that can be used draw lines at various angles. Useful for like laser beams, or maybe the web in Tempest.

 

I know some solutions may required the RAM on cartridge or RAM in the XM modular. But from experience, I learned it is best to design your game to work on a stock system. Also, cartridges with more than an EPROM + Control chip may start costing more. I know that I do need to research cartridge types on the 7800.

 

Thank you for sharing the fonts.

 

This site will likely be found as very beneficial. It includes information on all original retail cartridge types, including the ones utilized for Impossible Mission, Tower Toppler, and Jinks which contained 8K RAM, as well as Winter Games and Summer Games, each containing 16K RAM.

 

Additionally, both the Plutos and Sirius prototype games utilize 16K RAM, but some cartridges contain 32K SRAM as it was easier to procure. CPUWIZ's PCBs have been fulfilling the needs of these games.

 

There is also a bankswitched 256K ROM with dual bankswitched (16x2) 32K RAM configuration, highlighted several years back.

 

P.S. A company that often added to the capabilities of their "stock" console has one of the most renowned systems of all-time with an ~800 games library. Absolutely, there is benefit in developing a game to work on a stock system, whether it is "best" would be a hard argument to make in light of the aforementioned.

[peteym5]

I looked over that list. Those should be the same cartridge types Video61 and Albert have in stock. As far as I know cartridges with POKEY have no bank switching or RAM onboard.

 

I know bank switching cartridges are available to handle up to 512K. Seems anything over 64K is ROM only, either lack the POKEY or RAM. I know there are some boards people made more recently that may be bank switching + RAM + Pokey. It would be great to get a hold of a few for Tempest. I am not sure how Flash cartridges are done, if they include Pokey and/RAM.

[Trebor]

I looked over that list. Those should be the same cartridge types Video61 and Albert have in stock. As far as I know cartridges with POKEY have no bank switching or RAM onboard.

 

I know bank switching cartridges are available to handle up to 512K. Seems anything over 64K is ROM only, either lack the POKEY or RAM. I know there are some boards people made more recently that may be bank switching + RAM + Pokey. It would be great to get a hold of a few for Tempest. I am not sure how Flash cartridges are done, if they include Pokey and/RAM.

 

For certain Albert has many, if not all, of CPUWIZ's PCB boards as those are what is utilized on AtariAge. While original retail Ballblazer is 32K, contains a POKEY chip, and indeed does not perform any bankswitching, Commando, containing a POKEY and is 128K, performs bankswitching.

 

The limit without bankswitching is 48K. That means other POKEY games, such as homebrew release Super Circus Atari Age @32K, contains no bankswitching; ditto for the POKEY version of Beef Drop. However, Bentley Bear's Crystal Quest and Donkey Kong PK, both 144K games and have a POKEY chip, contain bankswitching.

 

From the original retail library of games containing RAM, Tower Toppler is the only title that is 64K. Impossible Mission, Jinks, Summer Games and Winter Games are 128K.

 

Frankie Goes To Hollywood's Relax is a 1MB bankswitching cartridge. The #2 Anniversary Multi-Cart is also a 1MB bankswitching cartridge, containing eight 128K games.