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hardware [2016/05/22 20:05] ex_writer [Hardware] |
hardware [2016/06/05 15:33] (current) ex_writer |
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| The Bally Professional Arcade is a full-color videogame system based on the mass-RAM-buffer technique. A mass-RAM-buffer system is one in which one or more bits of RAM are used to define the color and intensity of a pixel on the screen. The picture on the screen is defined by the contents of RAM and can easily be changed by modifying RAM. | The Bally Professional Arcade is a full-color videogame system based on the mass-RAM-buffer technique. A mass-RAM-buffer system is one in which one or more bits of RAM are used to define the color and intensity of a pixel on the screen. The picture on the screen is defined by the contents of RAM and can easily be changed by modifying RAM. | ||
| - | The system uses a Z80 microprocessor as its main control unit. The system ROM has software for four games: Gunfight, Checkmate, Scribbling, and Calculator. Additional ROM can be accessed through the cartridge connector. Three [[custom chips]] control the video interface, special video processing functions, keyboard and control handle interface, and audio generation. | + | The system uses a Z80 microprocessor as its main control unit. The [[software:system ROM]] has software for four games: Gunfight, Checkmate, Scribbling, and Calculator. Additional ROM can be accessed through the cartridge connector. Three [[hardware:custom chips]] control the video interface, special video processing functions, keyboard and control handle interface, and audio generation. |
| - | The system exists in both high-resolution and low-resolution models. The three [[custom chips]] can operate in either mode. The mode of operation is determined by bit 0 of [[output port]] 8H. It must be set to 0 for low-resolution and 1 for high-resolution. This bit is not set to 0 at power up and must be set by software before any RAM operations can be performed. | + | The system exists in both high-resolution and low-resolution models. The three custom chips can operate in either mode. The mode of operation is determined by bit 0 of [[hardware:i o ports|output port]] 8H. It must be set to 0 for low-resolution and 1 for high-resolution. This bit is not set to 0 at power up and must be set by software before any RAM operations can be performed. |
| - | **NOTE:** The Astrocade only has access to low-resolution output. High-resolution output was available in certain Bally arcade titles. Further references to the high-resolution mode are omitted. For further information about this mode, please consult the original Nutting Manual. | + | **NOTE:** The Bally Arcade only has access to low-resolution output. High-resolution output was available in certain Bally arcade titles. Further references to the high-resolution mode are omitted throughout the Better Bally Book. For further information about this mode, please consult the original Nutting Manual. |
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| Hardware is divided into the following subsections: | Hardware is divided into the following subsections: | ||
| - | * [[Memory Map]] | + | * [[hardware:Memory Map]] |
| - | * [[Screen Map]] | + | * [[hardware:Screen Map]] |
| - | * [[Color Mapping]] | + | * [[hardware:Color]] |
| - | * [[Vertical Blank]] | + | * [[hardware:Interrupts]] |
| - | * [[Interrupt Feedback]] | + | * [[hardware:Magic System]] |
| - | * [[Magic Register]] | + | * [[hardware:Player Input]] |
| - | * [[Player Input]] | + | * [[hardware:Music Processor]] |
| - | * [[Music Processor]] | + | * [[hardware:i o ports|Input/Output Ports]] |
| - | * [[Output Port|Output Ports]] | + | * [[hardware:custom chips|Custom Chips]] |
| - | * [[Input Port|Input Ports]] | + | * [[hardware:expansion|Expansion]] |
| - | * [[Custom Chips]] | + | |
| - | ===== Memory Map ===== | + | ---- |
| - | + | ||
| - | In both the low- and high-resolution models, the operating system ROM is in the first 8K of memory space. Cartridge ROM resides in memory between 8K to 16K. Standard screen RAM begins at 16K and occupies 4K bytes. Magic screen RAM begins at location 0. It is the same size as standard screen RAM. Memory space 20K–32K is available for expansion. | + | |
| - | + | ||
| - | When data is read from a memory location between 0–16K, the data come from ROM. When data is written in a memory location (X) between 0–16K, the system actually writes a modified form of the data in location X+16K. The modification is performed by the [[Magic Memory|magic system]] in the Data Chip and Address Chip. Thus the RAM from 0 to 16K is called [[Magic Memory]]. | + | |
| - | + | ||
| - | {{low_memory_map.png}} | + | |
| - | [NM:82–3] | + | Image source: [[http://www.ballyalley.com|Bally Alley]] |
