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Atari Microsoft BASIC
The Atari Microsoft BASIC and Atari Microsoft BASIC II variants of the 6502-version of Microsoft BASIC ported to the Atari 8-bit computers. The first version, released 1981, required 32 KB of RAM and was supplied on floppy disk. The second version, released the next year, had most of the code on a ROM cartridge with additional functions on an optional floppy.
Atari Microsoft BASIC was highly compatible with contemporary Microsoft BASIC releases such as Applesoft BASIC and Commodore BASIC, in contrast to Atari BASIC which was a somewhat different dialect developed by Shepardson Microsystems and incompatible in several ways. Like Atari BASIC, Atari Microsoft BASIC included a number of new commands and features to take advantage of the Atari platform. These were only partially compatible with the similar features of Atari BASIC.
When Microsoft ported their originally Intel 8080-based BASIC to the 6502, they took the time to expand the floating-point format from the original 32-bit format to an optional 40-bit format for improved accuracy. Both versions could be compiled from the same code by providing compiler flags; if the 32-bit format used the resulting code was just under 8 KB in length, if the 40-bit format was used, it was closer to 9 KB.
The Atari 8-bit home computers were designed with a slot for an 8 KB or, optionally, 16 KB ROM cartridge. Atari's programmers struggled to fit Microsoft's BASIC into an 8 KB cartridge while also adding features to take advantage of the platform. In the summer of 1978, Atari decided to outsource the porting effort so that BASIC would be ready in time for the 1979 launch of the system, and this led them to Shepardson Microsystems Inc. (SMI). SMI quickly decided the job was impossible and instead proposed creating an entirely new version of BASIC. This became Atari BASIC and was released with the Atari 400 and 800 in 1979.
Atari continued working with the MS code and released a version of it on floppy disk in 1981. In addition to the extended range of standard commands in MS compared to Atari BASIC, the new version added a number of additional commands for graphics and sound and other features of the platform. It also included integer variables and a complete integer math package which offered improved performance. However, as it required at least 32 KB of RAM and only ran from a disk, it was never particularly popular.
A second release, Atari Microsoft BASIC II, moved most of the code onto an expanded 16 KB cartridge and placed an additional 11 KB of more rarely used code on disk, meaning that many programs intended for cross-platform use could now be run from the cartridge alone. Released in 1982, BASIC II also saw little real-world use.
The underlying interpreter was based on the same 9 KB MOS 6502 code that also formed the basis of Commodore BASIC and AppleSoft BASIC, and was largely compatible with them. A key aspect of this was the string handling system, which was based on the same code as those platforms. In contrast, Atari BASIC used an entirely different system that treated strings as arrays of characters and was not compatible with, nor easily ported from, most other systems.
It retained the original 40-bit format floating-point arithmetic library that replaced the notoriously slow one in the system's operating system ROMs, and thus ran math code at the same speed as other platforms, and much faster than Atari BASIC. It also included an additional integer math package for added performance. The integer math system was triggered when the assignment was to an integer variable, or the literal values were all integers. If either was not true, the integer values would be converted to floating-point, use the floating-point code for the calculation, and then be converted back to integer for storage.
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Atari Microsoft BASIC AI simulator
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Atari Microsoft BASIC
The Atari Microsoft BASIC and Atari Microsoft BASIC II variants of the 6502-version of Microsoft BASIC ported to the Atari 8-bit computers. The first version, released 1981, required 32 KB of RAM and was supplied on floppy disk. The second version, released the next year, had most of the code on a ROM cartridge with additional functions on an optional floppy.
Atari Microsoft BASIC was highly compatible with contemporary Microsoft BASIC releases such as Applesoft BASIC and Commodore BASIC, in contrast to Atari BASIC which was a somewhat different dialect developed by Shepardson Microsystems and incompatible in several ways. Like Atari BASIC, Atari Microsoft BASIC included a number of new commands and features to take advantage of the Atari platform. These were only partially compatible with the similar features of Atari BASIC.
When Microsoft ported their originally Intel 8080-based BASIC to the 6502, they took the time to expand the floating-point format from the original 32-bit format to an optional 40-bit format for improved accuracy. Both versions could be compiled from the same code by providing compiler flags; if the 32-bit format used the resulting code was just under 8 KB in length, if the 40-bit format was used, it was closer to 9 KB.
The Atari 8-bit home computers were designed with a slot for an 8 KB or, optionally, 16 KB ROM cartridge. Atari's programmers struggled to fit Microsoft's BASIC into an 8 KB cartridge while also adding features to take advantage of the platform. In the summer of 1978, Atari decided to outsource the porting effort so that BASIC would be ready in time for the 1979 launch of the system, and this led them to Shepardson Microsystems Inc. (SMI). SMI quickly decided the job was impossible and instead proposed creating an entirely new version of BASIC. This became Atari BASIC and was released with the Atari 400 and 800 in 1979.
Atari continued working with the MS code and released a version of it on floppy disk in 1981. In addition to the extended range of standard commands in MS compared to Atari BASIC, the new version added a number of additional commands for graphics and sound and other features of the platform. It also included integer variables and a complete integer math package which offered improved performance. However, as it required at least 32 KB of RAM and only ran from a disk, it was never particularly popular.
A second release, Atari Microsoft BASIC II, moved most of the code onto an expanded 16 KB cartridge and placed an additional 11 KB of more rarely used code on disk, meaning that many programs intended for cross-platform use could now be run from the cartridge alone. Released in 1982, BASIC II also saw little real-world use.
The underlying interpreter was based on the same 9 KB MOS 6502 code that also formed the basis of Commodore BASIC and AppleSoft BASIC, and was largely compatible with them. A key aspect of this was the string handling system, which was based on the same code as those platforms. In contrast, Atari BASIC used an entirely different system that treated strings as arrays of characters and was not compatible with, nor easily ported from, most other systems.
It retained the original 40-bit format floating-point arithmetic library that replaced the notoriously slow one in the system's operating system ROMs, and thus ran math code at the same speed as other platforms, and much faster than Atari BASIC. It also included an additional integer math package for added performance. The integer math system was triggered when the assignment was to an integer variable, or the literal values were all integers. If either was not true, the integer values would be converted to floating-point, use the floating-point code for the calculation, and then be converted back to integer for storage.