This page (revision-114) was last changed on 24-Feb-2023 14:10 by Andreas Tartz 

This page was created on 08-Mar-2010 20:15 by Carsten Strotmann

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Version Date Modified Size Author Changes ... Change note
114 24-Feb-2023 14:10 18 KB Andreas Tartz to previous
113 24-Feb-2023 13:11 18 KB Andreas Tartz to previous | to last
112 24-Feb-2023 13:09 18 KB Andreas Tartz to previous | to last
111 24-Feb-2023 13:06 17 KB Andreas Tartz to previous | to last
110 24-Feb-2023 12:57 17 KB Andreas Tartz to previous | to last
109 24-Feb-2023 12:53 17 KB Andreas Tartz to previous | to last
108 24-Feb-2023 12:38 17 KB Andreas Tartz to previous | to last
107 03-Feb-2023 15:21 17 KB Maury Markowitz to previous | to last
106 13-Dec-2021 16:05 17 KB Maury Markowitz to previous | to last
105 16-Sep-2021 13:46 17 KB Maury Markowitz to previous | to last
104 16-Sep-2021 13:30 17 KB Maury Markowitz to previous | to last general cleanup
103 29-Jul-2020 21:57 17 KB Peter Dell to previous | to last TURBO-BASIC XL ==> Turbo-BASIC XL
102 23-May-2020 05:03 17 KB Roland B. Wassenberg to previous | to last
101 01-May-2020 02:03 17 KB Roland B. Wassenberg to previous | to last

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Atari BASIC
Atari BASIC

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At line 6 changed one line
Atari originally licensed the 6502-assembler code for Microsoft BASIC. This came in two versions, one that was about 7900 bytes that used a 32-bit (6-digit) floating point number format, and another that was closer to 9000 that included an expanded floating point format with a 40-bit (9-digit) numbers. The vast majority of 8-bit machines used the larger 9k/40-bit version, and then further expanded it with additional functions for basic input/output. For instance, the BASIC, character set and I/O in the early PET machines was supplied in a total of 16k of ROM.
Atari originally licensed the 6502-assembler code for Microsoft BASIC. This came in two versions, one that was about 7900 bytes that used a 32-bit (6-digit) floating-point number format, and another that was closer to 9000 that included an expanded floating-point format with a 40-bit (9-digit) numbers. The vast majority of 8-bit machines used the larger 9k/40-bit version, and then further expanded it with additional functions for basic input/output. For instance, the BASIC, character set and I/O in the early PET machines was supplied in a total of 16k of ROM.
At line 8 changed one line
When the project was still a games console, Atari had selected an 8k cartridge format because that was an easy size to supply in a single ROM. When the project moved to a computer, a BASIC interpreter was required and Atari naturally licensed MS's code. Atari programmers started with the smaller 8k version and struggled to cut it down enough to fit in the pre-selected 8k cartridge format. That was hard enough of its own, but they really wanted to add additional instructions to take advantage of the Atari's graphics and sound. Eventually, sometime in the summer of 1978, they gave up and went looking for a 3rd party to do it for them.
The Atari machines were originally designed as games consoles that would replace the Atari VCS, and like those machines, software would be supplied on ROM cartridges. ROM was still relatively expensive at the time, so they expanded it from the 4k of the VCS to the luxurious size of 8k. When the project moved to a computer, a BASIC interpreter was required and Atari naturally licensed MS's code. Atari programmers started with the smaller 7900 bytes version and struggled to cut fit it in the pre-selected 8k cartridge format. That was hard enough of its own, but they really wanted to add additional instructions to take advantage of the Atari's graphics and sound. Eventually, sometime in the summer of 1978, they gave up and went looking for a 3rd party to do it for them.
At line 14 changed one line
In order to fit the code into a 8k ROM, two major pieces of code were moved out of the BASIC into the OS ROM. The first was a set of graphics routines to set up the screen, draw lines, and similar tasks. The second was the floating point math system, based on a new implementation of the 6-byte binary-coded-decimal (BCD) format. Both libraries were notoriously slow. Generally, Atari BASIC was among the slowest BASICs of its era, both due to the OS code and two problems involving loops.
In order to fit the code into a 8k ROM, two major pieces of code were moved out of the BASIC into the OS ROM. The first was a set of graphics routines to set up the screen, draw lines, and similar tasks. The second was the floating-point math system, based on a new implementation of the 6-byte binary-coded-decimal (BCD) format SMI had designed for the Z80-based Cromemco machines. Both libraries were notoriously slow. Generally, Atari BASIC was among the slowest BASICs of its era, both due to the OS code and two problems involving loops.
This page (revision-114) was last changed on 24-Feb-2023 14:10 by Andreas Tartz  Top