The original Altair BASIC came in three versions; 4k, 8k and Extended. The numbers referred to the amount of RAM required to run it, as BASIC was loaded to RAM from paper tape. The 4k version running in 4k of RAM had a whopping 790 bytes free.

The 4k and 8k versions used a 6-byte floating point format. The 4k version lacked strings and some other less important features. The 8k version added strings, some more math functions, and peek and poke. Extended added a "double precision" floating point format. I think the double was actually the 9-byte format found in later 6502 versions, but I'm not sure.

UPDATE: the double-precision system was a 64-bit format. The 40-bit format became the standard during the 6502 port.

I suspect, as you do, that the code was deliberately "copied" as much as possible with an eye to ease of porting rather than code size or performance. New processors were popping up continuously, and tuning for each one would not only be difficult but ultimately fruitless as some of these would be doomed to die. Like the 6800.

BTW, supercat, are you playing with the source in your own versions?

The original Altair BASIC came in three versions; 4k, 8k and Extended. The numbers referred to the amount of RAM required to run it, as BASIC was loaded to RAM from paper tape. The 4k version running in 4k of RAM had a whopping 790 bytes free.

The 4k and 8k versions used a 4-byte (6-digit) floating point format. The 4k version lacked string variables and some other less important features. The 8k version added strings, some more math functions, and peek and poke. Extended added a "double precision" floating point format. I think the double was actually the 6-byte (9-digit) format found in later 6502 versions, but I'm not sure.

UPDATE: the double-precision system was a 64-bit format. The 40-bit format became the standard during the 6502 port, largely replacing both earlier formats.

I suspect, as you do, that the code was deliberately "copied" as much as possible with an eye to ease of porting rather than code size or performance. New processors were popping up continuously, and tuning for each one would not only be difficult but ultimately fruitless as some of these would be doomed to die. Like the 6800.

BTW, supercat, are you playing with the source in your own versions?

The original Altair BASIC came in three versions; 4k, 8k and Extended. The numbers referred to the amount of RAM required to run it, as BASIC was loaded to RAM from paper tape. The 4k version running in 4k of RAM had a whopping 790 bytes free.

The 4k and 8k versions used a 6-byte floating point format. The 4k version lacked strings and some other less important features. The 8k version added strings, some more math functions, and peek and poke. Extended added a "double precision" floating point format. I think the double was actually the 9-byte format found in later 6502 versions, but I'm not sure.

I suspect, as you do, that the code was deliberately "copied" as much as possible with an eye to ease of porting rather than code size or performance. New processors were popping up continuously, and tuning for each one would not only be difficult but ultimately fruitless as some of these would be doomed to die.

BTW, supercat, are you playing with the source in your own versions?

The original Altair BASIC came in three versions; 4k, 8k and Extended. The numbers referred to the amount of RAM required to run it, as BASIC was loaded to RAM from paper tape. The 4k version running in 4k of RAM had a whopping 790 bytes free.

The 4k and 8k versions used a 6-byte floating point format. The 4k version lacked strings and some other less important features. The 8k version added strings, some more math functions, and peek and poke. Extended added a "double precision" floating point format. I think the double was actually the 9-byte format found in later 6502 versions, but I'm not sure.

UPDATE: the double-precision system was a 64-bit format. The 40-bit format became the standard during the 6502 port.

I suspect, as you do, that the code was deliberately "copied" as much as possible with an eye to ease of porting rather than code size or performance. New processors were popping up continuously, and tuning for each one would not only be difficult but ultimately fruitless as some of these would be doomed to die. Like the 6800.

BTW, supercat, are you playing with the source in your own versions?