Date   : Mon, 28 Jan 2013 01:41:56 +0000
From   : jgh@... (J.G.Harston)
Subject: Commodore 64 BBC BASIC

Rick Murray wrote:
> If your host OS doesn't provide these services, or does so in a
> completely alien way, it will take correspondingly more coffee to
> provide the expected language features. I can imagine twice the
> size...

Comparing with CP/M BBC BASIC, the language takes 12K and the veneer 
between the language and the operating system is 3K. Quite neatly as it 
meant I could fit Z80 BASIC and a OS veneer into a 16K ROM image for the 
Spectrum.

Comparing with 6502 BBC BASIC targetted to the System/Atom which also 
don't have BBC MOS entry points, the extra code is about 1/2K, 
compensated for by dropping some code, for example, ENVELOPE just reads 
14 numbers and discards them instead of lots of stack twiddling to build 
a control block to call OSWORD with.

 From that, and from examining the Commodore Kernal API about 20 years 
ago, I would have expected 16K for the language and maybe another 3K/4K 
for the interface veneer.

I might dig out my paper notes from my brief porting attempt 20 years 
ago and re-do it properly.

-- 
J.G.Harston - jgh@...      - mdfs.net