Self modifying code, lambda calculus - Re: ENIAC programming

Liam Proven lproven at
Sun Sep 20 09:47:50 CDT 2015

On 20 September 2015 at 13:54, Peter Coghlan <cctalk at> wrote:
> BBC BASIC (when running on a BBC Micro at least) does clear (most) variables
> when a program is loaded.  Most variables are stored in memory above the
> program and if a small program was replaced by a larger program, some could get
> overwritten.  Acorn may have decided that it was too much trouble to figure out
> whether or which variables might be affected and that it was easier to be safe
> by clearing them every time a program is loaded.
> BBC BASIC (on a BBC Micro) doesn't have a MERGE command or equivelant either
> but it is possible to merge programs together using slight hackery.  However,
> once BASIC is made aware of the change, it will clear the variables so a
> certain level of deviousness is required to do stuff like overlays.

Hmmm. I'm now wondering if the command was CHAIN not LOAD...

Liam Proven • Profile:
Email: lproven at • GMail/G+/Twitter/Flickr/Facebook: lproven
MSN: lproven at • Skype/AIM/Yahoo/LinkedIn: liamproven
Cell/Mobiles: +44 7939-087884 (UK) • +420 702 829 053 (ČR)

More information about the cctalk mailing list