[Coco] Cryptic BASIC program

[Arthur Flexser]

On Fri, Sep 25, 2015 at 11:18 PM, Darren A <mechacoco at gmail.com> wrote:

>
> It is not a good substitute for a real RAM test program. It merely checks
> the jumper setting which Basic uses at initialization time to decide how to
> configure the SAM chip.  I'm not sure if the CoCo will even boot correctly
> when the SAM is configured for the wrong type of RAM chip.
>

I recall you could fool a 32/64K CoCo 1 into setting the SAM for 4K by
pressing the reset button with shift and break held down, so
apparently CoCo Basic will tolerate a wrongly set SAM configuration in at
least some cases.

(This was the basis of the shift-break-reset method of breaking out of a
copy-protected program, allowing certain special methods of removing the
copy protection to be employed.  Not usable with Color Basic 1.2 (?) and
above due to the elimination of checking for the 4K possibility in later
versions of Basic's warm start routine.  After shift-break-reset, most
commands give an out-of memory error in the 4K configuration, but CLOADM
and EXEC work, so you can regain control of the machine and switch back to
64K SAM mode.)

Art