[z-machine] Inconsistent use of header flags

[Michael S. Greger]

I noticed while testing my interpreter that the game "Balances", which
is a V5 game, depends on bit 1 in the header section Flags1 to properly
display its status line. According to the Z-Machine specification this
bit controls whether a game is score based or time based in V1-V3 games
only. From V4 and up this bit is set to indicate the interpreter can
display pictures. My interpreter notices the game is V5 and sets the
bit, causing the status line to be displayed improperly. Technically
this would be a bug, but I wonder how many other Inform games may have
it.  I took a look at Frotz's source to see how it avoids the situation
and found it only sets the bit to indicate picture capability in V6
ONLY, thus the problem never shows itself there. If this is common to
all early Inform games, then should the specification be altered to
match the de facto standard?

 

Thanks,

MikeG

 

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