Some notes on the Dave Platt's A-code source of adv550
                       (the 18 Sep 1984 version)

                       Mike Arnautov, 04 Nov 2001

The only change I had to make to DP's A-code to make it work with my
A-code engine (version 11), was to move the block of DEFINE statements
from where it was (between the AT and the ACTION sections) to between
the VARIABLE and the LABEL sections. The current engine expects all purely
declarative statements to precede any code, and the LABEL section in the
adv550 code is the first to specify code.

The NEWS text mentions cave maps being available from Dave Platt at
Honeywell in L.A. The address is presumably obsolete, but I leave it in
for historical reasons. Following the lead of the Ken Welsch C bundle,
based on a simplified (earlier?) version of adv550 A-code source, I am
providing the maps as a part of this bundle. 

When processing DP's A-code source with a tool fussier than Dave's A-code
"munger", a number of declarations are identified as redundant. Here is
a summary of all such declarations.

The below texts are not used. I do not know whether they represent
abandoned expansion plans by DP, but most of them were subsequently used
by me when merging adv440 and adv550 into adv660.

TEXT     IAMUNSURE
TEXT     CANTAPPLY
TEXT     NOCANLOOK
TEXT     WMEANSWEST
TEXT     BESERIOUS
TEXT     CANTLOCKIT
TEXT     ITWASLOCKED
TEXT     WASUNLOCKED
TEXT     WHERE?
TEXT     GRATENEEDSKEYS
TEXT     INFOREST
TEXT     NEEDDYNAMITE
TEXT     FEETAREWET
TEXT     CANTPOUR
TEXT     WATCHIT
TEXT     QUIT.NOW?
TEXT     START.OVER
TEXT     ON.WHAT?
TEXT     THIS.IS.A.CLUE
TEXT     UNCHANGED
TEXT     I.DONT.UNDERSTAND
TEXT     SHATTER.MIRROR
TEXT     CANT.READ.OYSTER
TEXT     OYSTER.IS.BARE

Texts in the below group are also unused. It would seem that DP did
not remove them when removing playing restrictions.

TEXT     ETMF.TOO.HIGH
TEXT     TOO.MANY.USERS
TEXT     RESTORE.ETMF
TEXT     RESTORE.USERS

The following five texts may appear to be not used, but only their names
are not. The texts themselves are used as anonymous texts, via an offset
from a previous text. (They really ought to be declared as anonymous.)

TEXT     NEW.EFFECT
TEXT     PLUMMET1
TEXT     PLUMMET2
TEXT     PLUMMET3
TEXT     SO.YOU.ARE

Finally, there is a symbolic constant, a variable and a procedure, which
are not used. In the case of the CLOSE.CREDIT constant, the code simply
hard-wires the value of 20, instead of using the symbolic constant.

SYNON    20,CLOSE.CREDIT         Definition not used
VARIABLE EXPLODE.THE.WELLHOUSE   Variable not used
LABEL    READ.MACHINE            Procedure not used




                                        Mike Arnautov
                                        mla@britishlibrary.net
                                        04 Nov 2001