; ------------------------------------------------------------------ RAM
; The work area: $1900 bytes from WORK, which the includer sets (a page
; boundary). WORK+$400 to +$7ff is free for the caller.
W       equ WORK+$0000       ; the move generator's board
ROOT    equ WORK+$0040       ; the position to play from
ROOT2   equ WORK+$0080       ; the opponent's position, replying
CAND    equ WORK+$00c0       ; a candidate play's position
PA      equ WORK+$0100       ; a position being scored: PA on roll
PB      equ WORK+$0120
RESULT  equ WORK+$0140       ; the chosen play's position
STEPS   equ WORK+$0200       ; per step of the play being generated: point, hit
GDIE    equ WORK+$0210       ; the die of each step
KEY     equ WORK+$0220       ; a play's hash
NEWKEY  equ WORK+$0230       ; a play for a list: key (5), steps (8)
NEWSTEPS equ NEWKEY+5
WINSTEPS equ WORK+$0240      ; a play bearing off the last checker
VARS    equ WORK+$0280       ; single variables (below)
HSTAMP  equ WORK+$1800       ; plays of a non-double generated: a stamp, then
                        ; their hash's 4 bytes a page each
RTAB    equ WORK+$0800       ; hash values: 51 of 4 bytes
NST     equ WORK+$0340       ; PA/PB's inputs beyond the points (as a base's)
FEAT    equ WORK+$0350       ; PA/PB's gnubg features (at a base's offset)
ECACHE  equ WORK+$03a0       ; each half's points held, and escapes from them
SUMS    equ WORK+$0900       ; a net's first-layer sums (lo, hi)
RB_FILTER equ WORK+$0a00     ; the nets' bases, a page each
RB_RACE equ WORK+$0b00
RB_REPLY equ WORK+$0c00
RB_CONTACT equ WORK+$0d00
SIDEX   equ WORK+$1210       ; features: the side, with zeros around
SIDEY   equ WORK+$1250       ; and its opponent
BX      equ WORK+$1290       ; their points held (two or more), 0 or 1
BY      equ WORK+$12d0
SHOTP   equ WORK+$1300       ; shots: page of
TB      equ WORK+$1300       ; blots to hit, by the hitter's index
EL      equ WORK+$1340       ; points that may hit
YB      equ WORK+$1380       ; opponent's points held, by the hitter's index
DK      equ WORK+$13c0       ; direct shot per die: the highest hitter
DM      equ WORK+$13c8       ; and how many hit (1, 2)
TOP12   equ WORK+$1400       ; lists of plays: count, capacity, then 16 each
TOP2    equ WORK+$1500
TOP5    equ WORK+$1600
TOP1    equ WORK+$1700
WORKEND equ WORK+$1900       ; the end of what init clears
WORKTOP equ WORK+$1d00       ; the end of all the engine uses (HSTAMP's pages)

; Variables.
GROOT   equ VARS+0      ; the board being generated from (2)
GCOUNT  equ VARS+2      ; plays generated (2)
GSP     equ VARS+4      ; the stack to leave the search with (2)
LEAFFN  equ VARS+6      ; the move generator's handler of a play (2)
USERFN  equ VARS+8      ; the caller's (2)
GTARGET equ VARS+10
GMAX    equ VARS+11
GEMIT   equ VARS+12
GDOUBLE equ VARS+13
GMAXA   equ VARS+14
GENID   equ VARS+15     ; the move generator's search number
DHI     equ VARS+16     ; the dice, larger first
DLO     equ VARS+17
WIN     equ VARS+18     ; a play bearing off the last checker was seen
CURLIST equ VARS+19     ; the list plays go into (2)
CURIDX  equ VARS+21     ; a play's place in generation order (2)
RES     equ VARS+23     ; a net's score (3)
NETK    equ VARS+26     ; rows added to the sums, net (2)
NETD    equ VARS+28
W2P     equ VARS+29     ; (2)
TOTAL   equ VARS+31     ; a candidate's sum over the rolls (4)
BEST    equ VARS+35     ; (4)
BESTI   equ VARS+39
RA      equ VARS+40
RB      equ VARS+41
CANDI   equ VARS+42
T1      equ VARS+44     ; features' scratch (2 each)
T2      equ VARS+46
T3      equ VARS+48
T7      equ VARS+50
T4      equ VARS+52
T5      equ VARS+53
TM      equ VARS+54
TA      equ VARS+55
TP      equ VARS+56
TI      equ VARS+57
TX      equ VARS+58
HYI     equ VARS+59
NOB     equ VARS+60
MINA    equ VARS+61
MINC    equ VARS+62
SNP     equ VARS+63     ; shots: pips (2)
SN1     equ VARS+65
SN2     equ VARS+66
SSTART  equ VARS+67
RNCH    equ VARS+68
RNP     equ VARS+69
RNEED   equ VARS+70
RD      equ VARS+71
RD1     equ VARS+72
RK0     equ VARS+73
OFFN    equ VARS+74
OFFANY  equ VARS+75
OFFS    equ VARS+76     ; (3)
ESCA    equ VARS+79
PHAND   equ VARS+80     ; (2)
DHAND   equ VARS+82     ; (2)
SCORER  equ VARS+84     ; a list's second stage (2)
LISTP   equ VARS+86     ; (2)
RPAGE   equ VARS+88     ; the page of the net's base
SIDE    equ VARS+89
PTOLD   equ VARS+90
PTNEW   equ VARS+91
FSCORE  equ VARS+92     ; the filter's score of W turned (2)
FHIT    equ VARS+94
FDIE    equ VARS+95
ROWB    equ VARS+96     ; a point's first row (2)
UD      equ VARS+98     ; a point's inputs' changes (4)
WINPOSS equ VARS+102    ; a play may bear off the last checker
BARM    equ VARS+103    ; shots: not two or more on the bar
SPSAVE  equ VARS+104    ; (2)
GKEYED  equ VARS+106    ; plays hashed
GPRUNE  equ VARS+107    ; second-order plays repeating the first skipped
PLYBY   equ VARS+108    ; the lookahead's replies chosen by the contact net
BLIST   equ SHOTP+$d0   ; blots to hit, highest first, then $ff

OPPOFF  equ 32