diff --git a/ncurses/base/new_pair.c b/ncurses/base/new_pair.c
new file mode 100644
index 0000000..70866c6
--- /dev/null
+++ b/ncurses/base/new_pair.c
@@ -0,0 +1,393 @@
+/****************************************************************************
+ * Copyright 2018-2020,2021 Thomas E. Dickey                                *
+ * Copyright 2017 Free Software Foundation, Inc.                            *
+ *                                                                          *
+ * Permission is hereby granted, free of charge, to any person obtaining a  *
+ * copy of this software and associated documentation files (the            *
+ * "Software"), to deal in the Software without restriction, including      *
+ * without limitation the rights to use, copy, modify, merge, publish,      *
+ * distribute, distribute with modifications, sublicense, and/or sell       *
+ * copies of the Software, and to permit persons to whom the Software is    *
+ * furnished to do so, subject to the following conditions:                 *
+ *                                                                          *
+ * The above copyright notice and this permission notice shall be included  *
+ * in all copies or substantial portions of the Software.                   *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
+ *                                                                          *
+ * Except as contained in this notice, the name(s) of the above copyright   *
+ * holders shall not be used in advertising or otherwise to promote the     *
+ * sale, use or other dealings in this Software without prior written       *
+ * authorization.                                                           *
+ ****************************************************************************/
+
+/****************************************************************************
+ *  Author: Thomas E. Dickey                                                *
+ ****************************************************************************/
+
+/* new_pair.c
+ *
+ * New color-pair functions, alloc_pair and free_pair
+ */
+
+#define NEW_PAIR_INTERNAL 1
+#include <curses.priv.h>
+
+#ifndef CUR
+#define CUR SP_TERMTYPE
+#endif
+
+#ifdef USE_TERM_DRIVER
+#define MaxColors      InfoOf(SP_PARM).maxcolors
+#else
+#define MaxColors      max_colors
+#endif
+
+#if NCURSES_EXT_COLORS
+
+/* fix redefinition versys tic.h */
+#undef entry
+#define entry my_entry
+#undef ENTRY
+#define ENTRY my_ENTRY
+
+#include <search.h>
+
+#endif
+
+MODULE_ID("$Id: new_pair.c,v 1.23 2021/08/16 22:11:26 tom Exp $")
+
+#if NCURSES_EXT_COLORS
+
+#ifdef NEW_PAIR_DEBUG
+
+static int
+prev_len(SCREEN *sp, int pair)
+{
+    int result = 1;
+    int base = pair;
+    colorpair_t *list = sp->_color_pairs;
+    while (list[pair].prev != base) {
+	result++;
+	pair = list[pair].prev;
+    }
+    return result;
+}
+
+static int
+next_len(SCREEN *sp, int pair)
+{
+    int result = 1;
+    int base = pair;
+    colorpair_t *list = sp->_color_pairs;
+    while (list[pair].next != base) {
+	result++;
+	pair = list[pair].next;
+    }
+    return result;
+}
+
+/*
+ * Trace the contents of LRU color-pairs.
+ */
+static void
+dumpit(SCREEN *sp, int pair, const char *tag)
+{
+    colorpair_t *list = sp->_color_pairs;
+    char bigbuf[256 * 20];
+    char *p = bigbuf;
+    int n;
+    size_t have = sizeof(bigbuf);
+
+    _nc_STRCPY(p, tag, have);
+    for (n = 0; n < sp->_pair_alloc; ++n) {
+	if (list[n].mode != cpFREE) {
+	    p += strlen(p);
+	    if ((size_t) (p - bigbuf) + 50 > have)
+		break;
+	    _nc_SPRINTF(p, _nc_SLIMIT(have - (p - bigbuf))
+			" %d%c(%d,%d)",
+			n, n == pair ? '@' : ':', list[n].next, list[n].prev);
+	}
+    }
+    T(("(%d/%d) %ld - %s",
+       next_len(sp, 0),
+       prev_len(sp, 0),
+       strlen(bigbuf), bigbuf));
+
+    if (next_len(sp, 0) != prev_len(sp, 0)) {
+	endwin();
+	ExitProgram(EXIT_FAILURE);
+    }
+}
+#else
+#define dumpit(sp, pair, tag)	/* nothing */
+#endif
+
+static int
+compare_data(const void *a, const void *b)
+{
+    const colorpair_t *p = (const colorpair_t *) a;
+    const colorpair_t *q = (const colorpair_t *) b;
+    return ((p->fg == q->fg)
+	    ? (p->bg - q->bg)
+	    : (p->fg - q->fg));
+}
+
+static int
+_nc_find_color_pair(SCREEN *sp, int fg, int bg)
+{
+    colorpair_t find;
+    int result = -1;
+
+    find.fg = fg;
+    find.bg = bg;
+    if (sp != 0) {
+	void *pp;
+	if ((pp = tfind(&find, &sp->_ordered_pairs, compare_data)) != 0) {
+	    colorpair_t *temp = *(colorpair_t **) pp;
+	    result = (int) (temp - sp->_color_pairs);
+	}
+    }
+    return result;
+}
+
+static void
+delink_color_pair(SCREEN *sp, int pair)
+{
+    colorpair_t *list = sp->_color_pairs;
+    int prev = list[pair].prev;
+    int next = list[pair].next;
+
+    /* delink this from its current location */
+    if (list[prev].next == pair &&
+	list[next].prev == pair) {
+	list[prev].next = next;
+	list[next].prev = prev;
+	dumpit(sp, pair, "delinked");
+    }
+}
+
+/*
+ * Discard all nodes in the fast-index.
+ */
+NCURSES_EXPORT(void)
+_nc_free_ordered_pairs(SCREEN *sp)
+{
+    if (sp && sp->_ordered_pairs && sp->_pair_alloc) {
+	int n;
+	for (n = 0; n < sp->_pair_alloc; ++n) {
+	    tdelete(&sp->_color_pairs[n], &sp->_ordered_pairs, compare_data);
+	}
+    }
+}
+
+/*
+ * Use this call to update the fast-index when modifying an entry in the color
+ * pair table.
+ */
+NCURSES_EXPORT(void)
+_nc_reset_color_pair(SCREEN *sp, int pair, colorpair_t * next)
+{
+    colorpair_t *last;
+
+    if (ValidPair(sp, pair)) {
+	bool used;
+
+	ReservePairs(sp, pair);
+	last = &(sp->_color_pairs[pair]);
+	delink_color_pair(sp, pair);
+	if (last->mode > cpFREE &&
+	    (last->fg != next->fg || last->bg != next->bg)) {
+	    /* remove the old entry from fast index */
+	    tdelete(last, &sp->_ordered_pairs, compare_data);
+	    used = FALSE;
+	} else {
+	    used = (last->mode != cpFREE);
+	}
+	if (!used) {
+	    /* create a new entry in fast index */
+	    *last = *next;
+	    tsearch(last, &sp->_ordered_pairs, compare_data);
+	}
+    }
+}
+
+/*
+ * Use this call to relink the newest pair to the front of the list, keeping
+ * "0" first.
+ */
+NCURSES_EXPORT(void)
+_nc_set_color_pair(SCREEN *sp, int pair, int mode)
+{
+    if (ValidPair(sp, pair)) {
+	colorpair_t *list = sp->_color_pairs;
+	dumpit(sp, pair, "SET_PAIR");
+	list[0].mode = cpKEEP;
+	if (list[pair].mode <= cpFREE)
+	    sp->_pairs_used++;
+	list[pair].mode = mode;
+	if (list[0].next != pair) {
+	    /* link it at the front of the list */
+	    list[pair].next = list[0].next;
+	    list[list[pair].next].prev = pair;
+	    list[pair].prev = 0;
+	    list[0].next = pair;
+	}
+	dumpit(sp, pair, "...after");
+    }
+}
+
+/*
+ * If we reallocate the color-pair array, we have to adjust the fast-index.
+ */
+NCURSES_EXPORT(void)
+_nc_copy_pairs(SCREEN *sp, colorpair_t * target, colorpair_t * source, int length)
+{
+    int n;
+    for (n = 0; n < length; ++n) {
+	void *find = tfind(source + n, &sp->_ordered_pairs, compare_data);
+	if (find != 0) {
+	    tdelete(source + n, &sp->_ordered_pairs, compare_data);
+	    tsearch(target + n, &sp->_ordered_pairs, compare_data);
+	}
+    }
+}
+
+NCURSES_EXPORT(int)
+NCURSES_SP_NAME(alloc_pair) (NCURSES_SP_DCLx int fg, int bg)
+{
+    int pair;
+
+    T((T_CALLED("alloc_pair(%d,%d)"), fg, bg));
+    if (SP_PARM == 0) {
+	pair = -1;
+    } else if ((pair = _nc_find_color_pair(SP_PARM, fg, bg)) < 0) {
+	/*
+	 * Check if all of the slots have been used.  If not, find one and
+	 * use that.
+	 */
+	if (SP_PARM->_pairs_used + 1 < SP_PARM->_pair_limit) {
+	    bool found = FALSE;
+	    int hint = SP_PARM->_recent_pair;
+
+	    /*
+	     * The linear search is done to allow mixing calls to init_pair()
+	     * and alloc_pair().  The former can make gaps...
+	     */
+	    for (pair = hint + 1; pair < SP_PARM->_pair_alloc; pair++) {
+		if (SP_PARM->_color_pairs[pair].mode == cpFREE) {
+		    T(("found gap %d", pair));
+		    found = TRUE;
+		    break;
+		}
+	    }
+	    if (!found && (SP_PARM->_pair_alloc < SP_PARM->_pair_limit)) {
+		pair = SP_PARM->_pair_alloc;
+		ReservePairs(SP_PARM, pair);
+		if (SP_PARM->_color_pairs == 0) {
+		    pair = -1;
+		} else {
+		    found = TRUE;
+		}
+	    }
+	    if (!found && SP_PARM->_color_pairs != NULL) {
+		for (pair = 1; pair <= hint; pair++) {
+		    if (SP_PARM->_color_pairs[pair].mode == cpFREE) {
+			T(("found gap %d", pair));
+			found = TRUE;
+			break;
+		    }
+		}
+	    }
+	    if (found) {
+		SP_PARM->_recent_pair = pair;
+	    } else {
+		pair = ERR;
+	    }
+	} else {
+	    /* reuse the oldest one */
+	    pair = SP_PARM->_color_pairs[0].prev;
+	    T(("reusing %d", pair));
+	}
+
+	if (_nc_init_pair(SP_PARM, pair, fg, bg) == ERR)
+	    pair = ERR;
+    }
+    returnCode(pair);
+}
+
+NCURSES_EXPORT(int)
+NCURSES_SP_NAME(find_pair) (NCURSES_SP_DCLx int fg, int bg)
+{
+    int pair;
+
+    T((T_CALLED("find_pair(%d,%d)"), fg, bg));
+    pair = _nc_find_color_pair(SP_PARM, fg, bg);
+    returnCode(pair);
+}
+
+NCURSES_EXPORT(int)
+NCURSES_SP_NAME(free_pair) (NCURSES_SP_DCLx int pair)
+{
+    int result = ERR;
+    T((T_CALLED("free_pair(%d)"), pair));
+    if (ValidPair(SP_PARM, pair) && pair < SP_PARM->_pair_alloc) {
+	colorpair_t *cp = &(SP_PARM->_color_pairs[pair]);
+	if (pair != 0) {
+	    _nc_change_pair(SP_PARM, pair);
+	    delink_color_pair(SP_PARM, pair);
+	    tdelete(cp, &SP_PARM->_ordered_pairs, compare_data);
+	    cp->mode = cpFREE;
+	    result = OK;
+	    SP_PARM->_pairs_used--;
+	}
+    }
+    returnCode(result);
+}
+
+#if NCURSES_SP_FUNCS
+NCURSES_EXPORT(int)
+alloc_pair(int f, int b)
+{
+    return NCURSES_SP_NAME(alloc_pair) (CURRENT_SCREEN, f, b);
+}
+
+NCURSES_EXPORT(int)
+find_pair(int f, int b)
+{
+    return NCURSES_SP_NAME(find_pair) (CURRENT_SCREEN, f, b);
+}
+
+NCURSES_EXPORT(int)
+free_pair(int pair)
+{
+    return NCURSES_SP_NAME(free_pair) (CURRENT_SCREEN, pair);
+}
+#endif
+
+#if NO_LEAKS
+NCURSES_EXPORT(void)
+_nc_new_pair_leaks(SCREEN *sp)
+{
+    if (sp->_color_pairs) {
+	while (sp->_color_pairs[0].next) {
+	    free_pair(sp->_color_pairs[0].next);
+	}
+    }
+}
+#endif
+
+#else
+void _nc_new_pair(void);
+void
+_nc_new_pair(void)
+{
+}
+#endif /* NCURSES_EXT_COLORS */