From 0438cb92fe9046ded7fed1669236b362978ee707 Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Mon, 20 Apr 2020 23:06:39 -0400
Subject: [PATCH] Add word "ROLL"

---
 blk/046             |   4 ++--
 emul/forth/z80c.bin | Bin 2217 -> 2240 bytes
 forth/boot.z80      |  21 +++++++++++++++++++++
 forth/core.fs       |   7 +++++++
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/blk/046 b/blk/046
index efc468f..aa50826 100644
--- a/blk/046
+++ b/blk/046
@@ -11,6 +11,6 @@ SWAP        a b -- b a
 2SWAP       a b c d -- c d a b
 PICK        Pick nth item from stack. "0 PICK" = DUP,
             "1 PICK" = OVER.
-
-
+ROLL        Rotate PSP over n items. "1 ROLL" = SWAP,
+            "2 ROLL" = ROT. 0 is noop.
 
diff --git a/emul/forth/z80c.bin b/emul/forth/z80c.bin
index 6cd8124ad38134e811e5cc6b6282fa60bf6b2760..e260c9c54e49fd8c0487c0aff005de74b96c7772 100644
GIT binary patch
delta 1031
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z?xg9in{J}3ETj+wTdG+JT^d{of(1d)jZ_yRF5JZP-lXUznS1Vi=iYPfeI9%heDQ~!
zjw~<E&qqU~pZuH}JMT>O_kVx2*F(dp!bI20CVQ{A4aK4>*GI3~25E*#e)`HSiY(16
z-=FJ?2FVXBAhB!de7c=DVlLxkA)il=JAGbF?tiS4d`3)5sUW(0Z=o1%C*2rDTxU6u
z=L#9814J(W&Eu}B^Dt$`opgR8pLQsx)z~VtXw=H)oiIlFrOs*=UGft%hWRdrO?aQ1
zd;|F9fW*r(7)l%=1@krCEu^NGiZipb9cW!)CWYv!R)V@3D`NzchG<`@u-BUFftvtD
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zd|hL8)QER$`0{cG&9aNh*H{ftJo@NOc-O1%Dka$b1TvC|4k_v=3{I)SngIivdthf=
z6~BADM~lPi<iH6O3Zx+MY73vVN4iOcEg>4_RcWD<oy_J_$6(F6t5?{&RyzwaZ2Hl(
zNTg56T^nfoMQ^aUTIK7qwnRUhgNjKaW09SlxN#Pho*_GuNe7QbRc_NaaNU|)SXq8J
z6^1S`T%8U0#Q!$Dz~C-`eMJD`K(G^iNB1J3DI(uS&*81&%lWK-htf%H0)qL+sVoi&
z*2sfWZCD-v*DADpLjTB}#l@9GGzJcnV$wx1Y#oQtP)t`sqL-D;Iw7f9K~W5zh7Wfl
zuQC8c%;=HGtj8>~CW!?JG&7zNXDl`^Mi6E^!{pa9&iHLfZ&F3C=+H7YmQGEL1hIx~
zUIgzWdVu@BXwYNh4B;O252`Tog4p-EPdL7#dz!m(tR??p3yxA7huTu@x9KBvPsfS<
E1r@m7_y7O^

delta 966
zcmYjPO-NKx82#>h_uUySpHAf%$j~?hIpTywP)w8J8>bp@ethqV^oN+56NH+L3t?b#
zW8q>px*d^rK@34j@E~yEvRu_Bi1sA}xob0>d!JI9nfIOhecwIj+_M{c6?*fB8J9-J
zi|5{kwa;30N3-b0=<rR)B*TnSkoLJny^B*zPiOn$AqoO(RoJbJooOSEnyWfJZrho>
z+voR;{f~7}!0a*-Iu<>AG(Qt>BVqQT_E-|j$Hud6I~JArcOI$gzw{Vo^KQm2+8LLU
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z<#gGfpbGj=VQq~IQR3@tPxC;(#69-Ts57}etfm{xLyw$W$CrP0&@5NMe4RBg;;)b2
zfp<b|Yjd#q31p;G?Ml>17@W|hHT@<u>##GT%iq^rHzKe)-QS5ui3}>dc7#tjLt)Zk
zOAmGPnzGO>Ocd;q)39b)h&p>Owl@w$cXgkC5+7MaukmGt&e88?Sc{UW-quMMZ(qQ(
z`O>!(MFHU!)wn}Hnik!ioi8t~+>b$lq~Wp7fc&pRwWR358(GUF>}hLaOZb%}-;2>J
zODplKnEfe|0qb8RI;cfLu=xy?Wn^H2ijMBU+(Vw&_z*Y??zjl%dU)R*aJ~r6a<Nq?
zxIHSh8jvo~h#fnvvUZ3rN$7Y2rw<ku%Bi?Ijgquo&Sdjh8BY1073Po>{sJsVvu^$#
z)<2FSQ)^;PfOsyK85s)6-0>XtKBGyb_L@nn=6SNvw5v<glJXUo1Jd0s;p+<{g2mwR
W6&$S&;s=FLoC-Sh6&_DsCiWMVKE}iV

diff --git a/forth/boot.z80 b/forth/boot.z80
index 7b8b6d3..60df6c5 100644
--- a/forth/boot.z80
+++ b/forth/boot.z80
@@ -403,6 +403,27 @@ CODE PICK
     BC PUSHqq,
 ;CODE
 
+( this is only a part of ROLL, the other part is performed in
+  high level Forth. This receives from PSP the number of bytes
+  to copy and then performs A move-by-2 operation from SP.
+  This copies SP's TOS and overwrites the last item involved.
+
+  For example, if stack is "1 2 3 4", calling with "4" would
+  result in the stack "1 3 4 4". Never call with 0, there is
+  no sanity check.
+)
+CODE (roll)
+    HL POPqq,
+    B H LDrr,
+    C L LDrr,
+    SP ADDHLss,
+    D H LDrr,
+    E L LDrr,
+    HL DECss,
+    HL DECss,
+    LDDR,
+;CODE
+
 ( a b -- a b a b )
 CODE 2DUP
     HL POPqq,       ( B )
diff --git a/forth/core.fs b/forth/core.fs
index 1b4c7d5..584ea2cd 100644
--- a/forth/core.fs
+++ b/forth/core.fs
@@ -55,6 +55,13 @@
     H@ 2-          ( push a. -2 for allot offset )
 ; IMMEDIATE
 
+: ROLL
+    DUP NOT IF EXIT THEN
+    1+ DUP PICK          ( n val )
+    SWAP 2 * (roll)      ( val )
+    SWAP DROP
+;
+
 ( During a CASE, the stack grows by 1 at each ENDOF so that
   we can fill all those ENDOF branching addrs. So that we
   know when to stop, we put a 0 on PSP. That's our stopgap. )