From e56a44afa95442d2ce88525d30c087d0197b3f7a Mon Sep 17 00:00:00 2001
From: mooz <mooz@blockos.org>
Date: Wed, 7 Nov 2018 20:28:48 +0100
Subject: [PATCH] Added CALF instruction.

---
 l7801.lua   |  4 ++--
 uPD7801.lua | 14 +++++++++++++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/l7801.lua b/l7801.lua
index cd68a43..59bc296 100644
--- a/l7801.lua
+++ b/l7801.lua
@@ -38,7 +38,7 @@ local Keywords_data = {
     'dc',
 }
 local Keywords_7801 = {
-    'block', 'calt', 'dcr', 'jr', 'lxi', 'mvi', 'nop'
+    'block', 'calf', 'calt', 'dcr', 'jr', 'lxi', 'mvi', 'nop'
 }
 local Registers_7801 = {
     a=8,b=8,c=8,d=8,e=8,h=8,l=8,v=8,
@@ -65,7 +65,7 @@ local opcode_implied = lookupify{
     'block', 'dcr', 'nop'
 }
 local opcode_immediate = lookupify{
-    'calt', 'lxi', 'mvi'
+    'calf', 'calt', 'lxi', 'mvi'
 }
 local opcode_relative = lookupify{
     'jr',
diff --git a/uPD7801.lua b/uPD7801.lua
index e0142d0..9c4da8d 100644
--- a/uPD7801.lua
+++ b/uPD7801.lua
@@ -275,6 +275,19 @@ M.calt = function(late, early)
     table.insert(M.section_current.instructions, op)
 end
 
+M.calf = function(late, early)
+    local l65dbg = { info=debug.getinfo(2, 'Sl'), trace=debug.traceback(nil, 1) }
+    local op = { cycles=16 }
+    op.size = function() late,early = M.size_op(late,early) return 2 end
+    op.bin = function() local l65dbg=l65dbg 
+        local x = 0 + M.op_eval_word(late,early)
+        if x < 0x0800 or x > 0xffff then error("subroutine address out of range [0x0800-0xffff]: " .. x) end
+        x = x - 0x0800;
+        return { 0x78 | ((x>>8) & 0x07), x&0xff }
+    end
+    table.insert(M.section_current.instructions, op)
+end
+
 M.jr = function(label)
     local l65dbg = { info=debug.getinfo(2, 'Sl'), trace=debug.traceback(nil, 1) }
     local parent,offset = M.label_current
@@ -312,7 +325,6 @@ return M
 8 bits instructions:
     JRE+ 0x4e xx 17
     JRE- 0x4f xx 17
-    CALF 0x78-0x75 xx 16
 
 16 bits instructions:
     0x48xx