-------------------------------------------------------------------------------
-- Joust2 by Dar (darfpga@aol.fr) (15 March 2022)
-- http://darfpga.blogspot.fr
-- https://sourceforge.net/projects/darfpga/files
-- github.com/darfpga
--
--  Terasic board MAX10 DE10 Lite
-------------------------------------------------------------------------------
-- gen_ram.vhd & io_ps2_keyboard
-------------------------------- 
-- Copyright 2005-2008 by Peter Wendrich (pwsoft@syntiac.com)
-- http://www.syntiac.com/fpga64.html
-------------------------------------------------------------------------------
-- cpu09l - Version : 0128
-- Synthesizable 6809 instruction compatible VHDL CPU core
-- Copyright (C) 2003 - 2010 John Kent
-------------------------------------------------------------------------------
-- cpu68 - Version 9th Jan 2004 0.8
-- 6800/01 compatible CPU core 
-- GNU public license - December 2002 : John E. Kent
-------------------------------------------------------------------------------
-- MC6809
-- Copyright (c) 2016, Greg Miller
---------------------------------------------------------------------------------
-- HC55516/HC55564 Continuously Variable Slope Delta decoder
-- (c)2015 vlait
---------------------------------------------------------------------------------
-- JT51 (YM2151). <http://www.gnu.org/licenses/>.
-- Author: Jose Tejada Gomez. Twitter: @topapate
---------------------------------------------------------------------------------
-- Educational use only
-- Do not redistribute synthetized file with roms
-- Do not redistribute roms whatever the form
-- Use at your own risk
-------------------------------------------------------------------------------
--  Video 15KHz is OK, 
--
--  This is not VGA, you have to use a TV set with SCART plug
--
--    SCART(TV) pin  - signal -  VGA(DE10) pin
--               15  -  red   -  1          
--               11  - green  -  2
--                7  -  blue  -  3  
--           5,9,13  -  gnd   -  5,6,7
--   (comp. sync)20  - csync  -  13 (HS)   
--  (fast commut)16  - commut -  14 (VS)
--            17,18  -  gnd   -  8,10 
--
-------------------------------------------------------------------------------
-- Version 1.0 -- 28/03/2022 -- 
--      add speech board (required loader 1 and loader 2 steps)
-- Version 0.0 -- 05/03/2022 -- 
--	initial version 
-------------------------------------------------------------------------------
--
-- Main features :
--  PS2 keyboard input @gpio pins 35/34 (beware voltage translation/protection)
--  Audio pwm output   @gpio pins 1/3 (beware voltage translation/protection)
--
-- Uses 1 pll for 12MHz and 120MHz generation from 50MHz
--
-- Board key :
--   0 : reset game
--
-- Keyboard players inputs :
--
--   F3 : Add coin
--   F2 : Start 2 players
--   F1 : Start 1 player
--   SPACE       : Flap 
--   RIGHT arrow : Move right P1
--   LEFT  arrow : Move left  P1
--   UP    arrow : Move right P2
--   DOWN  arrow : Move left  P2
--   CTRL        : 
--   W(Z)        : 
--
-- Keyboard Service inputs French(english) :
--
--   A(Q) : advance
--   U(U) : auto/up (!manual/down)
--   H(H) : high score reset
--
-- To enter service mode press 'advance' key while in game over screen
-- Enter service mode to tune game parameters (difficulty ...)
-- Tuning are lost at power OFF, for permanent tuning edit/set parameters
--   within joust2_cmos_ram.vhd and recompile.
--
-------------------------------------------------------------------------------
-- Use make_joust2_proms.bat to build vhd file and bin from binaries
-- Load sdram with external rom bank -> use sdram_loader_de10_lite.sof + key(0)
-------------------------------------------------------------------------------
-- Program sdram content with the 2 joust2 rom loader before programming joust2 
-- game core
--
-- 1) program DE10_lite with joust2 sdram loader 1
-- 2) press key(0) at least once (digit blinks during programming)

-- 3) program DE10_lite with joust2 sdram loader 2
-- 4) press key(0) at least once (digit blinks during programming)

-- 5) program DE10_lite with joust2 core without switching DE10_lite OFF
--
-------------------------------------------------------------------------------
-- Used ROMs by make_joust2_proms.bat

> joust2_prog1
   cpu_2732_ic55_rom2_rev1.4c CRC(08b0d5bd)

> joust2_prog2
   cpu_2732_ic9_rom3_rev2.4d  CRC(951175ce)
   cpu_2732_ic10_rom4_rev2.4f CRC(ba6e0f6c)

> joust2_bank_a
   cpu_2732_ic26_rom19_rev1.10j CRC(4ef5e805)
   cpu_2732_ic24_rom17_rev1.10h CRC(4861f063)
   cpu_2732_ic22_rom15_rev1.9j  CRC(421aafa8)
   cpu_2732_ic20_rom13_rev1.9h  CRC(3432ff55)

> joust2_bank_b
   cpu_2732_ic25_rom18_rev1.10i CRC(47580af5)
   cpu_2732_ic23_rom16_rev1.10g CRC(869b5942)
   cpu_2732_ic21_rom14_rev1.9i  CRC(0bbd867c)
   cpu_2732_ic19_rom12_rev1.9g  CRC(b9221ed1)   

> joust2_bank_c
   cpu_2732_ic18_rom11_rev1.8j CRC(9dc986f9)
   cpu_2732_ic16_rom9_rev2.8h  CRC(56e2b550)
   cpu_2732_ic14_rom7_rev2.6j  CRC(f3bce576)
   cpu_2732_ic12_rom5_rev2.6h  CRC(5f8b4919)

> joust2_bank_d
   cpu_2732_ic17_rom10_rev1.8i CRC(3e01b597)
   cpu_2732_ic15_rom8_rev1.8g  CRC(ff26fb29)
   cpu_2732_ic13_rom6_rev2.6i  CRC(5f107db5)

> joust2_sound
   cpu_2764_ic8_rom1_rev1.0f   CRC(84517c3c)

> joust2_graph1
   vid_27128_ic57_rom20_rev1.8f CRC(572c6b01)

> joust2_graph2
   vid_27128_ic58_rom21_rev1.9f CRC(aa94bf05)

> joust2_graph3
   vid_27128_ic41_rom22_rev1.9d CRC(c41e3daa)

> joust2_decoder
   vid_82s147a_ic60_a-5282-10292.12f CRC(0ea3f7fb)

> joust2_bg_sound_bank_a
    snd_27256_rom23_rev1.u4   CRC(3af6b47d) IC_U4

> joust2_bg_sound_bank_b
    snd_27256_rom24_rev1.u19  CRC(e7f9ed2e) IC_U19

> joust2_bg_sound_bank_c
    snd_27256_rom25_rev1.u20  CRC(c85b29f7) IC_U20

-------------------------------------------------------------------------------
-- Misc. info
-------------------------------------------------------------------------------
-- Main bus access
--  > Main address bus and data bus by CPU 6809
--  > Main address bus and data bus by DMA (blitter) while CPU is halted.
--
-- CPU and DMA can read/write anywhere from/to entire 64K address space
-- including video ram, color palette, tile map, cmos_ram, peripherals, roms,
-- switched rom banks, ...

--
-- Page register control allows to select misc. banked access (rom, ram). 
-------------------------------------------------------------------------------
-- Video ram : 3 banks of 16Kx8 (dram with ras/cas)
--  > interleaved bank access by CPU, 8bits read/write
--  > interleaved bank access by DMA, 8bits read, 2x4bits independent write
--  > simultaneous (3 banks) access by video scanner, 24bits at once
-- 
-- In original hardware, every 1us there is 1 access to video ram for CPU/DMA
-- and 1 access for video scanner. Thus DMA read/write cycle required 2us when
-- reading source is video ram. DMA read/write cycle required only 1us when
-- reading source is not video ram.
--
-- Higher part of video ram is not displayed on screen and is used as working
-- ram by CPU including stack (SP).
-------------------------------------------------------------------------------
-- Foreground (bitmap - video ram)
--  > 24 bits / 1us => 6 horizontal pixels of 4bits (16 colors)
--  > 6 bits register (64 color banks)
-------------------------------------------------------------------------------
-- Background (tile map : tile is 24x16 pixels)
--
--  > 16 horizontal tiles of 4x6 pixels, 16 vertical tiles of 16 pixels.
--  > map ram 2048x8
--      in  : 7 bits horizontal (4 bits + scroll) + 4 bits vertical
--      out : 128 possible tiles + flip control
--
--  > Graphics 3x8Kx8 roms
--      in  : 2 bits horizontal + 4 bits vertical + 7 bits tile code 
--      out : 24 bits = 6 pixels x 4 bits
--
--  > 24 bits / 1us => 6 horizontal pixels of 4bits (16 colors)
--  > 6 bits register (64 color banks)
-------------------------------------------------------------------------------
-- Palette 1024 colors x 16 bits
--  > in  10 bits from foreground or background data
--  > out 4 bits red, 4 bits green, 4 bits blue, 4 bits intensity 
-------------------------------------------------------------------------------