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103 | ---------------------------------------------------------------- {{{ ----------
--: Copyright © 2020 … 2022 Martin Krischik «krischik@users.sourceforge.net»
-------------------------------------------------------------------------------
--: This library is free software; you can redistribute it and/or modify it
--: under the terms of the GNU Library General Public License as published by
--: the Free Software Foundation; either version 2 of the License, or (at your
--: option) any later version.
--:
--: This library is distributed in the hope that it will be useful, but WITHOUT
--: ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
--: FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
--: License for more details.
--:
--: You should have received a copy of the GNU Library General Public License
--: along with this library; if not, write to the Free Software Foundation,
--: Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
---------------------------------------------------------------- }}} ----------
pragma License (Modified_Gpl);
pragma Ada_2022;
with Ada.Command_Line;
with Ada.IO_Exceptions;
with Ada.Exceptions;
with Ada.Sequential_IO;
with Ada.Text_IO;
with Interfaces;
---
--
procedure Create_LED is
type Byte is new Interfaces.Unsigned_8;
type Address is new Interfaces.Unsigned_16;
-- One of the cool feature of Ada is it's ability to set the lower and upper bound of an array to any value
-- you want. So we can set use the actual ROM addresses as array index an save ourself the work and remove
-- one potential error source.
--
type ROM_Type is
array (Address range 16#8000# .. 16#FFFF#)
of Byte;
package ROM_IO is new Ada.Sequential_IO (ROM_Type);
ROM_Output : ROM_IO.File_Type;
-- 65C02 related constants as named in the original WDC design document
--
NOP : constant Byte := 16#EA#;
NMIB : constant Address := 16#FFFA#;
RESB : constant Address := 16#FFFC#;
IRQB : constant Address := 16#FFFE#;
-- Another interesting feature Ada arrays is specifying the index of elements when initialising the array. As well
-- specifying an value for all not explicitly initialised values. Makes setting up the ROM array super easy.
--
ROM : constant ROM_Type :=
[16#8000# => 16#A9#, -- LDA #$FF
16#8001# => 16#FF#,
16#8002# => 16#8D#, -- STA $7F02
16#8003# => 16#02#,
16#8004# => 16#7F#,
16#8005# => 16#A9#, -- LDA #$55
16#8006# => 16#55#,
16#8007# => 16#8D#, -- STA $7F00
16#8008# => 16#00#,
16#8009# => 16#7F#,
16#800A# => 16#A9#, -- LDA #$AA
16#800B# => 16#AA#,
16#800C# => 16#8D#, -- STA $7F00
16#800D# => 16#00#,
16#800E# => 16#7F#,
16#800F# => 16#4C#, -- JMP $8005
16#8010# => 16#05#,
16#8011# => 16#80#,
NMIB + 0 => 16#00#, -- .word $8000
NMIB + 1 => 16#80#,
RESB + 0 => 16#00#, -- .word $8000
RESB + 1 => 16#80#,
IRQB + 0 => 16#00#, -- .word $8000
IRQB + 1 => 16#80#,
others => NOP];
File_Name : constant String :=
(if Ada.Command_Line.Argument_Count < 1 then "create_led.rom" else Ada.Command_Line.Argument (1));
begin
-- Just like Python Ada can write the whole array in one go.
--
ROM_IO.Create (ROM_Output, ROM_IO.Out_File, File_Name);
ROM_IO.Write (ROM_Output, ROM);
ROM_IO.Close (ROM_Output);
exception
when Error : Ada.IO_Exceptions.Name_Error =>
Ada.Text_IO.Put_Line ("File """ & File_Name & """ couldn't be created.");
Ada.Text_IO.Put_Line (Ada.Exceptions.Exception_Information (Error));
when Error : others =>
Ada.Text_IO.Put_Line ("File """ & File_Name & """ couldn't be written.");
Ada.Text_IO.Put_Line (Ada.Exceptions.Exception_Information (Error));
end Create_LED;
---------------------------------------------------------------- {{{ ----------
--: vim: set textwidth=0 nowrap tabstop=8 shiftwidth=3 softtabstop=3 expandtab :
--: vim: set filetype=ada fileencoding=utf-8 fileformat=unix foldmethod=marker :
--: vim: set spell spelllang=en_gb :
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