Dragon 32/64 - Revision history

ToBach at 13:45, 13 April 2024

2024-04-13T13:45:00Z

ToBach: /* Sync with frame */

2024-04-13T13:33:10Z

‎Sync with frame

ToBach: /* Sync with frame */

2024-04-13T13:31:26Z

‎Sync with frame

ToBach: /* Sync with frame */

2024-04-13T13:30:40Z

‎Sync with frame

Superogue at 07:03, 13 April 2024

2024-04-13T07:03:17Z

Superogue at 06:55, 13 April 2024

2024-04-13T06:55:42Z

Superogue: Created page with "== Dragon32 / Dragon64 == The Dragon 32 and Dragon 64 are home computers that were built in the 1980s. The Dragons are very similar to the TRS-80 Color Computer, and were prod..."

2024-04-13T06:50:37Z

Created page with "== Dragon32 / Dragon64 == The Dragon 32 and Dragon 64 are home computers that were built in the 1980s. The Dragons are very similar to the TRS-80 Color Computer, and were prod..."

New page

== Dragon32 / Dragon64 ==
The Dragon 32 and Dragon 64 are home computers that were built in the 1980s. The Dragons are very similar to the TRS-80 Color Computer, and were produced for the European market by Dragon Data, Ltd., initially in Swansea, Wales before moving to Port Talbot, Wales (until 1984) and by Eurohard S.A. in Casar de Cáceres, Spain (from 1984 to 1987), and for the US market by Tano Corporation of New Orleans, Louisiana. The model numbers reflect the primary difference between the two machines, which have 32 and 64 kilobytes of RAM, respectively.

=== Setting up ===
To set up your , first get the following tools:

* Assembler: asm6809 ( https://www.6809.org.uk/asm6809/ )
* Emulator(s): xroar ( https://www.6809.org.uk/xroar/ )

=== Memory map ===

<syntaxhighlight lang="6809">
</syntaxhighlight>

Check out - for a complete memory map

=== Video display ===
The Dragon 32 / Dragon 64 have the following native video modes:
* Standard text modes
* Bitmap modes

==== Sync with frame ====
<syntaxhighlight lang="6502">
-
</syntaxhighlight>

==== Plot in Bitmap modes ====
Here is a routine that will allow you to plot a single point in bitmap mode.
<syntaxhighlight lang="6502">
To be added
</syntaxhighlight>

==== Text mode ====
To be added
<syntaxhighlight lang="6502">
To be added
</syntaxhighlight>

=== Sound ===
To be added soon.

==== Make some noise ====
To be added soon.

=== Additional Resources ===
* World of Dragon forums - https://archive.worldofdragon.org/phpBB3/
* 6809.org.uk Website - https://www.6809.org.uk/

@@ Line 43: / Line 43: @@
 Syncing with VSYNC can be done in a few ways, the most common being:
 <syntaxhighlight lang="6502">
-vskip
+wait_for_vsync
      lda $ff03   ;polling vsync
-     bpl vskip
+     bpl wait_for_vsync
      lda $ff02   ;acknowledge vsync
      ;rest of your code...

@@ Line 50: / Line 50: @@
 </syntaxhighlight>
-However if you really want to save the bytes, it can be done with just one instruction. However it will not only wait for VSYNC but also other system interrupts that may be going on, so don't expect 100% reliability.
+If you really want to save the bytes, it can be done with just one instruction. However it will not only wait for VSYNC but also other system interrupts that may be going on, so don't expect 100% reliability. It will also do the acknowledgement for you.
 <syntaxhighlight lang="6502">
      sync

@@ Line 36: / Line 36: @@
 === Video display ===
-The Dragon 32 / Dragon 64 have the following native video modes:
+The Dragon uses the Motorola 6847 VDG, it has the following native video modes:
-* Standard text modes
+{| class="wikitable"
-* Bitmap modes
+|-
 ==== Sync with frame  ====

@@ Line 11: / Line 11: @@
 <syntaxhighlight lang="6809">
 </syntaxhighlight>
-Check out - for a complete memory map
+Check out http://dragon32.info/info/memmap.html for a complete memory map
 === Video display ===

@@ Line 44: / Line 44: @@
 === Additional Resources ===
 * World of Dragon forums - https://archive.worldofdragon.org/phpBB3/
 * 6809.org.uk Website - https://www.6809.org.uk/