YM2151 Programming - Revision history

MSaarna at 13:39, 28 February 2020

2020-02-28T13:39:29Z

2020-02-28T13:39:04Z

‎Mapping the XM YM2151 into address space

2020-02-25T21:53:34Z

2020-02-25T21:51:52Z

2020-02-25T21:48:05Z

2020-02-25T21:30:38Z

2020-02-25T21:28:25Z

2020-02-25T21:26:43Z

2020-02-25T21:06:25Z

2020-02-25T21:01:18Z

← Older revision		Revision as of 13:39, 28 February 2020
Line 9:		Line 9:

	Once the YM2151 is mapped in, it is ready and active at addresses $460 and $461.		Once the YM2151 is mapped in, it is ready and active at addresses $460 and $461.
		+

	== Updating Registers on the YM2151 ==		== Updating Registers on the YM2151 ==

@@ Line 6: / Line 6: @@
 == Mapping the XM YM2151 into address space ==
-The XM Ctrl register is used to map devices in and out of address space. Writing the value #$84 will will make the YM2151 and cartridge ROM available. If you want other hardware present, like the pokey sound chip, you'll need to modify the value appropriately. (see the official [http://www.7800xm.com/XMdevelopers.htm XM developer docs])
+The XM Cntrl1 register ($470) is used to map devices in and out of address space. Writing the value #$84 to this location will make the YM2151 and cartridge ROM available. If you want other hardware present, like the pokey sound chip, you'll need to modify the value you write appropriately. (see the official [http://www.7800xm.com/XMdevelopers.htm XM developer docs])
 == Updating Registers on the YM2151 ==

@@ Line 126: / Line 126: @@
   |}
 == Miscellaneous Application Notes ==
 * Avoid issuing a note-off too soon after a note-on, as this will cause a lot of distortion in the sound. One way around this is to reverse the usual order, and issue a note-off on your channel prior to the note-on.

← Older revision		Revision as of 21:51, 25 February 2020
Line 126:		Line 126:

	\|}		\|}
		+
		+	== Miscellaneous Application Notes ==
		+
		+	* Avoid issuing a note-off too soon after a note-on, as this will cause a lot of distortion in the sound. One way around this is to reverse the usual order, and issue a note-off on your channel prior to the note-on.

@@ Line 19: / Line 19: @@
      bmi WaitForYMReady
-To update the YM registers, you write the YM register location to the $460 location, and then the value you wish to write to the YM register to $461. For convenience, the following subroutine will write the A register contents to the X register location.
+To update the YM registers, you write the YM register location to the $460 location, and then the value you wish to write to the YM register to $461. For convenience, the following subroutine will write the A register contents to the X register location, with all of the necessary waiting.
   YM2151BASE = $460

@@ Line 43: / Line 43: @@
   {|
    |+YM2151 Registers
-   ! Location &nbsp; &nbsp; &nbsp; &nbsp;  &nbsp; &nbsp;
+   ! Location
-   ! Bits Used &nbsp; &nbsp; &nbsp; &nbsp;  &nbsp; &nbsp;
+   ! Bits Used
-   ! Register &nbsp; &nbsp; &nbsp; &nbsp;  &nbsp; &nbsp;
+   ! Registers
-   ! Register Description&nbsp; &nbsp; &nbsp; &nbsp;  &nbsp; &nbsp; &nbsp; &nbsp;  &nbsp; &nbsp;
+   ! Register Descriptions
-   ! Alt Reg Name &nbsp; &nbsp; &nbsp; &nbsp;  &nbsp; &nbsp;
+   ! Alt Register Names
-   ! Comment &nbsp; &nbsp; &nbsp; &nbsp;  &nbsp; &nbsp;
+   ! Comment
    |-
    | 01 || <tt>%TTTTTTTT</tt> || TEST || Test || - || not used for XM

@@ Line 70: / Line 70: @@
    | 1B || <tt>%CC----WW</tt> ||CT,W || MHz, LFO Wave (Saw,Sqr,Tri,Noise) || - || Control (not used for XM?), change LFO Wave
    |-
-   | 20-27 || <tt>%RLFFFCCC</tt> || R-EN,L-EN,FL,CON || Enable Left/Right, Feedback lvl, Connection algorithm || R,L,FB,CONECT || Per channel/instrument setup
+   | 20-27 || <tt>%RLFFFCCC</tt> || R-EN,L-EN,FL,CON || Enable Left/Right, Feedback lvl, Connection algorithm || R,L,FB,CONECT || Per channel, operator connectivity
    |-
    | 28-2F || <tt>%-OOONNNN</tt> || OCT,NOTE || Octave, Note || KC || Per channel, octave and note to use when note-on is triggered

@@ Line 99: / Line 99: @@
    |-
    | 98-9F || <tt>%KK-AAAAA</tt> || KS,AR || Keyscale, Atack || - || Per channel, OP4
    |-
   |}

@@ Line 69: / Line 69: @@
    |-
    | 1B || <tt>%CC----WW</tt> ||CT,W || MHz, LFO Wave (Saw,Sqr,Tri,Noise) || - || Control (not used for XM?), change LFO Wave
    |-
    | 20-27 || <tt>%RLFFFCCC</tt> || R-EN,L-EN,FL,CON || Enable Left/Right, Feedback lvl, Connection algorithm || R,L,FB,CONECT || Per channel/instrument setup
@@ Line 76: / Line 75: @@
    |-
    | 30-37 || <tt>%KKKKKK--</tt> || KF || Key Fraction || - || Per channel, for pitch bend
    |-
-   | 40-47 || <tt>%-DDDMMMM </tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP1
+   | 40-47 || <tt>%-DDDMMMM</tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP1
    |-
-   | 48-4F || <tt>%-DDDMMMM </tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP3
+   | 48-4F || <tt>%-DDDMMMM</tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP3
    |-
-   | 50-57 || <tt>%-DDDMMMM </tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP2
+   | 50-57 || <tt>%-DDDMMMM</tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP2
    |-
-   | 58-5F || <tt>%-DDDMMMM </tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP4
+   | 58-5F || <tt>%-DDDMMMM</tt> || DT1,MUL || Detune1, Multiply || - || Per channel, OP4
    |-
   |}