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boards:ecb:scg:start [2018/08/10 04:35]
b1ackmai1er [MSX Programs]
boards:ecb:scg:start [2018/12/16 02:25] (current)
trick-1 [Parts List]
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 {{:​boards:​ecb:​scg:​scg-002-bom.xlsx|Parts List - XLS}} {{:​boards:​ecb:​scg:​scg-002-bom.xlsx|Parts List - XLS}}
  
-The TMS9918 is an NTSC format chip. A PAL version of this chip is available (TMS9928A) but it is not known if it is compatible.+The TMS9918 is an NTSC format chip. A PAL version of this chip is available (TMS9928A) but it is not totally compatible per the following from the datasheet. 
 + 
 +"The TMS9928A/​9929A VDP's are functionally identical to the TMS9918A except that the NTSC color encoding circuitry has been removed and replaced with luminance and color difference signals. The TMS9918A ​is pin-for pin compatible ​with the TMS9928A/​9929A,​ except for three pins, the composite vide output, the external video input and the CPU clock output. These pins are replaced with the Black,White luminance and composite sync (Y) output and two color difference pins, Blue (B-Y), and Red (R-Y) outputs, respectively. The color difference outputs allow the user to generate Red-Green-Blue (R-G-B) drive for direct color gun control, or composite video for use with NTSC or PAL video color monitor. However, to connect these three outputs to R-G-B or monitor requires additional R-G-B or encoder circuity"​ 
 + 
 +So maybe that is something for the next iteration...
  
 A 2Mhz crystal is specified for the sound chip clock but on board dividers can be configured to use a higher frequency crystal. Also common serial and colour burst frequency crystals can be used depending on your need for frequency accuracy and compatibility. A 2Mhz crystal is specified for the sound chip clock but on board dividers can be configured to use a higher frequency crystal. Also common serial and colour burst frequency crystals can be used depending on your need for frequency accuracy and compatibility.
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 </​code>​ </​code>​
  
-The sound chip drives a total of three audio channels (A-C). ​ The center channel (B) is hard-wired to mix it's output into channels A & C (left & right). ​ If you want to bridge all three channels to produce monophonic output, you can short pins 1-2 and/or 3-4.+The sound chip drives a total of three audio channels (A-C). The center channel (B) is hard-wired to mix it's output into channels A & C (left & right). If you want to bridge all three channels to produce monophonic output, you can short pins 1-2 and/or 3-4.
  
 <​code>​ <​code>​
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 **RV9: Right Channel Audio Output Volume** **RV9: Right Channel Audio Output Volume**
 +
 +<​note>​The left channel and right channel trimpot'​s are wired in reverse direction and will need to be set at different positions for equal sound levels on each channel.</​note>​
  
  
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 The SCG board is not intended to be a general purpose terminal controller like the VDU, CVDU, and VGA3 boards. It does not have a keyboard interface and text output is limited to 40 characters per row. So, the typical way to use the board would be to add it to an existing system already running CP/M (RomWBW, UNA, etc.) and then run programs that utilize the graphics and sounds capabilities of the board. The MSX games and programs described below do exactly this. You start your system in normal CP/M, then run the MSX game/​program desired. The SCG board is not intended to be a general purpose terminal controller like the VDU, CVDU, and VGA3 boards. It does not have a keyboard interface and text output is limited to 40 characters per row. So, the typical way to use the board would be to add it to an existing system already running CP/M (RomWBW, UNA, etc.) and then run programs that utilize the graphics and sounds capabilities of the board. The MSX games and programs described below do exactly this. You start your system in normal CP/M, then run the MSX game/​program desired.
  
-Note that RomWBW (v2.8.5 ​and abovedoes provide ​support for text output to this board (assuming you have enabled ​TMS support). The board is accessed as the CRT device, so sending output to CRT: will work. However, it is not possible to read from the CRT: device because the board has no text input capability. It is **not** ​ necessary to have the TMS driver enabled in RomWBW to launch the MSX software – the MSX emulator below includes it's own driver for the board.+RomWBW (v2.8.5+provides ​support for text output to this board when TMS support ​is enabled. The board is accessed as the CRT device, so sending output to CRT: will work. 
 + 
 +<​code>​ 
 +B>PIP CRT:​=A:​TEXTFILE.TXT 
 +</​code>​ 
 + 
 +It is not possible to read from the CRT: device because the board has no text input capability. It is **not** necessary to have the TMS driver enabled in RomWBW to launch the MSX software – the MSX emulator below includes it's own driver for the board. 
 + 
 + 
 +==== Test Software ==== 
 + 
 +Two programs are available to test basic video operation of the card in the {{:​boards:​ecb:​scg:​tms9918-test.zip|tms9918-test}} ​ package. Refer to images below. 
 + 
 +HW9918.COM will display the "HELLO WORLD" text on the screen. 
 + 
 +TSTSPR.COM will display sprites and allow background colour changes. 
 + 
 +Sound functionality can be tested with the {{:​boards:​ecb:​scg:​ay-test.zip|ay-test}} ​ package. 
 + 
 +AY-TEST.COM will output a descending tone to each sound channel. 
  
 ==== MSX Programs ==== ==== MSX Programs ====
boards/ecb/scg/start.1533890139.txt.gz · Last modified: 2018/08/10 04:35 by b1ackmai1er
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