OCM-PLD Pack v3.2 by KdL released

Nope, off-coarse you're not the last dreamer in the MSX world
Great going you FPGA designer, you did it again. Will definitively update my OCM with the new version when i'm using it the next time !

..uoops! no no no, only the sexy women may call me ''hacker''.
Wikipidia have not a complete and updated idea of the hacker term. I'm NOT a hacker definately!

With the next OCM-PLD v3.3 will come a better VDP and a bit improved VGA upscaler.

Thanks to you mi OCM is a great machine. The factory configuration for OCM is simply a mess.

a parallel beta version has showed me a perfect resolution by 640x480 @60Hz on wide lcd screen
with a perfect pixel ratio with NTSC mode (not with PAL mode for the moment)

Thanks very much ^_^. I'll test it soon in my Zemmix Neo

Hi KdL, I just installed it on my OCM (my first ever update ) and it works well!

I have one bug report though, the ESE-SCC doesn’t reset the phase of the wave that is played when the frequency is changed, which the original SCC does do. This was already the case with the original OCM firmware.

You can test this by playing a note on channel 1 (e.g. C3 saw wave), and then binding a key to play the same note on channel 2 while it’s pressed (set the frequency each time). On a real SCC or SCC-I, if you press the key, it sounds a little different every time because the phases of the two notes aren’t aligned. If you only set the frequency once and just toggle the volume, you’ll notice it always sounds the same.

I guess it can be argued which behaviour is better musically, personally I think it would’ve been better if the phase reset was tied to the volume going from 0 to nonzero. But if correct emulation of the SCC is the goal, it should reset the phase when the frequency LSB or MSB is written.

Added at todo list! I will check it as soon as possible. Many thanks!!!

Looks like an epic update! Is it possible to flash my original OCM with it?

That Zemmix Neo looks sexy! I want one .

Another great update.. one tip, could you not use 7z as format.. nobody uses that .

Hi msd. The 2MB RAM is more compatible than 4MB on games.
The 7z is the best free zipper. I suggest HaoZip_v4.0.1.9380 ru-board edition for Windows, not all!

You should try Bandizip : http://www.bandisoft.com/bandizip/en/

Even PMA files can be unzipped !

@KDL: Did you ever try the opl4 and v9990 at the same time in the ocm. It can't read the registers of the v9990 if both attached. Opl4 and v9990 severalty connected works fine. (I didn't try with your latest update yet), however both in a slotexander connected to the ocm does work.

2014.06.05 OCM-PLD v3.2.1 for 1chipMSX and Zemmix Neo is out!

none diff... added a precompiled Zemmix Neo firmware!

I went back to 3.2... My keyboard layout became a bit weird...

@mars2000you: thank you for suggestion on Bandizip, it's not bad!

@KDL, the latest fix also doesn't help. There is something strange with interrupts from cartridges.

I think I now understand what is happening. In mbwave the vdp interrupt is also so running. So atleast 60 times per second it is checked if the intterupt came from the opl4 or the vdp. In many interrupts from the vdp the opl4 will have it's status set that the interrupt is active. The music never goes faster when I increase the opl4 interrupt speed because it is not checked faster. When I go slower than 60Hz it does go a little slower because the opl4 will not have set the interrupt active status bit. So my conclusion is that the interrupt line from cartridge slots is not handled at all anymore. Probably broken in the update 3.2 of the ocm.

@Grauw: you also running the ocm with this version?

Hi all.
Unfortunately the bug of interrupt is familiar to me from the previous version of TH9958 that broke the Music Module MIDI part.
I hope to have time to rewrite this module for the next months.

For now you can try with MSX2 firmware of OCM-PLD PACK v3.2

@Grauw:

1st test:
Try turning off the lights (press the PAUSE on keyboard) and reply if this is a interference of red LEDs.

2nd test:
Try the STEREO mode of SMART COMMANDS and reply me with the results (solved or not).

The white channel is mixed to external sound cartridges while the red is internal audio only:
there are cartridges connected to the ext slots ?

yep I know HRA had introduced this bug with his VDP TH9958 but the changes were too many in a short time and a diff comparison of V9938 was not possible for me in past

yes on history.txt is reported the Music Module MIDI bug for MSX2+ firmware:

- MIDI-IN of Music Module do not work properly with VDP TH9958.

I'm looking forward to that update

have you tried with the original firmware of ocm or another one?

can you recording the hum from red line?

Correction: the hum is on both lines. The preamplification for the left channel on my mixer was accidentally set lower.

When I play an external SCC on the white channel, I can also hear it softly on the red channel if I turn down the volume of the white one.

Maybe it’s just unavoidable interference from the hardware, and it’s not horrible (like the Zemmix Neo’s high pitched beep on its original firmware which you so nicely fixed ;p), and I’m pretty sure my old Philips NMS8245 also does some humming… But at default PSG volume in Basic (V8?) it is definitely audible when nothing’s playing… So it would be nice if something could be done about it.

Ok, thanks . Would it be possible for the OCM to have a balanced output? That would fit better in my analog mixing set-up :).

The basic idea of balanced audio output is that there’s a third output line which contains the exact inverse of the audio line. The mixer / amplifier then uses this to cancel out the noise. Think it should be possible by outputting the balanced line on the second plug, and then make an adaptor cable from two RCA to one balanced three-pin XLR or TRS plug.

http://en.wikipedia.org/wiki/Balanced_audio

Also see this article and this article.

@KDL: Do you know something about a fix in the status register. Something that does work with the v9958 firmware but not with the v9938. I've a program that fails on checking some status registers.

@KdL Very cool!

I will test it but I need to make a custom cable first, will take me a bit of time (don’t have the components).

@KDL: I am investigating some potential bug of the ese v99x8 vdp. When you read status register 0 the Vertical scan interrupt flag is reset, but other bits of this status register is also reset, this should not happen.

in a,(99)
; result = 0x86
in a,(99)
; Result = 0x0 and should be 0x06

Sweet!

Does this also fix the interrupts from Music Module MIDI?

p.s. I should receive parts to make a balanced cable for testing tomorrow.

@Grauw: I think yes, tested by msd.
The Midi part of my Music Module is broken and it's not possible for me to test it. sob! sob!!

A new package is here for you: PLD 3.2.2 Right Inverse ** TEST **

yep, you are damn right! Also I will fix it

@KdL It works marvellously!

When I play some PSG notes, I hear them very clearly and nary a hum to be heard. Whereas if I use a normal mono connection, the hum returns. (And when I mix both channels in mono, as I increase the volume they cancel each other out and only the hum remains . Kind of the opposite effect hehe.)

However when I plug in the SCC the hum appears on the balanced connection, and when I play it it sounds distorted. I guess you didn’t invert the signal for the external cartridge output and it’s still using the old signal path?

Well, I guess that won’t work; looking at the OCM schematics and board, the RCA ring is hard-wired to the ground and not through the FPGA. Too bad.

Advantage of the current solution is that one can buy a simple stock 2x RCA to ¼" stereo TRS lead (e.g. 1 or 2) and plug it into a balanced mixer input… It won’t be perfect cause the signal wires aren’t twisted, which prevents external magnetic field interference, but it’s still shielded and the biggest problem is internal interference anyway.

Using those cables, the hot signal of a balanced audio jack is carried on the tip of the TRS connector, which is connected to the left channel (white), so probably best to put the inverted signal on the right channel (red), so that people won’t connect it the wrong way.

yes, unfortunately it is so!
would you like a new smart command or I leave a "rem" line inside the source code simply?

Another idea for a smart command: given that most of the interference on the audio seems to be generated by the video circuitry (right?), commands to switch video output off and on again.

In Synthesix I plan to have a “recording mode” which disables the UI and processes the MIDI events on the main loop to minimise latency. This mode could then also provide an option to disable the video output if it’s running on an OCM.

(On other MSX computers, I guess I’ll see if black screen in blanking mode reduces the interference.)

ouch!! a blind MSX !!

Any idea when the "official" 3.3 version will be released for the OCM and Zemmix Neo?

Good to hear! As it was an RC I didn't want to put it on my Zemmix Neo. Keep up the good work!

I think I found the origin of the behaviour, posted about it here.

Hi Grauw, with the next OCM-PLD v3.4 you will benefit from this feature.

-------------------------------------------------------------------------------
      Smart Commands Table  Revision 005  by KdL 2011-2017     Page 5 of 8
-------------------------------------------------------------------------------
      ...
35 -> Lock   Hard Reset Key
36 -> Unlock Hard Reset Key
37 -> Lock   Mapper Toggle
38 -> Unlock Mapper Toggle
39 -> Lock   MegaSD Toggle
3A -> Unlock MegaSD Toggle
3B -> Lock   All Toggles
3C -> Unlock All Toggles (default)
3D -> Set Pseudo-Stereo OFF (default)
3E -> Set Pseudo-Stereo ON (external sound cartridge required)
3F -> Sync External Bus Clock to CPU Speed (default)
40 -> Set External Bus Clock 3.58MHz
41 -> Set Turbo Pana 5.37MHz
42 -> Set Right Inverse Audio OFF (default)
43 -> Set Right Inverse Audio ON
80 -> Null Command (useful for programming)

-------------------------------------------------------------------------------