AMSDAP - Amstrad MSx aDAPter - connecting any MSX I/O hardware to the CPC

[Mork]

So it looks like that Tecnobytes uses a deviant design with their TRH9000 that causes a blocked keyboard using a CPC6128.
Using a CPC6128 Plus I don´t have the problem, so what is the difference between these 2 devices concerning the expansion port and the keyboard ?

[dodogildo]

So it looks like that Tecnobytes uses a deviant design with their TRH9000 that causes a blocked keyboard using a CPC6128.
Using a CPC6128 Plus I don´t have the problem, so what is the difference between these 2 devices concerning the expansion port and the keyboard ?

TRH9000 is made by The Retro Hacker not by Tecnobytes.
And, not only the keyboard but also the CPC itself freezes.

[poulette73]

TRH9000 is made by The Retro Hacker not by Tecnobytes.
And, not only the keyboard but also the CPC itself freezes.

Ok ok, sorry I misunderstood.
Sorry for my off-topic with Tecnobytes.  

[Mork]

Ok, but my CPC don´t freezes completely.
I was able to run a V9990-Basic-program via autoexec.bas from the M4-Board and I see the correct result on the TRH9000-Monitor.
So the CPC works, only the keyboard is blocked.

[dodogildo]

@Mork can you share the program and describe what you did, pls. I'm gonna try it when I have the chance.

[Mork]

I initialized screen B3 in BP6-mode, defined some colors, set the border to black and drew a blue painted rectangle.
All via Basic-Out-commands.
How can I place pictures here?

[HAL6128]

You can also try my adaption of a MSX V9990 demo for the CPC? P1 mode with sprites and background.
https://www.cpcwiki.eu/forum/index.php?msg=241884

[XeNoMoRPH]

You can also try my adaption of a MSX V9990 demo for the CPC? P1 mode with sprites and background.
https://www.cpcwiki.eu/forum/index.php?msg=241884

I didn't know this demo, fantastic!!!

[dodogildo]

You can also try my adaption of a MSX V9990 demo for the CPC? P1 mode with sprites and background.
https://www.cpcwiki.eu/forum/index.php?msg=241884

How can I launch this automatically (via M4 for instance) once the CPC is turned on? 
Because my CPC gets unresponsive with Amsdap+TRH9000 connected and I can't run any tests manually..

[HAL6128]

You can create an autoexec.bas file to run the file "0.bas" without any keyboard input. Just look into the M4info.txt documentation on Dukes website.

[Prodatron]

I'm wondering what the Amsdap might disturb in the CPC. The keyboard is connected to the Soundchip and the PPI 8255 IO.

Indeed, how is it possible, that the expansion bus is blocking the keyboard? Can it disturb the PPI?
Is sound still working?

Seems that the TRH9000 is a version of the V9990 MSX card, which has something different compared to the previous ones.

[gflorez]

My humble assumption is that the cartridge is not doing correctly the ports decoding. I will try to talk with the creator.

[Prodatron]

My humble assumption is that the cartridge is not doing correctly the ports decoding. I will try to talk with the creator.

Thanks!
With Amsdap only the range between #ff00 and #ffff should be decoded, no matter what the MSX cards are really doing. From my understanding that should make it impossible to disturb the PPI or so. But I am not a hardware guy.

[dodogildo]

TRH9000 is an open-source video card: https://github.com/cristianoag/trh9000

[retro space]

TRH9000 is an open-source video card: https://github.com/cristianoag/trh9000

How do you aquire the main chip?

[Mork]

theretrohacker.com also sells the chip only.

@Prodatron: sound works partly. I can play tunes via the sound-command but they don't stop after the given time. Only one tune per channel is possible, a second one is ignored while the first keeps on playing.

On the 6128 Plus everything works fine.

[gflorez]

 Translator
 
 
I have read the TRH9000 Kicad files and I have found it uses an alternative method to detect a port access with /IORQ and /M1,  instead of /IORQ, /RD and /WR, maybe to save some circuitry.    /M1 is a signal that marks when the Z80 is reading the next instruction from memory, but it is tricky because the Z80 uses /IORQ and /M1 both active to know when it is on interrupt status.

What I think is happening: The 74LS245 on the Amsdap(the same use on every MSX2) is a tristate buffer that controls when the cartridge is accessed, this is, every time a port is accessed(decoded), on read or write mode, the 74LS245 acts like an open window(/Busdir signal is active) , closing when there is no access.( /Busdir signal inactive)   I think that decoding ports with /M1 forces the 74LS245 to open on some unwanted moments, not importan on a MSX but probably tricky on a CPC. On the other side, the V9990 has its data bus floating, it can have any value on it when not in use. If the 74LS245 opens when the Z80 is accessing the data bus, the content can be corrupted with the V9990 data bus garbage, fooling the Z80.

I may be wrong in this, so I have asked some wise men.

[gflorez]

 Translator
 
 
About the Wozblaster Reloaded not detected, is it based on a real OPL4 placed on the same ports than the Moonsound?

It is probably working, but some information is needed on how access it.

[Mork]

Interesting!
Any idea why this doesn't seem to affect a CPC Plus model?

[gflorez]

I have just bought a TRH9000(OUCH!)... Now I can test the real hardware in my computers. Effectively, it works flawless on my 6128+, but I have no other CPC to test. On my Enterprise it doesn't work at all, I only can see some blinks on the screen when I run SymbOS.

What I have seen until now: For me it is still a problem on the ports decodification. Cristiano has used HC series chips on the port decodification stage, while the recommended series for these computers is LS or HCT, that work on TTL level (+5v). It seems this causes no problem on a 90s computer, but impedes the communication with middle 80s computers.

What I will do next is to exchange the two HC series chips involved with the correspondent 74LS32 and 74LS138, and then do more tests. I own a GFX-NINE, other V9998 clone that has the same logic with HCT series chips and works perfectly on my Enterprise.

[Prodatron]

Something is really strange with the last TRH9000 version...
Gustavo, thanks a lot for examining it!

[dodogildo]

Something is really strange with the last TRH9000 version...

The old TRH9000 version has similar problems with Amsdap.

[gflorez]

I have already tested the TRH9000 with two LS series chips.... and it works on my Enterprise!

So,  the solution could be "very easy": exchange these HC chips with the HCT or LS compatible series and it will work. The chips are on the back side of the PCB, marked as U1(74HC138) and U2(74HC32).

It is very annoying for me not be able to put a direct picture file here of what I have done and the results, sorry.

It only rest me to make the final test, trying the cartridge on a classic CPC. I will borrow one from a friend.

[eto]

It is very annoying for me not be able to put a direct picture file here of what I have done and the results, sorry.

because you don't have taken a picture or because the "quick reply" doesn't offer a way to attach pictures? If it's the latter, two options to solve it: 
1) in quick reply click "preview" - then there is a drop-zone to add attachments and pictures
2) instead of a quick reply use the "Reply" button - which opens the full editor including dropzone. 

[dodogildo]

I have already tested the TRH9000 with two LS series chips.... and it works on my Enterprise!

And does it still works with the MSX?