X-MEM, a new memory expansion for all CPC.

[Ast]

nothing obvious. both using asic pri.

both using expansion ram normally.

@Ast: Did you try x-mem and 464Plus?

I wonder if there is a conflict between ram on x-mem and internal 6128plus extra ram.

@gerald: I think it's a coincidence that demo doesn't work on arnold wip. It's using split screen and scroll quite heavily.

Sorry, no 464 plus.

[Ast]

I still have an unmodified 464plus. Will try this tonight.

Please tell us if it's running or not when your tests were done.

[CraigsBar]

I am at a fire station open day with the little fella at the moment. Will test when I get home later.

[arnoldemu]

How do I set a I/O breakpoint 

Open the debugger window. In the bottom right is the stack and the breakpoint windows.

(see attached picture)

Right click to bring up the menu.

Add Breakpoint->IO Breakpoint...

You will see the io breakpoint window. (see attached picture)

Here I have chosen a default and it has filled in all the details for me.

You can enter your own details here, port, port mask, data, data mask to allow capturing of any i/o read/write from any port with any specific data.

The default will capture any write to 7fxx with data bits 7,6 set. The debugger will stop *after* the instruction, so in the dissassembly window move up to see it.

In the debugger window in the top right is the hardware details panel. Z80 should be visible by default. I/O port and I/O Data tell you what the z80 saw.

[arnoldemu]

If it works on 464 with x-mem, then it's probably x-mem ram clashing with extra 64kb ram inside 6128 plus.

If it is still broken, then the only thing I can think of is that somehow the data bus is clashing so that the value written to the asic registers is a combination of the data in the x-mem ram and the value you write giving wrong results.

The last could be tested by keeping the ram active, writing various values into it, paging in the asic registers to setup a pri interrupt and see if it doesn't trigger correctly.

[Ast]

If it works on 464 with x-mem, then it's probably x-mem ram clashing with extra 64kb ram inside 6128 plus.

If it is still broken, then the only thing I can think of is that somehow the data bus is clashing so that the value written to the asic registers is a combination of the data in the x-mem ram and the value you write giving wrong results.

The last could be tested by keeping the ram active, writing various values into it, paging in the asic registers to setup a pri interrupt and see if it doesn't trigger correctly.

So what others non amstrad plus proggy works correctly?


Edit:

I think for example asm program Orgams which works correctly on amstrad plus with 512kb x-mem ram?
I believe the problem is another thing.

[arnoldemu]

So what others non amstrad plus proggy works correctly?

do cartridge games work with it?

and do the normal cpc games such as chase hq or robocop work with it and the plus?

[Ast]

I also answered in my edit 

[arnoldemu]

I also answered in my edit 

it seems like a clash between asic ram and the expansion ram..

If I write a test program to test this theory please would you run it?

[Ast]

Of courso, i'll do.


Edit:
I've just made some test with my c4cpc+x mem and there is no problem.

[TFM]

You can use the FutureOS System monitor (Plus version) to check if RAM or Memory-Mapped is banked it. RAM/ROM/MM can be selected individually. No need to invent the wheel again. 

[arnoldemu]

You can use the FutureOS System monitor (Plus version) to check if RAM or Memory-Mapped is banked it. RAM/ROM/MM can be selected individually. No need to invent the wheel again. 

My test will be different

[TFM]

My test will be different

Yes, but if it fails in that (check banking in system monitor), why do bother wasting time?

[arnoldemu]

Yes, but if it fails in that (check banking in system monitor), why do bother wasting time?

good point.

[Ast]

Something strange, the "revival'n impact cooperation" demo seemes to work using the firmware 3.1 of x-mem, but sound and sprites hard are so buggies...
Sound use only dma to be played... It's really strange.

[Ast]

I think problem must be between asic page connection and xmem mapping connection...

[gerald]

Open the debugger window. In the bottom right is the stack and the breakpoint windows.

(see attached picture)

Fount it, thanks to your screenshot. The stack/breakpoint pannel had a zero vertical size !

[arnoldemu]

@Ast: I agree please try the attached dsk and tell me what you see.
if all is good there will be a stable pri interrupt.

no pri = ram probably takes priority.
stable pri = asic ram takes priority
unstable pri = data potentially mixing.

[arnoldemu]

Fount it, thanks to your screenshot. The stack/breakpoint pannel had a zero vertical size !

Hmmm.. I will reset my settings and see if I can fix it. If not I will report the fault to wxwidgets.

[gerald]

I think problem must be between asic page connection and xmem mapping connection...

At least it is not xmem only related, my own interface has the same problem.
@CraigsBar, can you test with your symbiface ?

[Ast]

@Ast: I agree please try the attached dsk and tell me what you see.
if all is good there will be a stable pri interrupt.

no pri = ram probably takes priority.
stable pri = asic ram takes priority
unstable pri = data potentially mixing.

I'm going to test it and came back to tell you the result.

[Ast]

And the result is :


Stable PRI Black 2/3 and Cyan 1/3

[Ast]

It seems to be all right so what to do?   

[arnoldemu]

And the result is :


Stable PRI Black 2/3 and Cyan 1/3

ok. That is correct, so no problem with that test.

The test did the following:
- page in 7fc4 and keep it active.
- wait for vsync, set to black
- write a number to 6800 in ram. (1-255)
- page in asic ram (leave it active), write 128 to pri
- wait for pri
- set cyan
- repeat

Ram expansion did not cause problems with this test.

I will think of some other tests.

[gerald]

It seems to be all right so what to do? 

Small question, is your demo code reading from the ASIC ram while extension RAM is also selected ?