For openMSX machine configurations (and general knowledge about machines) we need to be 100% sure if (or which of) the MSX2+ machines (or MSX2 machines with 64kB RAM) have a memory mapper or not...

So, if you happen to own an original, unmodified MSX2 or MSX2+ with 64kB of main RAM, please do the following test for us:

1) start the machine to basic (without any device in the cartridge slots)
2) type a simple line in basic like this: 10 PRINT "HELLO"
3) type: OUT &HFE,2
4) type LIST
and please check what the result is (and remember this). It either shows nothing (then it has a mapper) or shows the just entered program (then it has no mapper).
Now we doublecheck:
5) type OUT &HFE,1
6) type LIST
Now the program should be back in case it disappeared.

Please e-mail me with the results: machine brand name and type (e.g.: Panasonic FS-A1WX) and the results of the test.

Thanks in advance!

(PS: yes, this text was bluntly reused from an MSX Mailinglist e-mail! But we still don't have enough reactions...!)

According to the technical handbook, MSX2 should have a memory mapper, even the machines with just 64KB ram. Probably the same thing applies for MSX2+

Quote:

According to the technical handbook, MSX2 should have a memory mapper, even the machines with just 64KB ram. Probably the same thing applies for MSX2+

This is not true! MSX2 should not have a memory mapper. It should have at least 64kB RAM, but not a mapper. An example is the Sony HB-G900P, an MSX2 with 64kB plain RAM.

It could be that the MSX2+ spec says that it needs to have at least 64kB mapper. But I want to have evidence of that, before I believe it, although I think this is quite likely.

Manuel, this is what I took from the MSX2 Technical Handbook (text version by Nestor):
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font class="mrc-small">Code:</font><HR></TD></TR><TR><TD><FONT class="mrc-small"><PRE>

------------
| CPU Z80A |
------------
|
| ----- -------------------------------
+--| |--| ROM 48K (MSX-BASIC ver 2.0) |
| | | -------------------------------
| | S | ----------------
| | |--| MAIN RAM 64K |
| | L | ----------------
| | | ::::::::::::::::: :::::::::::::::::
| | O |::: MEMORY MAPPER :::: RAM 64K to 4M :
| | | ::::::::::::::::: :::::::::::::::::
| | T | :::::::::::::
| | |::: CARTRIDGE : I/O Cartridge (Disk, RS-232C)
| | | ::::::::::::: RAM Cartridge
| ----- ROM Cartridge (Game, Application)
| Slot Expansion Box, Etc.
| blablabla...
</PRE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>

See? A memory mapper!

Arjan is right. I remember at least once reading somewhere (I believe in MCM) that even if an MSX2 or MSX2+ had only 64kB RAM, this RAM was still located in a memory mapper. The exact amount of memory is not relevant. In fact, the memory mapper was one of the innovations of the MSX2 standard.

Quote:

| | | ::::::::::::::::: ::::::::::::::::: | | O |::: MEMORY MAPPER :::: RAM 64K to 4M : | | | ::::::::::::::::: ::::::::::::::::: See? A memory mapper!

See, an OPTIONAL memory mapper! Read the text below the picture
"Note: The dotted lines represent optional features."

The ::::::::::-lines are optional, the ----------- are not.

Quote:

Arjan is right. I remember at least once reading somewhere (I believe in MCM) that even if an MSX2 or MSX2+ had only 64kB RAM, this RAM was still located in a memory mapper. The exact amount of memory is not relevant. In fact, the memory mapper was one of the innovations of the MSX2 standard.

MCM is not correct in everything. The Sony HB-G900P really doesn't have a memory mapper. Also many Japanese MSX2 machines don't have one.

By the way, see also www.msxnet.org/gtinter/mapper.htm

Well what was that song from a Bond movie

And nobody does it better .... makes it feel sad for the rest

well my MSX doesn't have 64kb non-mapped memory
but otherwise, the manual doesn't mention anything about memory mappers (or I couldn't find it..). strange indeed...

The MSX2+ standard defines a memory mapper. It is no longer optional.

My HB500 MSX2 sony has not any mapper and 64k of ram.

I read somewhere the trick to expand the panasonic
FSA1-FX which has only 64K of memory , and it was
clear that this computer had the mapper eventhough
it had only 64K of ram.

We're talking strictly MSX2+ here, but thanks for the info anyway

I rember that I have seen something about the msx2+ standaard in a magazine.. was it mcm?.. Don't remember, but do rembemer that a DD diskdrive and the vdp ports are also standardised.

Yup, that's what I remember too.

I think it was mcm. wasn't there artical database of mcm?

Something else that is also part of the msx2+ (I think it, not 100% sure) is the detection between software resets and hardware resets.. roms that are still in ram do not restart after a hardware reset,but do after a software reset