About UR: that 'real time scope' part does not really suffer from the V9958, but more from slightly different timing on turboR.
You're right about the 4MB RAM: 2MB is safer and still more than plenty.

Quote:

About UR: that 'real time scope' part does not really suffer from the V9958, but more from slightly different timing on turboR.

Oh, I thought that I saw it bad working in a MSX2+ Sanyo Wavy FD (RAM 512KB) in the old days. But, of course, too much time since then has passed.

That part also "suffers" more with 10MHz in OCM (this seems not to be well "synchronized" or it is too much focused to a 3.58MHz z80).

It could be that the Sanyo has different timing as well.

The horizontal screen split relies on very tight timing, so it will definately be messed up on differently timed machines.

> KdL

At the time of having written the mail I thought that it was a
good proposal.
However, the noise increases when SPDIF is connected directly.
Because the inside of OCM outputs the voice by the sampling rate of 3.58MHz.
It is necessary to design the low-pass filter of the cutoff frequency 48kHz on 3.58MHz to prevent
the noise.
It is too large, and doesn't fit the free area of OCM.

I have another idea.
It only has to output the voice to a port away from the VGA output.

About 4MB

In software for Mappar RAM, the number of 16KB-RAM is counted.
In the software counted by 8bit register, it fails in the detection of 4MB.
The 4MB has 256blocks.
It overflows when it is 8bit.

I know there is such a problem.
As for the software that will be made in the future, I want you to make as much
as 4MB consciously.


OCM becomes 2MB by changing EMSX_TOP.VHD.

What is UR?
Is UR free software?

In the source of original ESE-VDP, comment "The problem is
brought up by the horizontal split of UR" on Japanese.
I corrected ESE-VDP disregarding the comment.

UR = Unknown Reality, Dutch demo from 1994 by NOP. The music was composed by Compjoetania and it uses MSX Audio + MSX Music. It even uses the 256KB of sample RAM from Philips Music Module (MSX Audio).

Yo can download it for free from here:

http://www.msx.org/modules.php?op=modload&name=Downloads&file=index&req=visit&lid=222

Quote:

In software for Mappar RAM, the number of 16KB-RAM is counted. In the software counted by 8bit register, it fails in the detection of 4MB. The 4MB has 256blocks. It overflows when it is 8bit.

The problem is that there is software which won't work and we can't modify that software. For future software I hope it won't happen again.

Anyway, I think most of actual coders will care of it as you point. We want OCM as a perfect MSX but we have to create compatible MSX software too (it does not happen most of the times though).

As for EMSX_TOP of the latest version, the refactoring of VDP is the main.
The timing of VDP may be getting worse.
However, it is easy to adjust timing.

I am creating the benchmark which measures various timing now.
In the next release, I think that some conspicuous bugs are solvable.

Moreover, in the next release, it returns to 2MB Mapper RAM.

SaebaMSX: Yo can download it for free from here

Thank you!