OCM-PLD Pack 2.4

by KdL on 13-04-2011, 08:54
Topic: MSX Revival

A new version of the OCM-PLD Pack has just been released by KdL. New in this version:

  • New Switched I/O ports module
  • An additional cpu clock of 5.37MHz, tPANA with redirection possibility
  • A hybrid clock to get fast SD-Card access with any cpu clock, tMegaSD
  • Fine-tuning at 10MHz, controlled by [SHIFT+PGUP/PGDOWN]
  • T80 undocumented DDCB and FDCB opcodes
  • An additional French keyboard layout
  • New and improved RTC module
  • Many LED options and adjusted light intensity
  • Improved stability of [PAUSE] key
  • Fixed minor bugs on PS/2 keyboard interface module
  • Disabled OSD and Debug Window to cut LEs
  • Disabled SCC interpolation to cut LEs
  • Modified and updated the [msxtools\] folder
  • Modified hex-file to get easy a customizable MSX2 bios, mainly to have 80 columns, key click sound off, backslash and logo antialiasing fix
  • Updated DIP-SW User Manual and other documentation in the [esemsx3\docs\] folder
  • PLDs in this package: JP layout, UK yen, UK backslash and FR backslash

This release has been optimized with Quartus II 8.1 Web Edition using the options Ignore LCELL Buffers [On] and Force Use of Synchronous Clear Signals [On]. To keep up to date on the latest developments regarding the OCM-PLD Pack we strongly advise you to keep track of the One Chip MSX improvement project topic on our active MSX Forum.

Relevant link: KdL's website

Comments (14)

By caro

Hero (513)

caro's picture

13-04-2011, 16:01

Thanks, KdL!

By Sander

Founder (1872)

Sander's picture

13-04-2011, 16:57

Great news!

By KdL

Paragon (1485)

KdL's picture

13-04-2011, 17:25

just now, I've fixed bg color of smart commands table...
( damn to my eyes and lcd monitor eheheh Smile )

download it again, if u want this correction
Running Naked in a Field of FlowersRunning Naked in a Field of FlowersRunning Naked in a Field of Flowers


Master (172)

KNM's picture

13-04-2011, 20:34

Great news ! Keep OCM alive is pirceless ! Terrific job ! Big smile

By Grauw

Ascended (10820)

Grauw's picture

13-04-2011, 20:43

Great work!

Disabling the SCC interpolation though, is that really worth it?

By KdL

Paragon (1485)

KdL's picture

14-04-2011, 01:18

Hi Grauw! Hannibal
If you want it... you can always load the old firmware v2.3 Wink

SCC interpolation it is very big module that never been exploited,
and I've 680 free LEs without it... a good 6%!! (*)
Probably, this and more other space will be required for the future.
The same HRA! had removed it from his project and anymore:
- by default, the sound of games is like original on all ocm-pld pack versions;
- v2.4 have an improved scc module by HRA! again.

However, there are still sources in the
[\ocm-pld v2.4\esemsx3\src\sound\scc\sccic_support\] folder
--SCCIC references inside [emsx_top.vhd] and an [emsx_top.qsf.sccic] to rename.

Kind Regards. Smile

Fitter Status : Successful - Wed Apr 13 04:37:38 2011
Quartus II Version : 8.1 Build 163 10/28/2008 SJ Web Edition
Revision Name : emsx_top
Top-level Entity Name : emsx_top
Family : Cyclone
Device : EP1C12Q240C8
Timing Models : Final
Total logic elements : 11,373 / 12,060 ( 94 % ) <--------- (*) 12,053 and 1210 LABs ERROR with SCCIC and new features
Total pins : 171 / 173 ( 99 % )
Total virtual pins : 0
Total memory bits : 61,304 / 239,616 ( 26 % )
Total PLLs : 1 / 2 ( 50 % )

By spl

Paragon (1470)

spl's picture

14-04-2011, 01:29

Thanks Big smile

By KdL

Paragon (1485)

KdL's picture

14-04-2011, 02:41

ehm.. sorry, for this trivial thought:
>>> - by default, the sound of games is like original on all ocm-pld pack versions;] Evil eheh!

I mean that there is not an impressive difference and if it will be possible, I can enable it again.

You can hear these samples recorded @44khz:

Bye! :)

By RetroTechie

Paragon (1563)

RetroTechie's picture

14-04-2011, 15:58

SCC interpolation it is very big module that never been exploited,
and I've 680 free LEs without it... a good 6%!! (*)
Probably, this and more other space will be required for the future.

Perhaps it would be a good idea for (future) OCM enhancements to not just 'make things better' (as in more exact reproduced sound etc), but rather to weigh the cost of enhancements versus their gain. And with "cost" I mean mostly "complexity", as in: how difficult it is to understand (for others) how it works, how difficult that particular part of the design is to maintain etc.

Not so much to squeeze every last feature out of the FPGA that happens to be in the 1chipMSX, but more to make the OCM design more portable & futureproof. Simple change that is very useful for programmers & takes few resources: yes please. Large 'blob' that takes big chunk of FPGA resources to improve something in a very, very minor way: hmm... maybe better skip it & stick with a simpler option.

One idea I had myself: the i8255 emulation (I/O ports A8~ABh) - in the MSX system port directions are always set the same & basically fixed. There are some 'set bit X on port Y' commands for the i8255, but it wouldn't surprise me if it's hard (or even impossible) to find any software that uses this feature. If true, this whole thing could be simplified by replacing with plain 8 bit registers (with fixed direction & read/write behaviour), rather than a full i8255 clone. And if possible, BIOS code that sets the i8255 port directions could be scrapped too.

One question though: any chance to up the Z80 clock in future versions? Or would this require major rework, like entire re-design of DRAM control etc. Question

By Grauw

Ascended (10820)

Grauw's picture

14-04-2011, 21:16

Thanks for your reply KDL, even with samples Smile. 6%, that’s a lot for interpolation! I hadn’t thought it would cost that much. At least in regular code, interpolation is quite trivial, maybe if you would do some kind of adaptive interpolation it would be a little more complex but still…

I listened and although I do hear some differences, I agree it wouldn’t be worth that much. Maybe it can be recoded to be less expensive by um, someone Smile.

By ant0niutti

Master (159)

ant0niutti's picture

15-04-2011, 02:03

Good work!

By MicroTech

Champion (389)

MicroTech's picture

15-04-2011, 11:20

Great, thanks KdL!
I'll try asap

By KdL

Paragon (1485)

KdL's picture

15-04-2011, 18:04

Already now, the system hang using a full 10MHz and external cartridges are not all compatible with more clock.
It will be hard!!

Also there is too much noise on audio output to enjoy of interpolation:
while a digital output (S/PDIF) might make a sense! Smile


By mesiasmsx

Prophet (3454)

mesiasmsx's picture

20-04-2011, 00:40

Good job KDL!