One chip MSX improvement project

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By beachsun

Supporter (4)

beachsun's picture

10-07-2009, 22:55

Message for Caro or HRA! :
Any chance to get your Msx implementation on a Altera DE2?
TIA

By caro

Hero (513)

caro's picture

11-07-2009, 03:52

Any chance to get your Msx implementation on a Altera DE2?
I unfortunately do not have DE2, otherwise I would have done.

By beachsun

Supporter (4)

beachsun's picture

11-07-2009, 10:14

Caro : thanks for you answer. Any idea how hard could be the implementation on DE2? I'm looking for an altera board and this can be an important point

By vanfanel

Champion (446)

vanfanel's picture

11-07-2009, 15:44

Is "MEGA-SD.ROM" needed in the sd card of the Altera DE1 in order to boot? What's that file?

By caro

Hero (513)

caro's picture

11-07-2009, 18:08

Is "MEGA-SD.ROM" needed in the sd card of the Altera DE1 in order to boot?
The loader system for last core HRA provides two options:
1) Load ROM-Files from SD-card;
2) Booting compressed ROMS from internal FLASH-ROM (EPCS4);

Description of the boot procedure (IPL ROM)

    * copy IPL ROM contents from 0000h to FC00h:
    * set palette and execute contents at FC00h
          - read boot sector from SD
          - find 'FAT' text,
            decompress and copy ROMs from flashROM (EPCS4) if not found
          - find first DATA sector
          - read the sector
          - check for 'AB' signature,
            decompress and copy ROMs from flashROM (EPCS4) if not found
          - read sectors and copy ROMs from SD-card

Loading System ROMs from SD-card

    * the SD-Card must be FAT12 or FAT16 formatted
    * when using loose files the max. cluster size is 16 kB.
      Larger cluster sizes need the ROM images concatenated into one 392kB file.
    * the ROM images must be the VERY first file(s) on disk and be unfragmented
    * the ROM images are loaded from sector in order:

  65.536 (00-07) (DISKBASIC)   OCM-MEGASCSI.ROM    MEGASD.ROM
  32.768 (08-11) (MAIN-ROM) (FS-A1WSX)             MSX2P.ROM
  16.384 (12-13) (EXT-ROM)  (FS-A1WSX) (MOD_$2C8D) MSX2PEXT.ROM
  16.384 (14-15) (SUB-ROM)  (FS-A1WSX)             MSX2PMUS.ROM
 131.072 (16-31) (KANJIDATA)   OCM-KANJI-128KB.ROM KANJI.ROM
  16.384 (32-33) (SLOT0-1) ($0000-$3FFF)           FREE16.ROM
  32.768 (34-37) (SLOT0-1) ($4000-$BFFF)           MSXKANJI.ROM
  16.384 (38-39) (SLOT0-1) ($C000-$FFFF)           FREE16.ROM
  16.384 (40-41) (SLOT0-3) ($0000-$3FFF)           FREE16.ROM
  16.384 (42-43) (SLOT0-3) ($4000-$7FFF)           XBASIC2.ROM
  16.384 (44-45) (SLOT0-3) ($8000-$BFFF)           FREE16.ROM
  16.384 (46-47) (SLOT0-3) ($C000-$DFFF)           FREE16.ROM

If you put KANJI-BASIC to slot 0-1, replace MSX2+
SUB-ROM bytes (#3A,#F8,#FA) in address #2C8D with #3E, #84,#00
If the KANJI-BASIC is in slot 0-3 replace the second byte with #8C

By caro

Hero (513)

caro's picture

11-07-2009, 18:29

My latest stable release OCM on Altera DE1 of 15.06.2008 are: www.msx.k66.ru/08_06_15.zip

1) Includes works !HRA for VDP9958 of the stable version for the OCM
dated 11 May 2008.

2) Edit the clocked system.
Instead, the basic frequency of 27 MHz, 50 MHz frequency used.
As a result, the main frequency OCM_DE1 became equal
50 * 3 / 7 = 21.43 MHz rather than 20,925 (for the OCM = 21.477 MHz)

3) Edit Audio Codec. Clocked from 27 MHz.
Bit-rate increased to 98 kHz, to improve play
Sound of OPLL-synthesizer, whose basic frequency
sound slots = 49 KHz.

4) Off the management of individual loudness of sound synthesizers.
Remained only to regulate the total volume (PgUp, PgDn).

ROM-file for recording to SD: www.msx.k66.ru/roms_m2p.zip

By vanfanel

Champion (446)

vanfanel's picture

11-07-2009, 18:53

Thanks for you help, Caro! I'll try your latest implementation on monday as I'll get back home, and I'll post the results.
I thank you for your hard work! My ALTERA DE1 has a fabulous future as my new MSX2! Big smile

By Devcon

Resident (41)

Devcon's picture

11-07-2009, 18:57

WOW, thanks a lot caro !

All the needed in one single package, thanks for your patience with us the newbies Smile

The truth is that !HRA and you have done both a pretty good job.

Testing on the Altera board now Smile

By vanfanel

Champion (446)

vanfanel's picture

11-07-2009, 18:59

Post results, Devcon, my unknown newbie bro! Big smile

By Devcon

Resident (41)

Devcon's picture

11-07-2009, 21:56

Well, i tested the board and all i can say is it's so great, it's like playing on an original MSX machine (i have two of these), the experience and feel is better and realistic than the one the existing emulators offers (with all my respect).

The 3 games i tested works great with "ngload".

The only thing that annoys me is that my 17'' CRT monitor flickers a lot at 60HZ, and my eyes are suffering. I think most CRT monitors at 640x480 can manage a frequency of 120HZ perfectly. Don't know if it will possible to put the VGA output of the board at 120HZ maintaining the VDP frequency at 60HZ.

But for the rest, all i found is perfect Smile

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