Trying MSX SUPER TURBO in Msx2 HB-F9s...

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By RetroTechie

Paragon (1563)

RetroTechie's picture

08-11-2010, 01:21

The only pin in 27C512 that is not conected into socket in IC12 is the PIN1 that goes in the air and conected directly to PIN5 in Z80, all other pins are connected directly to IC12 Socket.
With A15 @pin 1 the correct address would be selected in the EPROM, but with #CS01 as output enable, the EPROM would be disabled for reads from 8000-FFFFh. Meaning that indeed you'd be having MSX2+ ROM in page 0 & 1, but not in page 2. I'd expect some of the (Japanese) 2+ extra's not to work, maybe Kanji modes won't work or some Kanji characters blank... Question If everything seems normal, you might leave it be & perhaps try a fix once you discover what the (software) effect is. Correct hookup would be #SLTSL at pin 20 (as it is now), and equivalent of (#MREQ and #RD) at pin 22. But doesn't look like you can pick up that signal in the machine (read: would need addition of a small logic IC to produce it Sad ).

Could you type here the test lines code to try in Basic? Thanks
Oh I meant something simple like:

10 PRINT "*";
20 FOR N=1 TO 5000: NEXT N
30 GOTO 10

Just so that you can see effect of turbo, and whether machine keeps running or not. Adjust delay in line 20 to taste.

when utility Sinfox FLASHMAN is use to load any .rom game and the Sinfox SCC is in Mute mode the .rom games will run using SCC inserted for example in SLOT2?, using the FLASHMAN tool i can load .roms but if i´m right there is no FLASHMAN options to select SLOT where the SCC is inserted when i load the .rom.
Hmm... good point. So perhaps you'd want to disable the SCC chip itself instead of sound output. But that also wouldn't work because Synfox cart uses the SCC for bankswitching.

Is there any examples or documentation to try the SCC mute switch?
Just a switch in the sound signal going to SOUND IN pin on cartridge slot?

By Dhampird

Hero (585)

Dhampird's picture

21-11-2010, 07:46

Hello again, finally i tried the Megaflashrom SCC+, the cart dont support Turbo Mode ON, the msx hangs, then i installed a minipc in hb-f9s mainboard with 2pinouts and 1 jumper to be able select between fixed 3.58Mhz CLK signal to SLOT2 or Turbo CLK OUT to SLOT2.
With the jumper in 3.58Mhz position the cart works perfect in Turbo Mode ON, also the increase speed works, only i could notice some sound drops when Turbo is ON but for now i couldn´t try much games, could be any problem in .rom game? Seems like this drop sound happen not always or every 10 minutes during 3 or 4 seconds, as if missing some channels on the sound or sounds lower, I wonder if this happen because the MegaFlashROM use SCC + and the games than i tried use SCC and it will need to be patched.
The Megaflashrom SCC+ seems then that not support 8Mhz, the cart is built only with 2 IC´s: XILINK SPARTAN XC3S50AN and M29W800DB.

About MMC/SD Sinfox v.2.2, if the cart is conected in SLOT2 with jumper place in CLK 3.58 Mhz and Turbo is ON, the cart dont boot ok, hangs in the load process if SD´s are conected, algo hang in msx-dos2 if Turbo is enabled, but if i load a game with TURBO OFF and when game is loaded i set TURBO ON, runs ok. This is probably due to what you said "..but if I'm not mistaken the SD/MMC logic uses the CPU clock to synchronize Flash card <-> Z80 transfers?", i mailed me with L.Padial and i´ll send the Sinfox to try 3.58Mhz oscilator only for SCC, then the Sinfox could be used pefectly in SLOT1 with TURBO ON and with perfect sound for SCC.

By sd_snatcher

Prophet (3093)

sd_snatcher's picture

19-04-2011, 23:05

So S1985 uses clock only for DRAM timing & PSG - thx for confirming that.

The clock also seems to be used for:

a) generating the #WAIT signal at the M1 cycle
b) generating /CSW and /CSR signals.
c) generating additional waitstates after VDP I/O if the /X7 was configured to "1" on reset

See the S1985 datasheet, pages 38 and 40, for more info.

If your machine was upgraded to MSX2+, you could disable the I/O slowdown to 3.57MHz by connecting the V9958 #WAIT to the Z80 and enabling the signal on R#25. The I/O would then occur entirely at 7MHz without trouble.

1) Does the HB-F9 has the Rensha-Turbo (aka slowmotion controller) like the Sony HB-F1XD* series has?

2) Is your HB-F9 upgraded to MSX2+?

By Dhampird

Hero (585)

Dhampird's picture

21-04-2011, 03:12

Hi, sd_snatcher thanks for reply. Time ago i read about #WAIT vdp and z80 but i didnt find a way to install in the HB-F9s, i mean that if i have to conect VDP out #WAIT signal to Z80 #WAIT directly, or if i have to add some circuit or resistor or diode in the middle of that connection, also i see that #WAIT appear for S1985. Will be needed desolder #WAIT Z80 pin from motherboard or not?. Please try to explain me more about it if you can, will be great try this #WAIT option in HB-F9S. What did you mean with "signal on R # 25"?.

Does the HB-F9 has the Rensha-Turbo (aka slowmotion controller) like the Sony HB-F1XD...
No, there isnt any device like that.

Is your HB-F9 upgraded to MSX2+?
Yes, it is.

Also i have installed STATIC RAM AS6C4008 512K, and in SLT 3-3 512K more LPE-512KBSRAM-V3, Z80 is 8MHZ CPU Z84C0008PEG, MSX2+ EPROMS (27c512)90ns and (27c256)70ns, F4 REGISTER, and obviously VDP9958, and MSX SUPER TURBO.

Thanks for new ideas.

By sd_snatcher

Prophet (3093)

sd_snatcher's picture

22-04-2011, 07:09

@Dhampird

It's a nice machine you have! Smile

Besides the S1985 chip, does your machine has another chipset on the motherboard? I mean, other sony machines always feature a second chipset, by Sony, like the Sony MB670836

The R#25 I mentioned is the V9958's register number 25.

About the V9958's #WAIT pin: The V9958 datasheet omits this information, but that pin output is open-collector just like the #INT pin. This means you can connect it directly to the #WAIT line of your MSX (either directly to the Z80 socket or to the #WAIT pin of any slot).

But before doing that, please run the game Theseus on your current setup and see if there's any corruption on the screen. If you can, record a video of it so you can compare the performance with the improved setup later.

The V9958 was designed with turbo machines in mind and natively supports 7MHz I/O when the #WAIT is correctly connected and enabled, and this will improve a lot the speed for raster effects, like splitscreens.

To use this wonderful built in #WAIT generation, proceed as this:

1) Disconnect the I/O slowdown feature of your SuperTurbo, which is in fact is needed only for the V9938. This means you'll disconnect the wire that comes from the Z80 I/O pin to the slowdown diode-and of the SuperTurbo.

2) Solder a wire connecting the #WAIT pin of the V9958 to the #WAIT pin of the Z80. You don't need a pull-up resistor because there's one present on the motherboard already.

3) Supply the same clock that the Z80 has to the S1985, otherwise /CSW, /CSR and /WAIT signals will not generated properly. I'll provide a suggestion for fixing the PSG sound later, if this V9958 #WAIT mod works fine on your machine

4) Activate the #WAIT generation by the V9958, type the following command on MSX-BASIC:

VDP(26)=VDP(26)OR4

5) To deactivate the #WAIT generation, type the following command:

VDP(26)=VDP(26)and &HFB

Please test the game Theseus both with the #WAIT enabled and later with it disabled to compare the results. Also, please compare the Theseus speed now with your previous recording that had the I/O slowdown to compare the game speed difference.

If you can, please compare the disk access speed under MSX-DOS2.

By sd_snatcher

Prophet (3093)

sd_snatcher's picture

22-04-2011, 07:56

Do you have the schematics of the F4 register (aka reset status) you implemented on your machine?

By Dhampird

Hero (585)

Dhampird's picture

22-04-2011, 23:05

Hi, sd_snatcher, thanks a lot for fully explanation, i´ll try it this week, meanwhile here are the complete info needed for F4 register that i installed in HB-F9s:

www.msx.org/forumtopic12057.html

I have any other diagram, only explained in the post but with no picture, i didnt find your mail, i can send to you all same info explained in the post above with any more diagram, maybe if you have some time you could mail me to: dumpil@gmail.com and i´ll attach to you that diagram, i´m dont sure if is one or two more that dont appear in post, will be great also talk about #WAIT mod because probably i´ll have to ask to you something in some part of the process.

Thanks a lot again for help and right guideance.

By sd_snatcher

Prophet (3093)

sd_snatcher's picture

22-04-2011, 23:54

@Dhampird

You got an e-mail. Smile

By Dhampird

Hero (585)

Dhampird's picture

23-04-2011, 01:58

OK, i sent also two mails, take a look.

By Dhampird

Hero (585)

Dhampird's picture

18-10-2011, 05:49

You can follow some new tests with MSX SUPER TURBO and other features in this post: www.msx.org/forumtopicl13586.html

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