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

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By Manuel

Ascended (15839)

Manuel's picture

29-08-2010, 14:23

FYI: I've ran MSX Super Turbo with 8MHz for years without any problems in my Sony HB-G900P.

By Dhampird

Hero (585)

Dhampird's picture

31-08-2010, 23:25

Finally, i did the reconect S1985 pin 30 to VDP's 3.58 MHz output, cutting and reconecting the track pin 30 S1985 like show in this final diagram:

a.imageshack.us/img265/9501/msxsuperturbofinaldiagr.jpg

Now the PSG sound in games sound normal when the is Turbo ON, i tried with some games and no problems with Sound now, perfect working. I tested Vampire Killer and Metal Gear, among others who use PSG, and sound is perfect now in Turbo Mode!

Also i placed a 8Mhz crystal in Msx Super Turbo, because I could not get 7Mhz crystals types for now, with 8Mhz the speed in games is quite noticeable, like nemesis saga and others. I dont have any msx joystick or another msx peripherals to test for if there could be problems with them and the 8 mhz, the keyboard for example does not seem to experience problems at 8Mhz, anyways i´ll try with 7mhz´s types when i´ll get some. Gives the feeling that for some games the 8mhz is too fast for playing, for example in Nemesis at 8Mhz now you have to pressing the space bar more kickly to try shooting the space-ships, i think 8 MHz may be too fast in some games.

Metal Gear 2 with Msx Super Turbo at 8mhz (you´ll see the difference between Turbo ON and Turbo OFF very easy, the video is a little blur but I think quality is more than enough to see how fast Snake walks across the screen):

www.youtube.com/watch?v=3c3lv83wKJU

About crystals I did a search on an online store and have:
6.144MHz, 6.176MHz, 6.5536MHz, 7.3728MHz, 7.68MHz, 8.192MHz, 9.8304MHz

No 7.16 ,8.87 and 9.22 to choose for now. About 9Mhz type, if 8Mhz is so much, why to try with the 9mhz? only for test if the Msx is stable at 9Mhz?

That shop have 7.3728MHz, i´m trying to search about the others if not appear in another shop. i think that i´ll should get:
6.176MHz, 6.5536MHz, 7.3728MHz, 7.68MHz

I´m speculating... but I wonder if It would be possible to use for example a 10MHz crystal in Msx Super Turbo and somehow get to work that crystal on different frequencies using any software program that runs in msxdos 2. I guess this would have to change the original circuit pair to do something like that if this will be possible.

Well, then i think that the Msx Super Turbo install in HB-F9s is done, would remain to try some crystals and when i tried it i´ll post again. If i missed any test or possible to do anyone more please tell me.

"Thanks a lot to you RetroTechie for guiding me through the installation, without your help I would not have been possible to install and test MSX Super Turbo on my hb-f9s. Thanks a lot for the fully help"

By RetroTechie

Paragon (1563)

RetroTechie's picture

01-09-2010, 01:12

So S1985 uses clock only for DRAM timing & PSG - thx for confirming that. Smile2

i think 8 MHz may be too fast in some games.
Although some games may run smoother or feel more responsive, usually people want turbo upgrades for other reasons than games... ah well...

About 9Mhz type, if 8Mhz is so much, why to try with the 9mhz? only for test if the Msx is stable at 9Mhz?
Yup... the more datapoints you have what works @ what speed, and what doesn't work (especially cartridges & combinations of them), the better picture you get of what's 'safe', stable etc, what margins you have, or why/why not you'd run your machine at a particular speed. 7.68 and 8.19 Mhz are nice values that I'd like to have in my toolbox, but no idea if it would make sense for you to order those. Btw: have you tried 10 MHz or higher (just for kicks) ?

I´m speculating... but I wonder if It would be possible to use for example a 10MHz crystal in Msx Super Turbo and somehow get to work that crystal on different frequencies using any software program that runs in msxdos 2.
Question Software can't change either normal or turbo speed, period. All it can do is determine which of those is used & when.

"Thanks a lot to you RetroTechie for guiding me through the installation, without your help I would not have been possible to install and test MSX Super Turbo on my hb-f9s. Thanks a lot for the fully help"
No comment, or otherwise I'd insult you... Basically my webpage says you shouldn't have tried in the 1st place, so I guess you were lucky. Wink Dead HB-F9S would have been equally likely outcome...

By Dhampird

Hero (585)

Dhampird's picture

01-09-2010, 02:55

Hello Alwin, about...

"7.68 and 8.19 Mhz are nice values that I'd like to have in my toolbox"

The online electronic shop that i found also serves to Netherlands, try:

nl.farnell.com/crystals

(click on crystals Frequency needed in the left and then Resultaten in the right, this show up available products, i get the 8Mhz Z80 CPU new! from this web store)

"have you tried 10 MHz or higher (just for kicks) ?"

I have here 10Mhz and 14Mhz, but try that will be safe? especially that of 14MHz...

No comment, or otherwise I'd insult you... Basically my webpage says you shouldn't have tried in the 1st place, so I guess you were lucky. Dead HB-F9S would have been equally likely outcome...

That's because you've explained perfectly to me as taking the project forward, thanks again for that, and i think all this HB-F9s posts may help some msx.org users forum to dare to make a few Msx mods. Thanks a lot.

:P

By Dhampird

Hero (585)

Dhampird's picture

02-09-2010, 20:47

Hello, i tried the Msx SUper Turbo with a 10Mhz Crystal, when i tried this i had in SLOT1 the LPE-SANS soundcard and in SLOT2 the MMC/SD Sinfox, i turned on the MSX and with TURBO ON the MSXDOS2 from MMC/SD sinfox dont finish load, hang in blue screen, then i set TURBO OFF and i load a game, into game i set TURBO ON and the game crash! after the game crashed (TURBO ON still ON) the MSX goes to Boot Screen.

It seems then the 10Mhz is so much for the HB-F9s, 8Mhz seems work OK, but i´ll need to try also with joystick and another peripherals, i´ll try to find all crystals range from 8Mhz to 10Mhz.

More tests soon.

Regards.

By sd_snatcher

Prophet (3093)

sd_snatcher's picture

19-10-2010, 03:37


i think 8 MHz may be too fast in some games.

Many (not all) konami games have a bug on their timing routines. You get get a fix for some of them here, including Metal Gear 2 and Nemesis2 (aka Gradius-2). Have a look at the HD-games (hard-disk) session too for more turbofixes.

By Dhampird

Hero (585)

Dhampird's picture

20-10-2010, 06:46

Thanks for the tip "sd_snatcher" when i have some time i´ll try that fixed games...
Thanks a lot.

By sd_snatcher

Prophet (3093)

sd_snatcher's picture

21-10-2010, 22:10

@Dhampird
You're welcome!

It seems then the 10Mhz is so much for the HB-F9s, 8Mhz seems work OK

Isn't 10MHz too much for the Z84C0008PEG? To get up to 10MHz shouldn't you be using the Z84C0010PEC version instead? Or why not even try the Z84C0020PEC? Smile

@20MHz, the Z80 probably would be almost as fast as the R800.

By RetroTechie

Paragon (1563)

RetroTechie's picture

21-10-2010, 22:48

Most Z80's overclock really well so an 8 MHz Z80 will probably run fine @10 MHz.

The 20 MHz versions are bad choice in MSX2's - there are some subtle (but critical) timing differences, and fast switching outputs + large circuit boards is a bad combo. I have a couple of those Z84C0020PEC's, and tried in a 7 MHz-upgraded Sony HB-F700 once: 8 MHz (NMOS) Z80 worked fine at turbo & normal speed, the 20 MHz version worked (somewhat) okay @3.58 MHz, and froze machine @7 MHz. Even though specified for 20 MHz, I was not surprised to be honest... Cool For a 20 MHz Z80 to work reliable, you need a compact board (like in ZX81) with well done layout. And fast supporting circuitry that's designed to work with that 20 MHz part.

Also there's no point for a 20 MHz Z80 in an MSX2 that has its absolute limit around 9 ~ 10 MHz area, you can't clock a Z80 independent from rest of the system. All important parts (RAM, ROM, Engine, any signal buffers etc) have to keep up. You can exchange more parts for faster versions, but beyond some speed you need to change so much it's easier to build a new machine from scratch...Evil

By sd_snatcher

Prophet (3093)

sd_snatcher's picture

21-10-2010, 23:47

@RetroTechie
And what about a turbo kit based on this idea:

- Crystal1: 20MHz for internal operations, since many instructions take a lot of cycles
- Crystal2: 7MHz for RAM/ROM access (selected when /MERQ is activated)
- FromVDP: 3.5MHz, used for I/O (selected when /IORQ is activated)

Isn't that feasible? Smile

@Dhampird

Could you please try this setup as a draft test for the above idea: use 10MHz and connect both #IORQ and the ROM #OE to diode inputs.

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