I was wondering if there are still msx users that would like a 8mhz expansion in the msx.

Let me know, as at this time i have a working expansion

Me !

Just as interesting:

Ofcourse a faster computer is always nice, but what specific applications / uses would you *use* the turbo setting for? That is: most important reason(s) for a speed upgrade, apart from 'want to have' or 'use it on turbo all the time' ?

1-
when i do 'dir' in dos it is much faster and convinient with 7MHz
this is not a joke ! very frustrating to see that slow text scrolling.

2- I want to try a new idea for a game dev for instance , quickly, in
basic and i know it is not asm and optimized but i want a bit faster
speed to get something closer to optimized asm running @ 3.5MHz

3- Compilation time : i use gen80 / turbo pascal and i do many
iterations : like little modifications + compilation ( can last few minutes )
and after using a turboR or 7Mhz or even 5MHz it is har to get back
to normal speed. of course from time to time i see what i looks on normal
speed msx's.

4- Boost disk speed ; when you deal with 32kb/64kb images for instance
or EVA player ... backup an entire directory , copy many files ...

5- Symbos

6- i am sure there are others , like few games like dungeon & dragons ....

I can get the z80 working on 10Mhz and the clock generator chip
In fact I ordered a couple of them already and hope to have them soon.
If anyone is interested in these chips or a working expansion then let me know

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I can get the z80 working on 10Mhz and the clock generator chip In fact I ordered a couple of them already and hope to have them soon. If anyone is interested in these chips or a working expansion then let me know

Is this mod compatible with any MSX model?
Are there big modifications to do inside or just replace Z80, solder awire here and there?

As 7 Mhz mods, is sound affected from this?

As MSX base speed is 3.579545, i suppose your kit should run at about 10.738635, doesn't it?
This means speed x 3. Nice...

By the way, how much does it cost?

Well the part I ordered are just the most important parts for that standard 7Mhz kit.
But these are the very hard to get parts. The rest is easy (caps, resistor, x-tal)
if you just want the 2 chips it will cost you 20 euros.
I have no kit yet as I first want to expirement with it in one of my 8250s

and instructions about this can be found at HansO: http://msx.retro8bits.com/clock-upgrades.html
Only problem is that Hans is temporarily out of bandwidth

I have installed once a kit in a vg8235 , what is painfull is to de-solder the old z80.
I have a hb700 i hope it is just on a socket !
...
BTW i was looking into into this recently , because there are z80 clones that are
able to execute one instruction per cycle ( instead of 4 ) like the r800 so you gain
a lot at the same clock speed , it would be more simple just to replace the chip without
extra wire , the problem are :

- you can't switch back to normal speed : if you have many msx's you can have one stuck at high speed.
- as many as i have seen, all these clone are not available in dil40 package , pin compatible ... you
have to make a smal pcb adaptor .. not easy ...

For instance there is the kawasaki kl5c80A12

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Only problem is that Hans is temporarily out of bandwidth

Will be back August 1, which is tomorrow.
I am grateful the site is so popular, its not just one stupid downloader.
Julio Marchi from MSX ALL, who supplies the MSX sites and bandwidth for free, gives us more and more each month

More uploads tomorrow also, found some interesting material again.

Also lots of games gain from the extra speed up.

I'm also making a small circuit to make the fmpac and musicmodule play correctly on 8mhz (already tested and working)
I just give them their own clock signal of 3,579 mhz. Unfortunately the PSG is built into the engine so i cant do that one (I'll try to find some other way to fix that)

Undeadline is the best example with its flashing sprites it will play much better with the 8mhz expansion.

Ofcourse I also can build it in your msx for you.

10mhz did not work on the 8220 maybe with some more adaptations and replacing LS chips with HCT chips will work as LS can go up to 4mhz.

With only the CF interface 8,8mhz is working.

Basicly atm its like removing the Z80 put in the new and solder two wires, some MSX computers need an adaptation on the mainboard. New resister array for the keyboard and some rerouting to the engine.

Benefits?

Quoting Leo's comments:

1- Say yeah!. MSX-DOS sometimes feels sluggish, specially when floppy is accesed.

2- MSX-BASIC would be kicked as hell indeed. And C/Kun BASIC programs would be even more rocketed.

3- Die-hard fans of MSX development would be extremely happy with that...

4- As I've already mention before, floppies are slooow. Standard Z80 speed can't cope with the maximum bandwith that a CF/SD interface can provide; even more benefits.

5- SymbOS + GFX9000 + 7/8Mhz, yay!. Yes, I know, I already have this combo (@10Mhz) using the OCM; but I'm not a big fan of this device.

6- Few games?. Virtually ALL the Spectrum conversions lack speed....and some of them are pretty funny games. Heavy MSX2 native games could also benefit from this speed up.


.....but, can anyone list the cons?. I suposse that the sound would be severely distorted, maybe some peripheral devices would suffer of synch problems, such kind of things...

Anyway, I'm interested for sure!

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I have installed once a kit in a vg8235 , what is painfull is to de-solder the old z80. I have a hb700 i hope it is just on a socket !

Yup, that's normally the hard part of a clock upgrade, and where it often goes wrong (pcb tracks damaged etc). Best is to always replace Z80 first (use socket or not for new Z80: your choice), and then test if the MSX still works, without making any other changes. If everything ok: proceed with re-routing clock signal etc. Btw. Z80 won't be socketed in a HB-F700 in factory state... good luck

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Well the part I ordered are just the most important parts for that standard 7Mhz kit. But these are the very hard to get parts.

The clock generator IC used in that kit is hard to find, but you can do without (see MSX Super Turbo). Faster Z80's are still manufactured, and used for all sorts of embedded stuff / co-processor for industrial control etc. 8, 10, even 20 MHz. versions can be found (DIP, PLCC or Flat Pack housings), and popular types hover around 4~5 Euro's a piece. See for example Digikey, Farnell, or some eBay stores. It's just your local electronics shop that won't have 'm. Got some 20 MHz. Z80's myself (these don't work well in MSX machines due to fast output switching w/ long pcb traces - better suited for small circuit boards). As others noted there exist non-hardware compatible, but waaay faster varieties like eZ80, Rabbit, or that Kawasaki thingie.

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I'm also making a small circuit to make the fmpac and musicmodule play correctly on 8mhz (already tested and working) I just give them their own clock signal of 3,579 mhz.

A nice way to fix that is to give 1 cartridgeslot a fixed 3,58 MHz. clock, and use that for sound cartridges. Then let the other cartridgeslot output the CPU clock, and use that for things like memory mappers. Easy, and then you can leave cartridges unmodified.

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Unfortunately the PSG is built into the engine so i cant do that one (I'll try to find some other way to fix that)

The clock is also used in the engine to time DRAM control signals. That would make this a non-fixable problem, unless you get rid of DRAM as internal memory (read: replace internal memory with SRAM). Can't say I tried that, though.

IMHO a clock upgrade is only worth the trouble if you would use it a lot, if it's relatively easy (say: 3,58 -> 7 MHz on a common model MSX), and you don't mind the work or paying someone to do it for you. If you want to go much faster, it's easier to buy or build an entirely new machine: Turbo-R, 1chipMSX, FPGA development board, ...

I am indeed using the MSX Super Turbo kit with the easy to get parts and dont mind doing upgrades for anyone.

10mhz is not working for a philips 8220 and 8,8mhz is unstable. 8mhz seems to work fine but a resistor array for the keyboard has to be replaced.
I am using the Z84C0010PEG which can go up to 10Mhz and is fully compatible with the used Z80 in the MSX.
The normal 7mhz print and MSX Super turbo print do have a connection in the scematic which does not speed everything up enough (For the novaxis SCSI interface there was barely any speed increase) This problem has been fixed and can also be done on the regular 7Mhz print.

But first I want to try some extra things like also putting an fm-pac on the board