Some years before, i remember i experimented some &h instructions (or sumthin' like that) on my FSA1-WX which was claimed to boost it to 7mhz.
I experimented this 7mhz trick with maarten, but droped it because we didn't find a way to boot the computer with it then launch a game/app.
I can recall maarten experimented alittle prog that loaded the &h instruction in the ram of the SCC+ of Snatcher but it was very preliminary and didn't allowed the FSA1-WX to launch a game/app.

Anyone know if this instruction realy works and if it's possible to launch apps or games after boosting the comp to 7mhz ?

Panasonic A1-WX/WSX/FX extension
#40 = 8 (Panasonic manufacturer ID)
#41 bit 0 = 0: High speed mode (switch to 5.37MHz mode)
bit 0 = 1: Low speed mode (regular 3.57MHz mode)

LD A,8
OUT (040H),A ;out the manufacturer code 8 (Panasonic) to I/O port 40h
IN A,(040H) ;read the value you have just written
CPL ;complement all bits of the value
CP 8 ;if it does not match the value you originally wrote,
JR NZ,Not_WX ;it is not a WX/WSX/FX.
XOR A ;write 0 to I/O port 41h
OUT (041H),A ;and the mode changes to high-speed clock

The trick to enable 6MHz is OUT 65,8UT 64,0

There should not be any problem to launch applications after that. To play for example disk game, that has sector loader, typically this trick works:
POKE &HF346,1:_SYSTEM

~NYYRIKKI

i am not sure to understand...

For example, how do you launch this trick when using the MetalGear2 English translation disc which is autoboot ?

Is there such a trick for Turbo-R ?

1. Leave the disk out of the drive when booting. (On turboR you're now automatically in R800 mode and you can skip the next step)
2. Use OUT 65,8UT 64,0
3. Insert the disk, and depending on how the disk is booted, try:
RUN "AUTOEXEC.BAS"
or
POKE &HF346,1:_SYSTEM

Et voila, you're playing high-speed dildo!

Quote:

1. Leave the disk out of the drive when booting. (On turboR you're now automatically in R800 mode and you can skip the next step) 2. Use OUT 65,8UT 64,0

Bad idea... tR will be in R800 mode, but also in DOS2. At least older games don't usually like DOS2. On MSX tR it is better to do it like this:

1. Leave the disk out of the drive when booting and hold key "1" to get into DOS1 mode.
2. Type: DEFUSR=&H180:A=USR(0)
... rest of the instructions are same. This trick works, but it does not turn on turbo mode led.

~NYYRIKKI

Thanks you all.

By the way i have another question :
i heard the TurboR was slower in Z80 mode than any other MSX2/2+.
Actualy i must admit games run a bit faster on the FSA1WX or HB700 than on the TR-ST.
(I didn't try the TR-GT tho)

You experienced the same things ?

Quote:

By the way i have another question : i heard the TurboR was slower in Z80 mode than any other MSX2/2+.

This is true only in BASIC. MSX2+ is slower than MSX2 and MSX2 is slower than MSX1.

This is due to added complexity in the Interrupt Service Routine and BASIC interpreter.

ok, i understand.

I guess every ppl that own a panasonic MSX2+/TurboR use this 7mhz trick all the time, a lots of things should benefit from the tiny power gain it should offer ?

Is this trick available for Panasonic Msx2+/TurboR or does it work on other MSX ?

As for as I know not, the 7.17Mhz extentions build in the netherlands are only switchable by a switch .. To bad they din't use this same I/O port for this.

Quote:

ok, i understand. I guess every ppl that own a panasonic MSX2+/TurboR use this 7mhz trick all the time, a lots of things should benefit from the tiny power gain it should offer ? Is this trick available for Panasonic Msx2+/TurboR or does it work on other MSX ?

The 5.3MHz trick is only on Panasonic MSX2+'s, not on turboR.
And the 5.3MHz is probably similar to the 7MHz upgrade kits, in the sense that they speed up all sound frequencies (PSG, FM, etc) so everything sounds really high-pitched.
However, 5.3MHz might just still be slow enough for the VDP to handle, so it's possible that one doesn't switch back to 3.58MHz all the time (like 7MHz upgrade kits do) and the higher pitch is bearable. (Coz on 7MHz the frequency goes up and down with writing to the VDP)

The vdp starts to generta errors already at 4Mhz. Btw the switching back doesn't genere extra delays or something like that.. it's simply temorarely slows down the cpu freq and only when I/O access is requested .

Ok, only the MSX2+ from panasonic can be overclocked using this trick but does it work fine except the sound pitch thingie ?

I mean : will progs or games benefits the new speed improvement or will it hang and bug now and then ? You said it would generate errors so iam not sure it's a good idea to boost the Z80 ?

When msx 2 computers are modified to 7.16Mhz also the cpu is replaced with a Z80H.. and yes the sound of the psg ,scc,msx-music and msx-audio is currupt.. only the opl4 works good on 7.16Mhz because it has it's own oscsilater. Offcourse lot's of games can make use of the opl4.

Quote:

Ok, only the MSX2+ from panasonic can be overclocked using this trick but does it work fine except the sound pitch thingie ? I mean : will progs or games benefits the new speed improvement or will it hang and bug now and then ? You said it would generate errors so iam not sure it's a good idea to boost the Z80 ?

By using Panasonic overclocking feature or by using R800 you can not break anything, if you mean that. I have not experimented any other than some sound problems. In R800 mode PSG works fine, but with overclocked Z80 the PSG shifts one octave up. This can be solved with software, but I don't know if any program has been made to support this.

What comes to FM-PAC or MSX-Audio the soundcard may loose some music data when it is outputted to music extention too fast. In MoonBlaster replayer (that is probably the most used replayer now a days) the R800 support is made by detecting the CPU and selecthing correct routine before starting to play. There is no 7MHz support by default.

In general:

If you play games, there is no reason to boost your MSX speed. Games are typically ment for 3.5 MHz and other speeds may cause unwanted actions, like line interrupt coming few lines too early or disorded music. You anyway may want to try for example Elite on R800.

If you use utilitys like text editing, ML compilers or similar, the extra speed might be handy.

Ps. You can change to R800 from DOS1 with this BASIC program:
10 A$="!a@-))TZ2"EFUSR=32777! :IFD2THEN LINE>2COPY0LOADATTR$ELSEA=USR(0)

... more info from this forum topic: www.msx.org/forumtopic1429.html