For Sale : Panasonic Turbo-R FS-A1ST

Door rklok

Champion (280)

afbeelding van rklok

25-10-2011, 16:14

- Price : 275 euro
- Shipping Europe : 19 euro
- Info : ronnie@rklok.nl

Working 100%

www.rklok.nl/pics/TurboST.jpg

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Van Dreambeemer

Supporter (1)

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22-06-2020, 20:12

Mooi ding, werkt alles goed?

Van enrijavibox

Master (168)

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22-06-2020, 20:40

2011.......

Van Grauw

Ascended (9342)

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22-06-2020, 21:21

Prepare to pay at least double nowadays Smile.

Van Meits

Scribe (6011)

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23-06-2020, 02:23

Yeah. Seen them for 700 and more. Strange to see they're nearing their retail price.

Van djh1697

Paragon (1485)

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24-06-2020, 16:47

There is virtually ZERO software in English that uses the TurboR features, MSX2+ with a Turbo button would probably be just as useful!

Van uberjack

Champion (265)

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24-06-2020, 22:47

I've yet to see a Turbo-R go for less than $700

Van Meits

Scribe (6011)

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25-06-2020, 11:14

djh1697 wrote:

There is virtually ZERO software in English that uses the TurboR features, MSX2+ with a Turbo button would probably be just as useful!

There's quite a big difference between the speed of a turbo MSX2+ and the R800. On top of that, an MSX2+ in turbo mode does affect the PSG in an undesired way; it goes up, but since the frequency is not twice as high, it does not go one octave and will therefore collide with the SCC or FM-PAC.

Van Grauw

Ascended (9342)

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17-09-2020, 22:17

Meits wrote:

On top of that, an MSX2+ in turbo mode does affect the PSG in an undesired way; it goes up, but since the frequency is not twice as high, it does not go one octave and will therefore collide with the SCC or FM-PAC.

Specifically, the tone frequency is 1.5 times as high, matching the ratio between 3.58 MHz and 5.37 MHz. That’s almost exactly 7 semitones.

Software specially built for turbo mode can compensate for that, however you can’t just run existing games in the Panasonic MSX2+ turbo mode without additional modification of the PSG player code’s frequency conversion table.

Then again, you often can’t run games in the turboR R800 mode either without additional modifications (I never do) because the games often don’t take such a big CPU speed increase into account and may for example access the MSX-MUSIC too quickly. So in that sense the situation isn’t so different.

Anyway indeed the turboR is a speed monster compared to the modest turbo of the MSX2+ computers. VGMPlay uses it to its advantage to improve the timing accuracy, allowing it to e.g. play back PCM in VGMs of Sega Megadrive games. But it’s also true that most software (especially games) doesn’t rely on turbo at all.

Van syn

Paragon (1975)

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25-06-2020, 21:46

out of curiousity, is it harmful for a panasonic to write to psg in turbo mode due to it being too fast?

Van Wild_Penguin

Hero (609)

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25-06-2020, 23:26

Getting way out of topic, by the way ;-). Necromutation!!!

I needed to test my PSG a little while ago (the project has been on hold because of lack of time/other duties). If I understood it correctly, the PSG gets it's frequency from the Z80 frequency (or the same XTAL?), which is divided by 2 to get the base frequency. In a turbo modification, the PSG is not written to more often, but the base frequency which the PSG uses to synthesize sound is different.

How often the PSG registers are written to depends on the program, and of course a turbo modded CPU can also change the registers more often. I have no idea if there is an upper limit to how often the PSG can be written to (or follow the changes without crapping out), but I would guess it will start to become an issue at much higher write rates (an order of magnitude higher) than what the Z80 (even turbo modded) can do. I believe this is the reason you can get a lot more nicer music/sound from the same chip on more powerful computers.

After all, it is a really "dumb" chip.