How is that possible? | MSX Resource Center (Page 2/4)

By erpirao

Paragon (1264)

01-11-2020, 17:51

new uptade, msx2+ to turboR!!
imitating the turboR
Imitating the turboR

By Randam

Paragon (1430)

01-11-2020, 19:25

oh wow... Will it also work for a turboR: speeding up a turbo R? I really want one!!!

By erpirao

Paragon (1264)

01-11-2020, 20:40

I think it does not accelerate the turboR, although perhaps the z80 @ 20mhz is somewhat faster than the r800 in certain functions.
but it does open up the possibility (which I had already ruled out) of a possible external accelerator for MSX, in the z380 style.

By Randam

Paragon (1430)

01-11-2020, 21:23

so it wouldn't be possible to use it as a coprcessor next to processor in the turbo r? If that's true it is a pity

By PingPong

Prophet (3898)

01-11-2020, 23:41

If i understand correctly, let say that the high speed z80 is executing a OTIR. What happens?
a) the high speed z80 is paused
b) the low speed (original, on board z80 @3.5Mhz) z80 see on his data bus a sequence of instructions:
LD A, byte to emit
OUT (I/O PORT),A

Is this correct?

if this is correct the speed should be a little faster because on original z80 an otir takes 23 states and the on the proxed one it takes
LD a, immediate -> 8 states
out (I/O),a -> 12 states
so a total of 20 States.

By Robotarm-Johnny

Supporter (2)

05-11-2020, 14:24

¡Hi! If I am not mistaken, this cartridge would turn any MSX2+ machine (or at least the Panasonic FS-A1WSX one ) into a FS-A1ST fully compatible TurboR! is that right?

What I wanted to ask is, does anybody here know If this cartridge is going commercial?? (Soon? ). I think that this expansion is a huge improve!

By Pencioner

Scribe (1502)

05-11-2020, 14:47

No, it is not clear yet, currently the R800 multiplication is not implemented so might be incomplete compatibility btw

By sdsnatcher73

Prophet (3388)

05-11-2020, 14:49

This seems to indicate the z80 is implemented in FPGA otherwise how could we add the missing R800 op codes?

By jltursan

Prophet (2619)

05-11-2020, 15:10

Nope, it's using real Z80 & Z280, or am I wrong?. Maybe he's trying to translate the R800 opcodes to Z280 ones, this CPU also have hardware multiplication instructions.

By Pencioner

Scribe (1502)

05-11-2020, 15:48

It has 280 on the board but the CPU switching is not implemented if i understood correctly, thus, at the moment it uses the Z80 at 20MHz which performs same as R800. I hope that full R800 compatibility could be achieved of course, though