True 16MHz Mode

[Icky]

Exxos and I have been discussing boosting the STF Remake. In his grand plan the remake is designed so that we can run the ST in what I like to call the True 16MHz Mode.

A lot of the boosters out there are limited to boosting the CPU and ROM only as there are limitations on the RAM etc on the ST motherboard.

The STF Remake has been designed so that we can actually boost the CPU, ROM, RAM and Blitter together. Working with exxos I have managed to get my STF Remake to operate in this mode with only two 74LS chips I had lying around.

So currently my STF Remake has the following:

Boosted - CPU (16MHz), ROM (16MHz), RAM (16MHz) and Blitter (16MHz)
Stock - MFP (4MHz), GLUE (8MHz), 1772 (8MHz) and DMA (8MHz)

Running GEMBench, with the Blitter disabled, against a stock STFM score its rocking pretty much 200% across the board, hence the True 16MHz Mode term.

IMG_3800.jpg

Now this is where things start to get interesting as turning on the Blitter, which is also in 16MHz mode, which AFAIK is the only one running at that speed currently on the planet. We get some interesting benchmarks which blow a lot of the scores away in the benchmark section in the forum for boosted STFM.

Overall = 283% and look at that Blitter score of 1141%

IMG_3801.jpg

:bravo: exxos on your grand plan coming to fruition. Roll on the 50MHz STF Remake :twisted:

All you STF Remaker's out there instructions will follow soon on how you too can get your ALPHA boards into this mode.

[rpineau]

That is truly brilliant.
:thanksyellow: :bravo: :cheers:

[exxos]

:cheer: :cheer: :cheer: :cheer: :cheer: :cheer: :cheer:

Yeah, once the FPGA cores are sorted out, next step will / should be, a 32MHz system 8-)

What we need now is a new shifter which can make use of the extra bandwidth ;)

[PaulJ]

Thats pretty impressive guys.. :dualthumbup: :dualthumbup: :goodpost: :bravo:

[exxos]

ST-RAM running at double speed was the bottleneck in my boosters as only the CPU and ROM could run at 16MHz. This is why. https://www.exxosforum.co.uk/forum/viewt ... f=42&t=567 previous boosters only gave about 50% boost overall. But they couldn't do much for games as games mostly are copying blocks of RAM about for sprites etc. So the boosters gave a boost mostly in 3D games as they made use of the higher CPU speeds with integer division etc.Though now with the current setup, all games should run at double speed now. Games which use the blitter should rocket along.

As said before, if we can get the FPGA MMU working , then we can have the full 14mb ram all running at 32mhz. That will give a system 4x faster than a stock ST. With this setup, there is no need for altram as all ram will be ST-RAM. We are a long way off getting that running. But I hope to include this current 16mhz mod into the next remake board.

Also this mod isn't finished. We need to be able to switch back to the stock 8mhz mode somehow yet. So a PLD will be needed. It might be possible to get 32mhz CPU working, but I am skeptical because of the issues I had with the sec booster as glue is a bit crappy so 32mhz boost may not be possible until the sec booster is finished. I need to get a few test boards done, and there will be up for beta testing in a few weeks time.

[rubber_jonnie]

That is damn impressive, especially that Blitter benchmark.

Well done guys, and all the incentive I need to get mine running finally.

[PhilC]

Well done!! Mine is all up and running except for a video problem, seems like I have more than just the missing Vsync line, so it's been put on the back burner with so many other projects.

[PaulJ]

Been looking for an excuse to pull the Exxos Atari off the shelf.. :) :) :) Any chance you can post the mods.. :?: :?: :?:

[PaulJ]

One question.. does the stock dynamic dynamic controller ram run at double the speed? Is this with the same atari dram controller? :WTF: :WTF:

[exxos]

Been looking for an excuse to pull the Exxos Atari off the shelf.. :) :) :) Any chance you can post the mods.. :?: :?: :?:

Icky will do once we verify some things... ( and have time)

One question.. does the stock dynamic dynamic controller ram run at double the speed? Is this with the same atari dram controller?

We are overclocking the MMU... by default it runs from the 16MHz clock, but we are pushing it with 32MHz.. so RAM runs at double speed (Which is one reason I went for the Falcon RAM board as I knew it would work at the higher speed)... But there is a lot of patching to all the clocks on the motherboard, as we cannot overclocked the sound system for example, otherwise the sound would play twice as fast :lol:

This is also why I developed the SMT GLUE & MMU boards... as those chips are likely the last production run of those chips, so stand the best chance of overclocking over the earlier PLCC chips.... this does not mean All the PLCC chips can't be overclocked, not enough testing has been done to prove this either way. But I made provisions early on this with the SMT adapter boards..