FPGA Replay Board

[yaqube]

Mike, do not forget that FAT filesystem has ~4GB limit on file size. Please also remember that Amiga OS 3.1 scsi.device do not support drives larger than 4GB and fastfilesystem doesn't handle well partitions larger than 2GB.

I'll buy a bigger SD card and try it as well with the new firmware.
I'm running a different filesystem so it will be a good test.
/MikeJ

[yaqube]

Quite right, even though the filesystem supports fat32 the Amiga os may be an issue.

The FAT32 has also 4GB file size limit.

[yaqube]

On your daughterboard design, will teh card reader on theer have teh same limitations?  Would it be possible to use use 2 x 4GB HDF files via the FPGA card reader and anotehr 2 x 4GB HDF files on the daughterboard card read to have 4 x 4GB "hard drives" available to Workbench?

No, the daughterboard card reader is visible as Amiga hard drive and not as hard file emulator. You can format it with whatever filesystem you like. The limitations are imposed by filesystem handler you use.

Using the daughterboard USB, would it be possible to mount a large (>4GB) external USB hard drive using SFS or PFS3?

Yes, USB host controller uses Poseidon USB stack so it is the limiting factor.

[yaqube]

Excellent.  So in theory I could put in a 20GB card and format it as a single 20GB PFS3 drive or a 2GB FFS and a 18GB PFS3, etc?

Yes. But there are FFS versions which support partitions larger than 2GB (OS3.5 or 3.9) so you could have one 32GB FFS partition.

Meanwhile HDF files on the main FPGA board's card reader will still be available to mount?

Of course.

Excellent.  Having used Poseidon for several years now, it is a great stack and I'm glad we'll have it on the FPGA Arcade.  The expansions options it will add will be almost limitless.

Exactly. I wonder if dedicated micro SD card reader is necessary because an USB micro SD card reader connected to daughterboard USB port reaches transfers over 13MB/s.

[yaqube]

Is the FPGA chip in the FPGA Replay fast enough to generate a 1280x1024x32bit @ 60fps display?

Yes, the FPGA is capable of it. Moreover the memory bandwidth is more than enough to display such resolution.

Does it already do that?

Currently Minimig AGA core with RTG module (Picasso96 compatible drivers are available) can display resolutions up to 1920x1080 but only in 8-bit colour depth. Maximum resolution in 32-bit mode is 800x600.

Or is it something you could try to squeeze in with some hardcore optimized code magic?

There are plans to improve memory controller to allow more bandwidth and more colours in higher resolutions - current limitation is a consequence of original Amiga Chip RAM design (the RTG module fetches its display data from Chip RAM).

What is the theoretical maximum bandwidth of your memory chips?

166MHz x 2 x 16 bits = 666MB/s

How much actual bandwidth are you actually able to get out of the system so far?

My design has two independent logical memory channels to SDRAM each capable of 113 MB/s. One channel is used by the custom chips, CPU, AHI DMA sound channels and RTG board blitter. The second channel is dedicated to memory refresh and RTG display.

I am asking these questions because I want to write a game that maxes out your hardware.  And I think that I will be stuck using 640x512x32-bit mode.

Such resolution is problematic with VGA monitors. But my RTG module supports scan doubling to upscale 640x512 to 1280x1024 which is SXGA native resolution.

[yaqube]

Ok so it sounds like we can have up to 64MB of chipram and use the daughterboard for 128MB fastram.

Can the RTG RAM share the chipram?  Or not?

As I've said once before our DDR memory controller is dual ported. One port is connected to the AGA chipset and the CPU while the other one is used exclusively by the RTG display module. It means the CPU can write to RTG memory with the same speed regardless of display mode.

The RTG RAM is allocated by our Picasso96 driver from CHIP RAM pool. So if we want to have 8MB graphics card we need to allocate 8MB of CHIP RAM. If we want 32MB RTG buffer we need to allocate 32MB of CHIP RAM.

Like could we have 64MB chipram + 64MB RTG ram using the same block of RAM on the mainboard?

No, because it's the same physical memory. In fact we can have maximum 50MB of CHIP RAM (2MB standard + 48MB extra). The rest of 64MB is used by ROM, SLOW and Z2 FAST RAM.

I am just trying to work out what the capabilities are.
If they can't share the same mem then when I write my RTG game for Replay I would prob say "If u have the 060 daughterboard: Set ur chipram to 4MB and your RTG RAM to 60MB"

Right now the Picasso96 driver decides how much RAM it wants to use so if you want to use RTG you should set the CHIP RAM config to maximum.

I am also curious as to how fast the 060 can copy data from its 128MB bank of fastram to the mainboard RAM.

The actual speed depends heavily on chipset activity. The CPU can write to the CHIP RAM as fast as 28 MB/s. With all DMA channels active (excluding the blitter) the speed drops to 14 MB/s. The RTG display uses another memory access port so no matter what the RTG display mode is the CPU can write to the RTG memory always with maximum speed.

Its makes a giant difference as to what I can do with Animation.  When the Natami work evaporated, it was really really slooow to copy from fastram to chipram with the CPU.  That part of the memory controller had not been optimized in any way.  So I am curious if ur memory controller suffers the same limitation/flaw.

Our memory controller can be optimized further. Right now it's faster than any other Amiga chipset.

My CPU blitting routines are over 140x faster than the AGA blitter on Real AGA Amigas.  But that only works if the CPU can copy data from Fastram to Chipram in a reasonable manner.  If you have a great memory controller then my routines will go even faster on Replay.  But if your memory controller is crippled then my speed could drop to 10x blitter speed which would be really completely useless for my hires hispeed animated gamez.

Our CHIP RAM controller is two times faster than in the fastest Amiga. It means the blitter can move data at least twice as fast. The difference is higher when more bitplanes are displayed.

For compatibility reasons the AGA blitter is 16-bit like its real counterpart. But I have implemented another 32-bit blitter to accelerate RTG operations. It's much faster.

[yaqube]

I've merged in the latest changes (mainly audio fix)

Mike, what was the problem with audio?

[yaqube]

but the daughterboard comes with local memory, doesnt it?

Yes, it does. There is 128 MB of SDRAM on the daughterboard.

[yaqube]

Well, I've already been told that there will be a serial port compatible with MIDI interfaces a few pages back in this thread (I assume original Amiga MIDI interfaces, I didn't get an answer when I asked that)

The serial port is compatible with Amiga baudrates including the one used by MIDI. Since our board is very small there was no place to put an old-fasion 25-pin serial port connector. We have just put its 9-pin counterpart.
So you cannot connect directly your old MIDI interface, you need to change plugs.

There is another drawback, the 9-pin connector doesn't carry +/-12 Volt power. If your MIDI interface needs it, it should be sourced externally.
When the daughterboard is ready we will think about making a dedicated MIDI interface for our board so your life will be easier.

[yaqube]

Second video was good, but I'd like to see some Amiga stuff running on the 060 daughterboard.

What kind of stuff do you want to see? Just tell us and we will see what we can do.

I'd really love to see a benchmark utility compare the AGA '020 core with the '060 daughterboard (and both to a regular A4000/040).

There was published a screenshot of SysInfo running on my board with TG68K core at 28.36 MHz with data and instruction caches. The performance is comparable with 030@50MHz.

[yaqube]

I have made some tests using bustest and my A4000 and both of my Replay boards (Rev.A with daughterboard and standard Rev.B). What do you think?

Code: [Select]


BusSpeedTest 0.19 (mlelstv)   Buffer:     262144 Bytes, Alignment: 32768
memtype op A4K PAL A4K VGA A4K RTG RP PAL RP VGA 060 PAL 060 VGA 060 RTG
fast readw 33.7 33.6 33.7 20.9 19.4 52.9 52.3 52.8
fast readl 39.6 39.2 39.5 28.4 28.2 60.2 60.5 60.3
fast readm 39.5 39.6 39.4 29.3 29.2 60.7 60.7 59.7
fast writew 27.7 27.4 27.6 5.8 4.7 49.3 48.8 49.0
fast writel 27.5 27.6 27.6 7.7 6.2 48.6 49.1 48.6
fast writem 27.6 27.7 27.5 10.9 8.3 49.3 48.9 48.7
chip readw 1.7 0.7 2.3 5.8 4.7 7.1 7.1 7.1
chip readl 3.4 1.4 4.7 7.7 6.2 14.1 14.1 14.1
chip readm 3.4 1.4 4.7 10.9 8.3 14.1 14.1 14.1
chip writew 2.4 1.1 3.5 5.8 4.7 11.7 8.9 14.0
chip writel 4.8 2.2 7.0 7.7 6.2 23.1 17.7 27.9
chip writem 4.8 2.2 7.0 10.9 8.3 23.1 17.9 27.9
rom readw 33.5 33.7 33.7 20.9 19.4 52.6 52.9 52.5
rom readl 39.5 39.4 39.4 28.4 28.2 60.0 60.1 60.5
rom readm 39.3 39.2 39.0 29.3 29.2 60.7 60.3 60.5

A4K - A4000 w/ CS MKII 060 60MHz + 128MB 60ns DRAM + Picasso IV
RP - Replay w/ Minimig AGA core + TG68K 28MHz dcache/icache + 8MB FAST RAM
060 - Replay w/ Minimig AGA/RTG core + Rev.6 68060 106MHz + 128MB 53MHz SDRAM
PAL - 640x512x256 (PAL High Res Laced)
VGA - 640x480x256 (Productivity)
RTG - 1024x768x256

[yaqube]

I noticed you listed VGA mode times.  Is that the way to get flickerfree AGA gfx on a replay?  To use DoublePAL, DoubleNTSC or VGA modes?

Yes, all programmable modes like DoublePal, DoubleNTSC, Multiscan etc are supported.

[yaqube]

I meant is that the only way to get a flickerfree interlaced AGA display?

I don't have any plans to implement a flicker-fixer. Productivity and DoublePAL/NTSC modes are much faster on Replay than on any AGA Amiga (over 8 times) so it's not a problem. Besides you have a bunch of nice RTG screen modes so why not use them?

[yaqube]

How much Mhz can I get with a full MMU?  Is it possible to achieve 80Mhz with MMU?

My rev.6 CPU works at 106 MHz with fully functional MMU and FPU. With disabled MMU it works at 120 MHz.

[yaqube]

While a fan of the current board form factor... would you also consider a different layout of the board that contains the current FPGA Arcade and the '060 board?

I can tell you in secret that I'm working on a new board which integrates an FPGA and 060 CPU together with other goodies. It won't be a direct replacement of any existing Amiga mainboard.

[yaqube]

Does the 060 daughterboard come with CPU, or without ?

It depends. Mike is trying to get some from China but so far all of them have turned out to be fakes.

is it possible in the future any solution between the Natami's 68050 and your daughterboard ?
(because the stock of rev6-060 not too much, and supply comes with lot of risks)

Yes, there are plans to create another daughterboard with a bigger FPGA which could act as high-performance CPU. The question remains: who will make the CPU core?

Did you use any cooling solution for 060 at 106 Mhz

Yes, small heatsink and small fan. At 100 MHz the CPU is able to run without active cooling.