Minimig v1.1 ARM Hardfile Demonstration

[denli]

@bloodline

Perhaps you would be better of with an OpenPandora and UAE4ALL

The Minimig is an A500 cycle exact (nearly) device.

[wolfchild]

I'm curious about one little detail on the accelerated Minimig.

What speed-grade is the 68k used in the video?  It seems that the 16MHz part is the most easily available from Digikey, and that's what I got.  I'd be surprised to see it going all the way up to 28MHz!

Also, what 68k grade do the amigakit Minimigs ship with?

[whiteb]

68000's are HIGHLY overclockable, and they dont need heat sink's

The default 68000's in the Minimig's are 16Mhz clocked by the core to 7Mhz.

[boing4000]

Right, Dennis also told me some time ago that this SEC000 are very "overclock friendly" and even the 16MHz 68k should also work fine at 28Mhz.

[amazing]

hehe my only question is when will the board available...
i can not wait  

[yaqube]

The Minimig in the video is equipped with 20 MHz 68SEC000 (the price difference between 16 and 20 MHz version was marginal). The speed gain of the CPU run @ 28 MHz over standard A600 is only 2.91 due to memory running at 7 MHz and being shared with custom chips. I have also made some tests with memory run @ 14 MHz (requires faster memory chips) and achieved speed gain of 5.05.

I have made some tests to find out what the maximum operational frequency of the 68SEC000 rated at 20MHz is and mine is able to run at 39 MHz. But without equally fast memory access the speed gain is very small (SysInfo reports 3.03 times the A600 speed).

I do not expect the 16 MHz rated parts to be much slower.

[Darrin]

yaqube wrote:
The Minimig in the video is equipped with 20 MHz 68SEC000 (the price difference between 16 and 20 MHz version was marginal). The speed gain of the CPU run @ 28 MHz over standard A600 is only 2.91 due to memory running at 7 MHz and being shared with custom chips. I have also made some tests with memory run @ 14 MHz (requires faster memory chips) and achieved speed gain of 5.05.

I have made some tests to find out what the maximum operational frequency of the 68SEC000 rated at 20MHz is and mine is able to run at 39 MHz. But without equally fast memory access the speed gain is very small (SysInfo reports 3.03 times the A600 speed).

I do not expect the 16 MHz rated parts to be much slower.

So you don't foresee any problems with the 16MHz chip being run at 28 Mhz?

Are you planning a new core release for the unmodified v1.1 anytime soon (bug fixes, df1:, etc)?

[yaqube]

Darrin wrote:

So you don't foresee any problems with the 16MHz chip being run at 28 Mhz?

That's my expectation. Actual tests will reveal if it runs or not.

Are you planning a new core release for the unmodified v1.1 anytime soon (bug fixes, df1:, etc)?

Yep, I have already rewritten some parts to make the Minimig more cycle exact (it's not 100% exact and will never be) and now some games and demos work in the same way as run on a real Amiga.
But there are still some others that do not run correctly and I would like to find out why and fix the problems if feasible.

After implementing upgrades from SD-Card for the ARM controller board I will port the firmware to the PIC (most of it has been already done). The FPGA core will be the same for the ARM and the PIC (only the former will allow to have 4 floppy drives and hard disk support).

[Darrin]

yaqube wrote:

That's my expectation. Actual tests will reveal if it runs or not.

I'll let you know if my Minimig melts.  :-D

Yep, I have already rewritten some parts to make the Minimig more cycle exact (it's not 100% exact and will never be) and now some games and demos work in the same way as run on a real Amiga.
But there are still some others that do not run correctly and I would like to find out why and fix the problems if feasible.

After implementing upgrades from SD-Card for the ARM controller board I will port the firmware to the PIC (most of it has been already done). The FPGA core will be the same for the ARM and the PIC (only the former will allow to have 4 floppy drives and hard disk support).

Excellent news.  Cheers.  :-)

[Everblue]

Does it mean that on an unmodified 1.1, we will still get HDD support and multiple floppy drive emulation?

[Darrin]

Everblue wrote:
Does it mean that on an unmodified 1.1, we will still get HDD support and multiple floppy drive emulation?

No and yes, just the updated bug-fixed core with df0: and df1: support, but it will be "expansion board ready" should they become available.

[Everblue]

Ah cool. So the current minimig will be perfectly compatible (hardware-wise). This through a hardware upgrade and some soldering.

[Darrin]

Yep, that's the plan.  If I understand correctly, the new core will require a PIC update and provide the bug fixes, df1: support and probably the 28MHz CPU.

If you want the extra HD support and df2: and df3: then just replace the PIC with the ARM board.

If you want the extra RAM then you'll need to do (or have someone else do it) some soldering.

[Everblue]

1. 28MHz CPU - with the current CPU on board?

2. To replace PIC with armboard (for HD Support), it wont involve soldering right?

3. I would like to be able to install run WHDLoad - will that need extra RAM to be installed for all (working games) to er, work?

[yaqube]

Everblue wrote:
1. 28MHz CPU - with the current CPU on board?

Yep.

2. To replace PIC with armboard (for HD Support), it wont involve soldering right?

Basically no soldering. The ARM board is a plug-in replacement for the PIC. But unfortunately the original Minimig board design imposes a limitation on the maximum communication speed with an SD/MMC card. To overcome this problem you need to short two pads of two resistors (very simple soldering task). Otherwise the emulated hard disk transfer speed is limited to ca 200 KB/s.

3. I would like to be able to install run WHDLoad - will that need extra RAM to be installed for all (working games) to er, work?

I can't answer this question because I haven't done any such tests. I expect that with the base memory of 1.5 MB chip RAM those games which require 1MB of any or chip memory should run. But this is not confirmed.

[Everblue]

Thanks a lot!