Minimig hardware ideas

[mrmkl]

Since the "Minimig user feedback required" thread is specifically for feedback about the firmware for Minimig, I think a separate thread is appropriate.

A few things that were mentioned were 68030 CPU and Altera EP3C16 FPGA.

68060 CPU makes more sense, because it 3.3 volt device, so you don't need voltage translation devices in the between, like you would with 5 volt parts, such as 68030. The 68060 is extremely expensive as brand new part, but I think second hand parts can be had for much less.

The EP3C25 also is available in QFP-style packages (PQFP240 and EQFP144). They have little less I/O-pins than EP3C16, but more logic area, possibly for a softcore 68k CPU. For exterior IO, I/O expander chips (perhaps CPLDs, 5V tolerant)  could be used to transfer data serially using a few signal lines to/from the FPGA. Such as for the joystick/mouse ports.

[tonyyeb]

Isn't there compatibility issues with the 060?

[mrmkl]

tonyyeb wrote:
Isn't there compatibility issues with the 060?

Probably more than with 020/030 (040?)
How much compatibility could be achieved by using "de-grader" code, turning off cache's etc. when necessary? I've read that 060 doesn't work together with KS1.3.

[mrmkl]

About RAM: The original Minimig uses SRAM chips. DRAM would be cheaper, such as 3.3V SDRAM. If not too excited to design a complicated Synchronous-DRAM controller, also older EDO-DRAMs, 8MByte or even 16 MBYte in single chips can be found as "new old stock" parts.

[yaqube]

@mrmkl

Your ideas are almost exactly like mine. :-D

[tonyyeb]

mrmkl wrote:

tonyyeb wrote:
Isn't there compatibility issues with the 060?

Probably more than with 020/030 (040?)
How much compatibility could be achieved by using "de-grader" code, turning off cache's etc. when necessary? I've read that 060 doesn't work together with KS1.3.

I'm not sure. It is just stuff i've read etc... I would love an all singing all dancing super high performance Minimig. If it can be done and keep a good level of compatibility then bring it on!

[tonyyeb]

yaqube wrote:
@mrmkl

Your ideas are almost exactly like mine. :-D

So what is possible? What is achieveable? What would it take?

060, lots of memory, ethernet port, quick hardfile support (I don't see the point in adding an IDE controller)....

[Dwyloc]

As a owner of a real 060 Amiga A1200 tower I cant say I would want one in a Minimig.

1. The chip very large and would not fit in the existing form factor.

2. The 060 has the lowest compatibility of any 68K CPU for running Amiga games and software.

3. The chip is just far to expensive even second hand.

I think the best option is to ether emulate a fit an 020 or emulate an 030 from the point of view of speed and compatibility.

[FrenchShark]

Hello,

IMHO, we should have two designs :
- One with the Minimig form factor, a EP3C16 or EP3C25, a 24-bit VGA, SRAM or SDRAM and IDE/CF. I can easily adapt the custom HW I have already made for this.

- An A600/A1200 mainboard replacement with multiple FPGAs (2 or 3) to get enough I/Os for all the legacy ports, ethernet and USB. I have already started this project but I need some help. The first step is to get high resolution scans (at least 300 dpi) of A600 and A1200 mainboards, solder side only. I have done the scan of my A1200 board with a low cost flatbed scanner but the image is a little bit fuzzy. Why do we need that ? To get precise placement of the connectors, mounting holes. I use Gimp to do it : I set up the resolution to 300 dpi and use the measurement tool.

So guys, at your scanners ! :-P

Regards,

Frederic

[Lorraine]

/

[tonyyeb]

@Lorraine

I dont think the production cost would be much different between the systems. So why not make the best you can, that you do the most you can with? Then as more people buy it, it becomes cheaper to produce making it better for everyone.

[SKAN]

Lorraine wrote:
I can understand the need for hardfile support but I thought the whole point of MiniMig was its simplicity/to-the-point gaming nature (to play devil's advocate to the 060 talk) also isn't that higher-end stuff the NatAmi/Clone-A goals so a different market basically.

My point exactly. Minimig is cool as it is.
Once the current design is improved a bit (ARM daughterboard PIC replacement, f.i.) we have all we need (with a damn cool custom case too!)  :-D

[Belial6]

I would like to see an Ethernet port.  That way anything that is needed beyond the basics can be hung off the network, or emulated to run on the server.

[yssing]

I would like to see an 020/030 @ > 40

Also some build in RAM, 32 megs or similar would be more than enough. Personally I would not like to have to add EDO.

The same form factor as the A600/A1200 Mobo would be lovely.. I would get a MiniMig ASAP if it could be made to fit inside an A600/A1200 casing (with out to much hassel for the end user)

It would be nice to have it emulate AGA, but not neccessary (spelling?)

Harddrive support is almost "a must have"