New Minimig cores available

[yaqube]

@asymetrix

Superfrog works perfectly, it was the game I most frequently tested. I think you know why  :-D

And it was a pain in the a** to get it working correctly, usage of sprites in this game is really weird (and very similar to other Team17 games) and doesn't conform to description in the AHRM.

There was also an issue with horizontal overscan: when right display window border was set very close to its limit the normally invisible part of the horizontal display window wasn't hidden at all. Project X also had similar problem.

[yaqube]

@boing4000

I used Xilinx ISE 9.2i and haven't upgraded yet not to risk compatibility problems. In a few weeks I will upgrade and check why it doesn't compile.

[yaqube]

@Loriano

Take a look at http://www.amiga.org/forums/showthread.php?t=37983

At best you can have 512 files in the root directory (all must have 8.3 compliant names, no subdirs, no volume name). You need two files for the FPGA core and the Kickstart. So 510 is left for ADF's.

Cheers,

[yaqube]

@everblue

1. Minimig outputs scandoubled video signal at 50Hz/31kHz in PAL and 60Hz/31kHz in NTSC. Most monitors detect this signal as 800x600 SVGA mode for PAL and 800x600 VGA mode for NTSC.

To be able to display scandoubled PAL video mode the monitor must be able to sync to 50Hz vertical frequency (most monitors cannot). I use EIZO monitors and they can sync.

There is also one important thing: to be able to see the Minimig display without horizontal scaling distortions (blured vertical bars or different width of the same letter displayed in different parts of the screen) the monitor must be able to set its sampling clock to 910 pixels per line. Only my old Eizo L568 can do this but the newer one (S1931) can't (956 is the low limit for the SVGA mode).

2. Scrolling is always smooth.

3. When you buy a new Minimig its PIC is preinstalled but I wouldn't expect it to have the current firmware release. You can always upgrade with null modem serial cable.

[yaqube]

@Everblue

According to Samsung Syncmaster 151s specs this monitor can sync from 50 to 75 Hz so you will be able to display scan doubled PAL mode on it. The scrolling will be smooth and games will run with normal speed.

[yaqube]

@Sascha

All timing constraints were met? If not try to set synthesis optimization for maximum speed and higher fitter effort.

[yaqube]

@Sascha

As I can remember in Dennis's original code the 14 MHz clock was only used to generate 7 MHz clock. Nothing more. As I used another DCM to directly generate 7 MHz clock in phase with 28 MHz clock there was no need to have 14 MHz clock any longer.

Running the CPU with 14MHz clock without proper bus timing is a hack which is not guaranteed to work reliably.

In the future I will rewrite CPU bus interface and make it working with 7, 14, 21 and 28 MHz clock selectable from the OSD menu. Many programs have software delay loops and will have troubles running on faster CPU.

[yaqube]

@Belial6

I have simpler solution than two PIC's: one ARM MCU. Cheaper, faster, better.  :-D



The design is in hardware verification stage. The first program which blinks the disk led has been run successfully. As I don't have almost any time now the project is advancing very slowly.

[yaqube]

@Darrin

It is what you think it is. :-D  It should fit into Loriano's enclosure without any problem. I don't know if an additional hole for the USB socket will be necessary as firmware upgrades can be done from the SD card.

@Norway

When the firmware is finished this adapter will function as a hard disk emulator and will support up to 4 floppy drives. Maybe some additional disk image formats to the ADF type will also be supported.

[yaqube]

Initially the USB port will be used for firmware upgrades. Maybe later it will be used for accessing the SD card from a PC (will act as a flash card reader - solution similar to the PSP's one).

This is only USB full speed (1.1) device port so you can only connect it to a PC.

More info will be available when it is done.

[yaqube]

@Sascha

In Minimig1.v file at line 168 there is an NTSC parameter definition. Change it to "1" and your builts will default to the NTSC screen mode.

Also read comments in BootRom.v file and change FPGA version id to identify your releases.

[yaqube]

@whiteb

The height of the adapter board is 5.75 mm without pin header. I have used low profile pin header which is 1.85 mm high but can't find a supplier of them.
If the clearance is a constraint it would be possible to remove plastic base of the pin header and have the adapter board sticking out only 6 mm above PIC socket.

The support for two floppy drives should be possible using current PIC MCU.

[yaqube]

We must be aware that the 68HC000 used in SupraTurbo28 wasn't manufactured in faster speed grade than 16.67 MHz and was clocked at 28 MHz.
I'm curious what is the limit for 20 MHz 68SEC000.