32GB SD, 4MB S-RAM, ARM Controller, FastSPI mod, Audio Mod
PCB top
Transparent OSD
Optional ARM controller
Joyports
In crystal case
Hi Res version, PCB top
- 2048 x 1536, 1,273K
Hi Res version, Transparent OSD
- 2592 x 1944, 2,035K
Hi Res version, Joyports
- 1024 x 768, 107K

Minimig V1:
Processor: 68SEC000
Clocked at 7.09Mhz (Normal) or 49.63MHz (Turbo) mode. Additionally at Turbo mode a direct mapped write-through unified 4kb cpu cache inside the FPGA is active and speed-up the intefer performance similar to a 68030@25MHz. Blitter is faster to let vector based program speed-up a lot

MMU: None

FPU: None

System Control: OSD (On Screen Display) menu

Chipset: OSD selectable

  • OCS-A500 - act as the Amiga500/2000 8370/8371 Fat Agnus with normal 8362 Denise (most common mode)
  • OCS-A1000 - act as the Amiga1000 8361/8367 DIP Agnus including its internal characteristics, also simulate very first "Daphne" Denise without EHB reduction
  • ECS - act as 8372/8375 Fat Agnus including the SHires 8373 Denise

At all settings the full 2.0MB of Chipmem is available

Audio: Paula 8364 implementation
Known 4-channel stereo output, without the Audio-Filter as in real Amiga model (no low-pass filter)

Kickstarts: OSD selectable
V0.9, V1.0, V1.1, V1.2, V1.3, V1.4, V2.04, V2.05, V3.0 (for A1200), V3.1 (for A500/600/2000)
As .ROM image file on sd-card root. All version always take 0.5MB of S-RAM

Bus Controller: FPGA

Expansion Slots: None

Standard CHIP RAM: OSD selectable
0.5MB, 1.0MB, 1.5MB, 2.0MB
Note: full memory usage only is possible at 4.0MB board!

Slow/Ranger RAM: OSD selectable
None, 0.5MB, 1.0MB, 1.5MB
Note: full memory usage only is possible at 4.0MB board!

RAM sockets: None
piggy-back soldering to get 4.0MB of raw memory

Expansion: Action Replay MK-III
Available as AR3.ROM at sd-card toot, load via bootloader if set enabled in OSD (freez button: R-CTRL+BREAK keys)
AR3 will take 0.5MB of S-RAM to work

Hard Drive Controllers: PIC/ARM
FPGA simulate an A600 style GAYLE chip
Provided via sd-card .HDF in sd-card root

Floppy Drives: OSD selectable
DF0 up to DF3 (feed with .ADF image), can work at normal and fast speed

Drive Bays: None

Expansion Ports:
1 x 9pin VGA like analog RGB output
1 x PS/2 Keyboard
1 x PS/2 Mouse
1 x SD/MMC card slot (up to 32GB SD/HC)
2 x 9pin Joystick
1 x 9pin Serial
1 x 3mm Stereo Audio Jack (like PC soundcard)

Motherboard Revisions:

  • Rev 1.0 with SPI wire fix
  • Rev 1.1 regular available

Minimig is developed by Dennis van Weeren, freely available unter the GNU public license V3 and can be ported, altered or expanded as long as the sources will be published as well.
The whole system grow in time and may also break several limits (such as the 2.0MB Chipmem limit of real Amiga chipsets).

Minimig in general is the Verilog FPGA source code with the C sources for PIC or ARM controler.
Basically any FPGA based board with required chip capacity and availabe io-pin is able to host a synthesized Minimig core-
For each different board an individual FPGA core must be synthesized to make use of it.

The OSD act as preferences or "GUI" to setup the system for any kind of requirement via keyboard or joystick.
Some software need special memory, CPU speed, Kickstart or Floppy drive settings to work properly. Memory and Kickstart settings require an Amiga-reset to get active.
Chipset and CPU frequence selection take affect directly on the fly, same as the additional Video filter and Scanline simulation.

Video is 12Bit analog RGB (max. 4096 colors) and provide original 15KHz PAL/NTSC or 31KHz double-scan (not flicker-fixed) VGA 50/60Hz output, selectable via a jumper on the Minimig board.
Vision is native/smooth as any real Amiga model. There is no frame skip as known from software emulation.

PIC/ARM is a permanent programed micro controller (MCU) and need to be flashed with a compiled firmware file.
FPGA always is empty without power and will be programed via MCU at bootup. The FPGA core file has to be named "Minimig1.bin" at sd-card root.
 

Possible mods:

  • FastSPI mod, bridge between R50 & R51: speed-up sd-card data transfer a lot if its set active in ARM firmware via OSD. Without the modification the FastSPI mode MUST NOT be active! It will lead to data damage!
  • Audio mod, remove R15: will 100% separate both Amiga audio channel like in any real Amiga model. With R15 in place the left and right channels are slightly mixed together. Most likely done to get a more smooth stereo output, but it also makes sound output a bit lower.

 

Page contributors: boing4000
Updated: 3/8/2013 . Added: 3/4/2013