I'm going to take some pictures. Where should I post them? Here, or in another thread?
Just upload right here or perhaps in the Minimig General Discussion
forum and a new topic like "Info & picture of ported Minimig"(?) would be ok.
Finally I have taken some pictures. Sorry for the very poor quality, I used the cellphone camera, and I'm not a very good photographer =).
As you can see, the board is not very clean (I did not have too much Isopropyl alcohol left to clean it) and it has several patches due to design mistakes.
I designed and built it about two years ago and it was conceived as a "portable" minimig (I named it PalMig =)). The keyboard PCB is still missing because it's boring and I did not have time to design it =). At the moment I'm using an external PS2 keyboard.
The blue PCB is the actual PalMig, the green board is the expansion.
The bottom side:
You can find the 34-pin connector (I put it for ease of debug of the video FPGA and in case I needed to connect different LCD panels), the power on button, the power jack, the S-video, the composite out, the VGA out, a hole for a missing joystick port (unfortunately I made a mistake on the DB-9 port package and I placed them too close... so there was no space for two joystick ports), the audio jack, the mouse and keyboard PS2, the SD holder, the USB connector and the RS232 connector.
Above the 34-pin connector there is the battery holder. The two PCB-to-PCB connectors are for the CPU and memory expansion, respectively. I also put a 4-MBytes SPI Flash memory, to store the FPGA bitstreams and some kickstarts.
The top side:
You may find: the video FPGA (left), the chipset FPGA (right), the 68SEC000 (unfortunately, when I placed the orders at Mouser and Digikey two years ago, the 16MHz version was out of stock. The 10MHz version cannot run at 49.x MHz, but it runs error-free at least up to 28MHz, and with the latest Yaqube's core, it reaches 2.9 Mips@28MHz) and, the AD724. On the right you find the I2S audio DAC with Amiga's original Sallen Key audio filters (which are bypassed when the power LED is off), and a power amplifier (for the headphones or 350mW speakers, which are still not connected). The I2S audio DAC also allows to select the volume (simply using a left or right shift of the audio samples).
On the bottom, there is the keyboard connector and next to it the LPC2368 microcontroller. Unfortuately, the LPC2387 was not stocked, so I had to purchase the 2368 (which has fewer RAM and it lacks the USB host controller - so the USB port is non-operational at the moment).
There is also a MAX1500 battery charger.
The video FPGA acts simply as a LCD controller with flicker fixer and it has 1MB of static ram as framebuffer.
The expansion board consists of two static ram chips, a 16MB 166MHz SDRAM (the 32MB version is not stocked at Digikey. I used the Winbond SDRAM because they are low-power compared to Micron or ISSI. Nonetheless, the signals are routed to support up-to 32MB) and the 500kgates Spartan3E FPGA. At the moment the SDRAM controller is not implemented yet (first I have to get the tg68 working)
I did not use a single 1200-1600kgates Spartan 3E for the whole system because it needed a 6-layer board with fine pitch track/space, which was too expensive.