The bill-of-materials for both the rev1.0 and rev1.1 is available for download in the download section. The BOM is pretty generic so I have listed the critical parts in the table below with some more information and possible sources.
|XC3S400-4PQ208||The Spartan-3 FGPA||NuHorizons, Digikey (XC3S400-4PQ208C-ND)|
|SD_CARD||MMC flash card push-push connector||Farnell (9186212)|
|DC_CON||2.1mm DC power connector (DC10A)||Farnell (224959, 10 per package)|
|3.5MM_CON_PCB||3.5mm stereo jack||Farnell (152204)|
|DSUBH_9M||serial and joystick connectors||Farnell (1099289)|
|PS2_CON||PS2 keyboard/mouse connectors||Farnell (1200113)|
|SP3232EUCN||SO16 3.3V/0.1uF RS232 transceiver||I used this one from Sipex, Farnell (9386955) but any compatible 3.3V/0.1uF chip will do|
|MC68SEC000FU20||processor, 10MHz or more||currently available at Digikey (MC68SEC000AA16-ND)|
|M68AW512M||sram, at least 70ns, 44-TSOPII||suitable replacement at Digikey (706-1048-ND)|
|PIC18LF252I/SP||microcontroller 3.3V DIP + socket||Digikey, Farnell|
|LM1117MP-ADJ||adjustable power regulator||Digikey, Farnell(9778187)|
|LED0805||red, green and blue 0805 leds||Farnell (8529884, 8529906, 8529949)|
|CT_100U/6.3V||Tantalum B-case, ESR=0.07Ohm||Farnell (1135233)|
The only part that needs programming is the PIC microcontroller. The FPGA is configured upon startup by the PIC. This means that you do not need any JTAG cables or special tools to program a Minimig. You only need a pre-programmed PIC18LF252 microcontroller. Programmers for PIC microcontrollers are cheap and widely available, both as diy projects or as commercial programmers. I use the PICkit-2 programmer.
The PIC ship itself is a DIL component that is plugged into a socket and not soldered in as in a in-ciruit-programming setup. This is for good reason; PIC controllers can only be bulk-erased when operated at 5V. The Minimig operates at 3.3V so you would never be able to completely "reset" the PIC when something went wrong during in-circuit programming. Thanks to the socket the PIC can always be taken out and inserted in a programmer for reprogramming when it is needed.
Although the PIC can be directly programmed with the necessary firmware, I strongly suggest the use of a bootloader. A bootlader makes it possible to reprogram the PIC through the serial port. To serial select jumper is designed to facilitate this. By setting the jumper to "MCU", a null-modem cable can be used to connect the Minimig to a PC. This way, new firmware can be downloaded without removing the PIC from the Minimig board. I use the Tiny PIC Bootloader by Claudiu Chiculita. This bootloader is easy to use and works reliably. Please follow the link on the links page to download the bootloader. When you use this bootloader (and you should!) program the file called "tinybld_18F252_20MHz.HEX" (inluded in the Tiny PIC Bootloader archive) into the PIC using a programmer. Then use the Tiny PIC Bootloader download tool to download the Minimig firmware into the PIC. This will make future updates much easier.
Although it is generally recommended to solder all difficult parts (like the FPGA, RAM chips and 68000) first, I would like to advise another order of building the Minimig. This alternative order of building will allow the builder to test a sub-section of the board before soldering the expensive components like the FPGA.
One of the most important parts of the board is the power supply system. So, we are going to build this part first by soldering the following components:
All 10nF capacitors:
C5,C6,C7,C8,C16,C18,C19,C21,C22,C25,C28,C29,C30,C35,C36,C39,C40,C43,C44,C46,C52 and C55.
All 100nF capacitors:
C3,C10,C11,C12,C13,C20,C23,C24,C26,C31,C32,C33,C34,C38,C41,C42,C45,C50,C53,C54 and C56 (note that C10,C11,C12 and C13 are not strictly part of the power supply system but it's better to solder them now than to forget them later).
All tantalum capcitors: (NOTE: the marker on tantalum capacitors indicate the POSITIVE terminal! Please observe correct polarity, tantalum capacitors WILL burn...)
C4,C17,C27 and C37.
IC1,IC3 and IC4.
Resistors and leds:
R37,R38,R42,R14,R26,R28,R2 and D1.
Electrolytic capacitors and the power plug: (NOTE: the marker on electrolytic capacitors indicate the NEGATIVE terminal)
C14,C9 and J2 (C15 is better not placed at this stage, see below).
|Voltage at J6, pin 7||+5V +/-5%|
|Voltage at J10, pin 7||+5V +/-5%|
|Voltage at J5, pin 4||+5V +/-5%|
|Voltage at J8, pin 4||+5V +/-5%|
|Voltage at tab of regulator IC1||+3.2V to +3.4V|
|Voltage at tab of regulator IC3||+1.20 to +1.26V|
|Voltage at tab of regulator IC4||+2.40 to +2.6V|
Only if all of these voltages check alright you can proceed by soldering the big chips IC5, IC6, IC7 and IC9. Because all SMD parts at the bottom side of the PCB are now soldered, you cannot lay the board flat anymore. Therefore, give the PCB some "feet" before soldering the big chips. After that solder the remaining SMD parts and finally solder all trough-hole components. The PCB is now done!