Minimig v1.1 Alternate parts

[nBit7]

A number of the parts on the minimig can be substituted with functionally and physically equivalent (or in some cases better) parts.

It appears that there are a number of people trying to put Minimigs together but lack the expertise to find and choose suitable alternative parts.

I was thinking of starting a BOM (list of parts) and guide of suitable parts and where to get them.  Would this be useful?
If so is there already a site where this information could go?

[hifibonsai]

Yes, definitely...  :-)
For example does anyone have any idea if:

http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=122-1520-ND

is compatible (no changes to the rev1.1 pcb) with 122-1519-ND?
If it is just a matter of recompiling the core and maybe adjust it a little bit it might actually be a better substitute (more gates)...

[mrmkl]

I'm afraid not.
Usually the FPGA manufacturers change the pinouts for each FPGA-family. (Such as Spartan -> S2 -> S2E -> S3 -> S3E)
IIRC, if both PQFP-208 parts are compared with each other, 500E Spartan also has more input-only type "IO":s, and the XC3S400 has more INPUT/OUTPUT IO:s.

[amigadave]

nBit7 wrote:
A number of the parts on the minimig can be substituted with functionally and physically equivalent (or in some cases better) parts.

It appears that there are a number of people trying to put Minimigs together but lack the expertise to find and choose suitable alternative parts.

I was thinking of starting a BOM (list of parts) and guide of suitable parts and where to get them.  Would this be useful?
If so is there already a site where this information could go?

Yes, please put together the BOM for v1.1 Minimig and ask Dennis if you can post it on his official Minimig website.

[whiteb]

With the CURRENT minimig 1.1 boards.  you *HAVE* to use the EXACT chip.  You might be able to find a pin compatible, but the core would be different.  Either way, a Board Re-trace would be needed.

[koaftder]

amigadave wrote:

nBit7 wrote:
A number of the parts on the minimig can be substituted with functionally and physically equivalent (or in some cases better) parts.

It appears that there are a number of people trying to put Minimigs together but lack the expertise to find and choose suitable alternative parts.

I was thinking of starting a BOM (list of parts) and guide of suitable parts and where to get them.  Would this be useful?
If so is there already a site where this information could go?

Yes, please put together the BOM for v1.1 Minimig and ask Dennis if you can post it on his official Minimig website.

The BOM he listed is just fine. To put together a full BOM with every resistor, cap and diode is kind of a waste. Part availability comes and goes, a complete BOM today is almost useless tomorrow. This is the nature of low production runs.

[nBit7]

With the CURRENT minimig 1.1 boards. you *HAVE* to use the EXACT chip. You might be able to find a pin compatible, but the core would be different. Either way, a Board Re-trace would be needed.

The only only one source (manufacturer) IC parts on the board are the FPGA and PIC.  Even there there are number of exact part numbers that are functionally and physically the same.  Only differing by temp range and speed grade.

Things like the RAM, Diodes, RS232 driver and voltage regulators can be replaced with parts with (in some cases) completely different part numbers.

[nBit7]

The BOM he listed is just fine. To put together a full BOM with every resistor, cap and diode is kind of a waste. Part availability comes and goes, a complete BOM today is almost useless tomorrow. This is the nature of low production runs.

Yes listing *every* alternative would be a waste of time.
I was only thinking a limited range of alternatives.  Perhaps 3 to 5.  0805 Rs and Cs only really need to give one example as it dosn't take much skill to choose them.  On the other hand you have to know a reasonable amount about electronics to pick a alternate diode.