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r0jaws
3rd January 2010, 22:49
This as turned into a bit of a head scratcher for me.
I was lucky enough to have been given an Mp3@64 for Christmas and I have been looking forward for an opportunity to install this and to that end, decided to put a bit of time aside today.
Unfortunately, the device itself doesn't clearly mark where pin 1 is, one corner does appear to have a silvered circular mark that 'could' indicate pin 1, or it could just be a blob of solder. :huh:
I know that the clockport on the 1200 chucks 5v down one line so I'm quite keen to avoid any "Magic Smoke" incidents, and the warnings I have read about correct orientation have ranged from dire to catastrophic.

Therefore I have spent much of today and this evening fruitlessly searching for an inkling to the correct installation orientation.

I am also planning on using a cable to connect the expansion so that I can hopefully fit it adjacent to the existing audio outputs. Is there likely to be much degradation in signal caused by a cable that is 20cm long?

Any help would be most gratefully received.

rkauer
4th January 2010, 03:30
A way to tell is looking on the back of the board, where two pads are ground. Just check it with the clock port pinout.

Back of MP3@64:
http://bboah.amiga-resistance.info/download_photos/mp3at64_back.jpg

Zetr0
4th January 2010, 08:29
@r0jaws

my friend I think this is what you are looking for -

I put this together by using the data from Stedy's site (http://www.ianstedman.co.uk/Amiga/amiga_h_w/clock_port/clock_port.html) and images from here and amiga.resource.cx

How to (which way do I) connect an MP3@64 to my A1200 Clockport -

The clock port layout on a 2B A1200 -

http://www.guildserver.co.uk/data_images/schematics/mp3a64-ori/rev2b.PNG

The clock port layout on a 1D A1200 -

http://www.guildserver.co.uk/data_images/schematics/mp3a64-ori/rev1d.PNG

here is the overlay of the MP3@64 -

http://www.guildserver.co.uk/data_images/schematics/mp3a64-ori/mp3@64-orientation.PNG

hope that lots helps. as with all things double check, but I am pretty sure this is the orientation of the MP3@64 device on the A1200 motherboard.

r0jaws
4th January 2010, 10:50
That looks great, thanks a lot guys. I'll have a check and try later on and post back with results. :D

r0jaws
4th January 2010, 22:11
Ok, update time.
I stripped out every expansion from my 1200 before testing this, as TBH, my heart isn't good with heart-rending loss caused by bumbling incompetence. ;)
So no Blizzard, Bvision, Indivision SD/FF, Hard Drive or CD-ROM, just a bare board and the Mp3@64.

I didn't even hook up the monitor or sound cables, just the basics so that I could hear it boot to the floppy click to know it was working before going any further. Plus I limit my damage to just the mobo and Mp3@64.

I attached it to the clockport by way of a cable from my Subway USB and some pins half inched from an IDE gender changer slotted into the female connector.

I spent about 10 minutes checking the orientation to ensure that the 2 ground on the expansion and the 2 ground on the clockport were in the same place and finally plugged it in as shown below.

http://i94.photobucket.com/albums/l119/r0jaws/a1200%20Upgrades/Mp3644.jpg

I fired her up and waited for the inevitible plume of smoke. None came, however after about 20 seconds I noticed a distinct smell as of hot components and switched everything off. I felt the cable and it was cool to the touch, but the Mp3@64 was absolutely scorchio!

It was quite a bit hotter than I would expect, and I believe that I must have fcuked up somewhere along the way.

Following big Z's link to Ian Stedman's site I had a good read of the clockport configuration and noticed a little something that has me confused.


The usable pins are located on conector P9B. P9A and P9B are next to each other on the motherboard. P9A pin 1 is marked on the PCB. If you then count along in sequence (1,3,5 top row, 2,4,6 bottom row) you will come to the first clockport pin. All numbers below are in relation to pin 1 of P9A.

It seems a little unclear to me which way up we are meant to count. The motherboard has pin 1 clearly labelled as the bottom left pin, but the sentence above suggests that the top left pin should be 1.

This would completely reverse the whole layout and would mean that I could have hooked up 5v directly to my Mp3's ground. :Doh:

Is this likely to be the case? I know I'm being cautious here, but I've learned my lesson the hard way in the past, and I have invested to much in my 1200 to watch it immolate itself.

rkauer
4th January 2010, 23:05
Using pins strips to connect a female plug in another female plug will invert the rows, so bottom is top and vice versa.

Sack the cable out and then hook the board directly on A1200's clockport.

r0jaws
5th January 2010, 00:00
That'll be it then. Thanks rkauer. :Doh::Doh:

However, the ROMs obstruct fitting the Mp3@64 in it's correct orientation. There are risers available from Amigakit, but that would mean I would not be able to fit this inside the console case.
I guess I will have to find or fabricate an appropriate cable instead.

rkauer
5th January 2010, 18:07
Ask Amigakit for one. Or make one yourself. Our great friend Zetr0 is one who can check the cable for you when it's done.

Zetr0
6th January 2010, 01:49
oh dear....

fear not, I think we can save it, or atleast bloody try my friend, emergencey triage will be awaiting on Friday =D

damned Interleaved cables!