F4/FMPAC Light Combo Board project

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Van Alexey

Guardian (3204)

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22-07-2015, 19:07

madscient wrote:

Really interesting. I want to buy at least 20 pcs if you can sell!

We have some technical difficulties now. The board works, but something is not right, so we are investigating. When the problems are solved, I will let you know. There will be a new (fixed) board anyway.

Van madscient

Master (182)

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22-07-2015, 20:39

Alexey wrote:

We have some technical difficulties now. The board works, but something is not right, so we are investigating. When the problems are solved, I will let you know. There will be a new (fixed) board anyway.

I have found a problem in the schematics.
/WE of YM2413 should be dropped into ground, use /CS for write control instead.

FYI:
http://madscient.hatenablog.jp/entry/2013/06/06/120140

Van Alexey

Guardian (3204)

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22-07-2015, 21:26

madscient wrote:

I have found a problem in the schematics. /WE of YM2413 should be dropped into ground, use /CS for write control instead.

All FMPAC schematics have WR connected to WE of 2413. Our board works fine, but there are some other, probably power-related troubles. We are investigating.

Van madscient

Master (182)

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22-07-2015, 21:58

Alexey wrote:

All FMPAC schematics have WR connected to WE of 2413. Our board works fine, but there are some other, probably power-related troubles. We are investigating.

Oh, it's good.
I was talking about FMPAC schematics I saw:
http://www.geocities.jp/atx197/FMPAC_02a.pdf

Van NYYRIKKI

Enlighted (5875)

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23-07-2015, 21:21

If you can get it working and you make ready assembled board, I have only one thing to say...

Shut up, and take my money!

Van Alexey

Guardian (3204)

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23-07-2015, 21:46

NYYRIKKI wrote:

If you can get it working and you make ready assembled board, I have only one thing to say...
Shut up, and take my money!

We have the board ready. There's a minor design fault there that can be easily fixed or simply ignored. The board works, both amplifier parts work as they should, the sound is great... But something is not right with the MSX where it is installed - it freezes. We suspect a power related problem. We are now investigating whether this is a bad soldering issue or a nastier design fault...

Van DJs3000

Expert (104)

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01-08-2015, 16:04

Van Grauw

Ascended (10064)

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01-08-2015, 17:49

Nice! Why did it restart with less RAM?

p.s. I see the YIS503IIIR doesn’t have that little front slot that my CX5MII has Smile.

Van Alexey

Guardian (3204)

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09-08-2015, 09:21

We are going to put an optional ROM chip on board as old games don't seem to detect FMPAC without BIOS. Also Dmitry will try to add FMPAC BIOS to the additional ROM image on the modified Yamaha MSX2+. There's 16kb free space there.

Van Alexey

Guardian (3204)

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10-08-2015, 03:03

The board layout with the optional FMPAC ROM is ready. On the schematics that we have the ROM is connected to CS1 and SLTSEL pins of a slot. So my question to Jipe and other hardware gurus is: can this board conflict with any cartridges inserted into MSX slots?

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