Need info from V9990 owner

By FarmerPotato

Supporter (5)

FarmerPotato's picture

28-01-2020, 16:58

I'm developing V9958 and V9990 video cards for my homebrew computer.

One thing I'm not sure about from the V9990 data manual is the chip package! No drawing in the data manual!

I think it's a TQFP-128 with 0.8mm pin spacing. That makes the package 28x28mm.
Then I'm not sure how long the pins extend (there are 3 known lengths for TQFP-128.)

So I would appreciate if someone with a Tecnobytes or other card could measure
the V9990 chip body and the pins to a 1mm tolerance. Like, confirm the body is 28mm, and the pins add 1mm or 2mm,
to make it 30mm or 32mm across.

A collector is loaning me one new V9990, on the condition that I test it and return it (unsoldered).

So I need to order a chip test socket (clamshell type with gold-plated grooves for pins). These are pricey ($140).

The future plan is to order 50 chips (min qty) and test each one.

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By lintweaker

Champion (312)

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28-01-2020, 18:32

I can not help you with measuring right now. If you need/can spare a few of the V9990's I am happy to take a few!

By Jipe

Paragon (1404)

Jipe's picture

28-01-2020, 18:43

By Robby

Master (194)

Robby's picture

28-01-2020, 19:40

Where do you live?

By Grauw

Ascended (9382)

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28-01-2020, 19:41

Here is the V9990 datasheet which includes package measurements:

http://map.grauw.nl/resources/video/yamaha_v9990_datasheet.pdf

(I just added it.)

By lintweaker

Champion (312)

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28-01-2020, 19:51

Robby wrote:

Where do you live?

In NL.

By FarmerPotato

Supporter (5)

FarmerPotato's picture

29-01-2020, 00:45

Thank you Grauw. That is what I needed. I only saw the Application Manual before.

I am still interested if anyone wants to sell me one V9990 chip. My offer of a loan depends on the collector finding his chips (and he has collected a lot of chips.)

lintweaker, I would be happy to share out from a batch of 50 (I can't imagine making 50 computers.) I can't order the 50 chips until I have a proven test board. You can understand the risk of getting bad chips, or counterfeits.

I'm still designing the analog part of the V9958 board. Fortunately, the analog part will be shared with the V9990 board. So when the V9958 board works, I can make a V9990 board with high confidence that it's ready to try out a chip.

By lintweaker

Champion (312)

lintweaker's picture

29-01-2020, 17:31

FarmerPotato,

Maybe the Kiwi 68k computer is of interest, it uses a V9990 for video:
Kiwi 68k homebrew

I have plenty of projects going on, drop me a line when you're ready.

By Robby

Master (194)

Robby's picture

09-02-2020, 17:52

lintweaker wrote:
Robby wrote:

Where do you live?

In NL.

I mean farmerpotato.

By erpirao

Paragon (1101)

erpirao's picture

09-02-2020, 22:05

What specifications would your project have?
semi-compatible MSX?