How to build encoder using cxa1645?

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Rade K

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Are there instructions anywhere that detail the best method of putting together your own encoder using a sony cxa1645?

If not, can anyone help me out with what parts I need besides the chip and some resistors and capacitors?
 
Xian Xi

Xian Xi

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schem2wj.jpg


http://www.assemblergames.com/forums/showthread.php?t=6467
 
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Rade K

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Wonderful, thankyou.

I'm going to rip up an old PSX>
 
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Rade K

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The Webmiester said:
that'll work for jamma games?
Click to expand...


As long as it spits out a RGB signal (which is part of the JAMMA standard).
 
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The Webmiester

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thats pretty amazing, I wonder why I've never heard of using a 1645 before? My value village has scph-1001's by the barrelfull. Maybe I'll pick one up and start on a supergun or CMVS.

What else would have 1645's in them? What do old Sony VCRs use and whatnot?
 
SpamYouToDeath

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I believe VHS tapes just store a composite signal (?).
 
SpamYouToDeath

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Is there any place to buy these in bulk? Or are old PSXs the only place (I've got extras but don't really want to scrap them)?
 
Lochlan

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Good luck building an encoder with a surface mount IC!

I've been looking for the DIP package for awhile, unsuccessfully.

Or are old PSXs the only place (I've got extras but don't really want to scrap them)?
Click to expand...

Only model 1001 with the RCA jacks on it. I believe certain early Genesis models have it also, but IIRC it's a crapshoot to find one in a Genesis.
 
Xian Xi

Xian Xi

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Lochlan said:
Good luck building an encoder with a surface mount IC!

I've been looking for the DIP package for awhile, unsuccessfully.



Only model 1001 with the RCA jacks on it. I believe certain early Genesis models have it also, but IIRC it's a crapshoot to find one in a Genesis.
Click to expand...

The 1645 comes as both a DIP(1645P) and an SOP(1645M) surface mount chip.

Is the one in the PSX surface or DIP?

You can actually buy a 1645M off ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140125991696
 
Lochlan

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Xian Xi said:
The 1645 comes as both a DIP(1645P) and an SOP(1645M) surface mount chip.

Is the one in the PSX surface or DIP?

You can actually buy a 1645M off ebay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140125991696
Click to expand...

I have never checked personally but after reading some threads at ASSembler and shmups (IIRC) I'm almost positive it's surface-mount.

Awesome link! $30 shipped seems a bit pricey, though.

Edit: actually I don't think it was shmups. It was at pcenginefx, which has an AWESOME thread about building the circuit.
 
Last edited:
segasonicfan

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Don't forget the TTL oscillator needed for pin 6 input. Unless you only like black and white video games ;)
 
Xian Xi

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segasonicfan said:
Don't forget the TTL oscillator needed for pin 6 input. Unless you only like black and white video games ;)
Click to expand...

Here you go, pin 4 to pin 6 on the cxa1645

scin9xb.jpg


The chip is a 74HCT04

Parts list

Capacitors
10pF Ceramic
33pf Ceramic x2
10nF Ceramic
100nF Ceramic

Resistors
4.7M

Oscillators
3.579545Mhz Crystal
 
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Rade K

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I just purchased a neobitz-s from Jeff. For 30 bux, it's a great deal. All I want to do is get some svid out of my 32x in the most economical way.

Maybe I'll try to build my own encoder one day...

Also, Chris, are you saying you sold those sony chips for 400 each?


edit: 100 for 450 total.

$4.50 each...seems fair enough.
 
ttooddddyy

ttooddddyy

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Alternatively you could order a couple of AD equivalents (AD 724/725) for free evaluation purposes.
 
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