Neo Geo CD Official CD Upgrade Thread

Joined Aug 2006
1K Posts | 0+
Gualeguay, Entre Rios, Argentina
This thread is for the advancement of the Neo Geo CD Hardware. mods such as: drive speed upgrade, region switching, component video upgrades, controller adaptors, processor upgrading, etc. Lets push the Neo Geo to the max!

First on my list is to get rid of that annoying loading ;-)

To get the process started, here are some close up shots of the Neo Geo CD Interface board. Let the research begin ;-)

235431356_cb66a8d903_b.jpg


235431361_15b0c90b1c_b.jpg
 
nice :) when everything is finished... we can get it into a tech doc format and load it up on the site and get the images there as well :)

Thank you for your help! AND thank you for this fresh Neogeocd.net content :)

BV :hat
 
Data on the chips in the above pictures.
http://www.megaupload.com/?d=LAN5NLL4

Interesting pictorial of a pc cdrom drive.
http://www.pcdoctor-guide.com/wordpress/?p=1396

Some stuff from wikipedia:
By increasing the speed at which the disc is spun, data can be transferred at greater rates. For example, a CD-ROM drive that can read at 8x speed spins the disc at up to 4000 rpm (compared to the 500 rpm maximum for 1x speed), giving a transfer rate of 1.2 megabytes per second.

Data Transfer Speeds
X Mbytes/s Mbits/s Mebibits/s
1x 0.15  1.2 1.1444
2x 0.3   2.4 2.2888
4x 0.6   4.8 4.5776
8x 1.2   9.6 9.1553
10x 1.5 12.0 11.4441
12x 1.8 14.4 13.7329
20x 3.0 24.0 22.8882
32x 4.8 38.4 36.6211
36x 5.4 43.2 41.1987
40x 6.0 48.0 45.7764
48x 7.2 57.6 54.9316
50x 7.5 60.0 57.2205
52x 7.8 62.4 59.5093

Obviously even a 4x or 8x drive would make the games load quite a bit faster. I need to get my hands on a older, non-dvd pc cdrom drive.
 
I hope it works...  I am very interested to see if it does.

For some reason, I recall a few people talking about this and theorized that it wouldn't make a difference.  The reader may read at that speed... but it depends on what the limits are on the memory (or after the data is read ... wherever it goes).  Does that make sense?  :-\

REGARDLESS... why not test it out, eh? :)

†B†V† :hat
 
This is true, It can only do so much. There is still the 8meg memory limit. Metal Slug 2 will always load levels in pieces, etc. What it would improve is the actual load time. For instance, if a game takes 40 seconds to load initially, it should take only 5-10 with a 8x cdrom. There is no guarantee this will work, but I would like to think it will ;-) And now for more info:

There are 6 wires connecting to the motors:
Brown +Red = The "brake pedal" which senses the laser hitting the CD center
Orange + Yellow = Laser Motor
Blue  + Green = Spindle Motor

2 Sets of connectors for the laser pickup. One is 5 pin, the other is 6 pin. The laser is made by Sharp and is model HB147AF.


http://www.vcdpickup.com/SHARP.htm << just found this. These lasers have the same wiring connection (5 + 6 pin connectors)
 
wouldn't that depend on transfer times to the ram... buffer speeds..etc?

just curious... I don't know everything tech... but I picked up on some stuff :)

†B†V† :hat
 
The way faster speeds are achieved is by increasing the rate the CD spins at. Special measures must be taken to achieve speeds beyond a certain point. IE. there is a 72x CD drive which utilizes lots of lasers to read more at once.
 
rossdh said:
The way faster speeds are achieved is by increasing the rate the CD spins at. Special measures must be taken to achieve speeds beyond a certain point. IE. there is a 72x CD drive which utilizes lots of lasers to read more at once.
Oh yeah? they finally broke the 58x barrier then?

For a long time, they've had troubles with the CDs shattering in the drive from being spun too fast. So maybe the additional lasers allow it to spin at a fast rate... but not to exceed the rate at which they shatter.

:lol Some of the faster CD roms drive trays opened too fast, and the CD wasn't done spinning... essentially launching the CD. they didn't go far, but someone I was talking to said it happened to them... I can't remember who...

†B†V† :hat
 
BTW, PC drives operate off 12V and 5V leads. Neo Geo CD has 5V and 10V leads. I'm not sure what the PC drive motor REALLY operates on, it may step the voltage down internally. Maybe stick a voltmeter in there to measure it.

I think the 4X drive will be my choice for this project when I do decide to go through with it. Anything above that is excessive, and like you said may be too much for the bus. Ill have to research the throughput of the Sony microchip's bus first too.
 
retro junkie said:
Evidently there must have been no progress in this experiment. Failed?

I haven't heard.

But I still question whether it will work. There is still a debate that the CD's were burned at 1x... so technically they can't be read faster than that (theoretically) without problems.

Whether that actually happens, I'm not sure. I can't find a good document anywhere to explain this. I've heard others say that if it's burnt at 1x, you can't read much above that.


Bv :hat