Replacement of PC9821 CD-Rom - Guide (Work in Progress)

[SkyeWelse]

Hi everyone,

in another thread I had mentioned that my PC9821-Ce2 computer did not come with a working CD-Rom drive. Fortunately, Kobushi recommended me a compatible CD-Rom drive that will work with the NECCDM.SYS driver when loaded in PC-98 Dos:

http://www.retro-type.com/PC98/files/CD-ROM-boot-disk-Newer-CD-Roms.zip

The recommended drive that has been tested working between Kobushi and I is the Mitsumi cr-4804te drive and I can also confirm that a standard DVD-Rom drive from Dell, which was a Toshiba TS-H352 will also work with this driver. *Note* While it may seem as though the PC9821 has frozen during startup when the CD-Rom is connected to the IDE ribbon cable, it should eventually load either your Harddrive or FDD disk after a few minutes. It seems that with these later-in-life drives, it take a bit longer for the PC98 to start.

I decided to do this guide for the Mitsumi drive because A) this might be a popular drive to use for those who need to look for a replacement B) It's the same color (beige/white) as the Ce2 case C) there were no modifications needed to the actual drive tray. In my Toshiba drive, I actually had to trim the plastic edges of the drive tray in order to get it to eject and not get stuck on the Ce2 case and it was black in color and did not really match the look of the system and it stood out in a bad way.

Part 1: Dismantling the CD-Rom Drive/ Faceplate / Eject Button (Optional)



-Remove the top seven screws and keep in mind that the front left and right screws are small screws, the rest of the screws removed are longer.



-Removal of the Top Cover




-Removal of Faceplate. I used a long screw driver on each side of the front face plate's tabs, 2 on each side and pried them gently back and away from the black clip they were hooked onto.





-Removal of spring assembly from drive tray door and removal of drive tray door.

(*Optional, only need to remove these if you plan on removing the big blue eject button for your mod)
--------------------------------------------------------------------------------------------------------------



-Removal of the bottom seven screws.



Slide CD-Rom Interior back and out from the bottom metal case.




-Removal of blue Eject button by pulling away from CD-Rom assembly (towards yourself)




-Button has been removed.
---------------------------------------END OPTIONAL -------------------------------------------------------

In my case, I decided to keep the blue Eject button simply because it offered more of a hit area for the Ce2 case button to make contact with.



-Drive installed with blue Eject button retained.

Part 2: Modifying the PC9821 Faceplate (Ce2 Case)



-Ce2 faceplate showing the drive tray opening and eject button.



-Overall idea of the mod. The idea is to get the Ce2 / PC9821 faceplate button to make contact with the Eject Button. On the original drive that this came with, which was an NEC CDR-260(PI) the eject button was about an inch to the left of where this Mitsumi drive's Eject button is located. So the normal button which presses a piece of plastic (where the red + is indicated in the photo above) was originally where it would have normally made contact with the NEC CDR-260 Eject button.

A few of problem areas here that must be decided on for this mod to work correctly:

1. The Mitsumi Drive (at least mine) has a fairly sturdy steel plate that will make contact with the red + plastic piece that was intended to make contact with the orignal CDR-260 drive. Because this steel plate is there, it make it a bit more difficult to get the button to work as intended on the Ce2 / PC9821 faceplate. Now, you can most certainly "cut" this piece off if you believe there is no chance of you ever getting an original working CDR-260 drive working for your machine. But by doing that you are making the decision to destroy part of your original case, and I decided not to go that route as I wanted to keep this all as intact and original as possible.

2. Because this red + plastic piece is aligned with the steel plate it can actually push against the CD-Rom drive and make the overall faceplate feel as though it's not completely flush with the rest of the computer when clipped on. You'll likely see evidence of this around the FDD drives not seating perfectly. Again, to solve this issue you could cut that red + plastic piece out if you like or, you can follow some steps below in the guide for how I circumvented this without destroying or removing the plastic faceplate pieces.

The best way to get started is to find a small piece of plastic that you can use to wedge into the hollow slot that the Ce2 faceplate has on the inside of the case.



-I decided to use a plastic clip that I broke off of the another CD-Rom drive's faceplate  that I had tried earlier, but any slim plastic piece could probably do the trick.





- Pushing the plastic piece into the slot as described above. I had to test this a few times by putting the faceplate on and cutting the plastic piece little by little and/or bending it upward just slightly to get the right amount of space to hit the blue Eject button without constantly pushing against it (making the drive open/close/open/close, to infinity and beyond).

In my case, it helped a bit to loosen the tension screw holding the plastic piece down (marked ABS) in the photos above. Doing so allows for the side nearest the screw to now push and move forward acting as a new button, instead of the opposite side only (which if the red + plastic piece was not removed, is now likely flushed against the side of the Mitsumi drive steel plate) which is not going anywhere when you push this button.

It takes a few tries to get it just right, so you may need to remove the plastic piece and trim it. *IMPORTANT* make sure you are holding down the plastic ABS piece when pulling your little plastic piece out or you can risk snapping the ABS piece off entirely!

TIPS to make this process a BIT easier.
----------------------------------------------------




- Originally I had a screw on the side keeping the drive locked into place with the rest of the metal frame housing the CD-Rom and harddrive (if there was one in there, there is not in these photos.) This can be nice to have if the CD-Rom is loose, but in my case, this was surely not the issue. My issue was that everything was far too tightly pressed against the + plastic piece and the plastic piece I installed against the blue Eject button. I really needed only a few millimeters of space for this to be seated perfectly, which meant that my screw holes would no longer line up correctly to place a screw in, so I removed this screw.

And...




-Used good ol' fashioned electrical tape on either side of where the cd-rom hits the metal housing frame. It's not pretty to look at, but so far I think the only way to get around this with this particular drive would be to "cut out" that original plastic + on the ABS plastic piece. My CD-Rom doesn't move though and it doesn't push back out of the range of the Eject button either when I taped it, so it works for me, but surely there could be better methods of making this look more professional perhaps.



-Everything is aligned as I snap the Ce2 faceplate back on.




-Open and Closing of CD-Tray using Button on Ce2 Faceplate. Success!

Part 3: Placement of original PC-9821 CD-Rom Tray cover / LED Lights (Still a work in progress)

So the original CD-Rom that came with the Ce2 has a small plastic piece that would normally hook on to the CD-Rom drive tray and would be flush with the hole in the Ce2 faceplate when the drive tray is closed. Unfortunately, at least in the case of using the Mitsumi Cd-Rom or the Toshiba DVD-Rom drive, this little piece will not clip on without having some of it's plastic cut away or altered. Also, this plastic piece is made an a bit of an angle, where one side of it is designed to jut out a bit more on one side than the other since the Ce2 faceplate is curved a bit. i'm not yet willing  to make modifications to the original piece as shown in the photos below, and there is not enough room for it to fit "on top" of the Mitsumi CD-Rom tray when it closes since the tray comes in just below the top of the hole for the tray allowing it to barely fit without hitting any edges of the hole.




So for now, I'll be putting this project on hold until I can find another plastic cd-rom tray part that I think will work for this and still look pretty decent with the Ce2 faceplate/case.

Another part of this project still remaining is detaching the LED lights from the original PCB of the Mitsumi CD-Rom drive and extending it out via wires run to the LED light square location on the Ce2 since the light from the LEDs on the Mitsumi CD-Rom are not close to the LED light square on the Ce2 faceplate.

Hope this helps those who have purchased their new PC-9821 computers who are in need of a CD-Rom replacement.

-Thomas

[RobIvy64]

Nice work! I'll be following this, as the drive in my Cs2 does not work.

[kobushi]

Nice work! Looks better than my Frankenstein setup.

[SkyeWelse]

Thanks! Hope it ends up being useful to some of you all.

One last thing I wanted to mention was that even though I've not yet been able to attach the original cd-rom tray/faceplate or one like it to the tray, the little faceplate will still fit inside the slot just fine when the CD-Rom is not in use. Just make sure you *remove* it before you decide to eject your CD tray or it will definitely get stuck. I figure, there may not be too many times where we'll really need to be using our CD-Roms, so in most cases we'll probably only connect them and use them when we absolutely need to such as installing something from a CD-Rom version to be put onto the harddrive, so we could probably get away with this just fine when the drive is not in use and just remove the plate once we need to use it. Pushing on either left / right side will easily pop out the plate for easy removal.



It keeps it looking like the original at least.

Now to work on getting that second replacement FDD to put in the very obviously missing Slot B...   

-Thomas

[eidis]

 Hi SkyeWelse !

Could you please post pictures of the original drives laser pick-up or try to identify it in the following article ?

Laser pick-up assemblies
http://gamesx.com/wiki/doku.php?id=laser_pick-up_assemblies

Keep the scene alive !
Eidis

[SkyeWelse]

Hi Eidis,

Wow that is quite a comprehensive list of Laser Assembly parts!

The original CD-Rom drive used in the PC9821-Ce2 is a NEC CDR-260(PI).

The underside of both the laser assembly and the motors have identifiers.

The laser assembly has a white sticker that reads:‏
SPU3034 < line 1‏
39E42AA < line 2‏

Picture

From the list above, I do not see the exact Laser Assembly pictured, but it looks it would be a new one called a NEC SPU3034.
 
The first motor has something written on the side‏ which was a bit difficult to read:
MDN3GT3DYAS‏
05FEB94S1‏

Picture

The second motor shows:‏
PPN-13MK051 (+) Probably indicator for where to connect the positive wire‏
[M]‏ 26194KC-U‏

Picture

I did find a drive on eBay the NEC CDR-260R, which is another Real-Mode Driver Required CD-Rom Drive. However it did not work when I first received it as though it received no power when power was supplied to it.

Here is a comparison shot between the original 260(PI) and new 260R.

It's not a very good photo since it was taken at night, but they do have similar parts being used. I'd have to look again and update this thread later with the part numbers of the 260R drive. The main difference that I can see is that the main ribbon cable is a bit different. There are 3 more trace lines on the 260R that lead to the top-left of the drive that sites just north of the left-hand motor. In the original 260(PI) drive, instead of those extra lines on the ribbon cable, there are instead 3 wires from that area , two purples and white that connect to a 3-pin connector that connects to a spot on the PCB itself. That's really the main difference between the drives internally.

The CDR-260(Pi) is only a CD-Rom with no additional features and one LED light, whereas the CDR-260R has a volume control switch, headphone jack and two LED lights.

My plan is to possibly take both drives apart one day and see if I can see which parts might work. The Laser Assembly at least clips on via a connector to the main ribbon cable in both drives and at first glance appears to be the same Laser Assembly.

-Thomas

[eidis]

 Hi Thomas !

According to the following site the optical pick-up is indeed a NEC SPU3034

http://www.vcdpickup.com/bakup%20index.htm

The drives look very identical and I suspect that most of their main components could be interchangeable just like in the case of X68000 slim 5.25" and Canon MD-5501 5.25" floppy drives. Do both laser pick-ups have the same number of pins ? If yes, then try to examine where they go to the motherboard and it could be that all that you need to do is transplant the laser pick-up from 260R to 260(Pi) to resurrect the original drive.

Keep the scene alive !
Eidis

[SkyeWelse]

Thanks very much Eidis, I will try doing just that someday soon.

-Thomas

[papa_november]

My CD drive died too, and I used a Panasonic drive from the late Beige Mac era (think early G3 when they went to IDE drives) as a replacement. I had to take the entire front off the drive, and add a bit of plastic to the eject button actuator on the front of the PC-98 case. I also was able to get the drive door mounted correctly, though I had to mangle the tray a bit.

The biggest headache is finding a drive that has the eject button and access light in at least sort of the right place, as well as a tray that is positioned at the same height as the dead OEM drive.

[SkyeWelse]

Hey Papa_November, I remember you from Tokugawa. Nice to see that you are here as well! And... from your post count, seems like you've been here for quite some time! 

-Thomas

[dasfool]

Sorry to drag up an old thread but it seems pertinent to my question so I'll give it a try.

I know this original thread was specific to replacing the CD-Rom drive in a PC-9821 Ce2, but could this same drive (Mitsumi cr-4804te) be used to easily add a CD drive to something like a PC-9821 AP2 (a-mate series)?

[YetAnotherJPCUser]

I'd like to replace the CDROM drive of my PC9821Ce2 as well. I've downloaded the fdd image CD-ROM-boot-disk-Newer-CD-Roms.zip

Unfortunately none of my CD drives are recognized. I've tried 4 different models from Mitsumi, LG, Goldstar and Plextor. I always get the following error when booting from floppy:

Device driver not found: 'CD_101'.
No valid CDROM device drivers selected

this error even occurs when I use the original NEC CDR-260! The laser is dead, but the drive should be still recognized.

I've jumpered the drives as Slave, because otherwise my PC98 does not boot at all. Furthermore I've tried it with the 2nd floppy disconnected and I've also tried it with the hdd disconnected.

I assume something is wrong with the boot disk.

I would be happy about a hint. Thank you.

[YetAnotherJPCUser]

I've got a TS-H352. Unfortunately it's still not recognized. I've also changed the cables and the jumpers, but the computer does not boot at all if I'm not using the original cable and Slave jumper.

Does anyone know if a specific BIOS version or setting is required to get this working?

[soviet]

In case someone is looking for a working drive the generic driver posted before works fine on this drive that I take from a computer found on the curve:


Works great now the delay when you power on the computer is quite long there's any way to prevent this ?