Author Topic: Inquiry about the TurboGrafx CD drive for the purposes of ODE  (Read 60 times)

BasementEngineering

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Inquiry about the TurboGrafx CD drive for the purposes of ODE
« on: February 01, 2024, 12:08:04 PM »
Good morning folks,

I have a project I have been working on for a few years, and was hoping that this forum would be a good place for information. I apologize to the moderators if I am in the wrong section or being a nuisance.

I have for a number of years, been trying to restomod a cd player from my old car. I have been searching for datasheets and information all over and trying to piece together what I can from what people have scanned in from 35 year old documents. I came across the Console5 tech wiki about the TurboGrafx CD drive and it lists the same chipset that I have in my CD player, with the same RF Amp CXA1081M, DSP CXD1135Q and ram, and the CXA1082BQ Servo Controller. The DAC that comes off of the DSP is also manufactured by NEC for what it's worth. All these elements are controlled for my CD player by a Pioneer co-processor unit that I can't find any info on other than what is in the service manual. I am wondering if you guys could help me understand how these chips interface in your units as I've seen some talk about optical drive emulation for your machines but I haven't been able to nail anything down. The reason I am asking is that I would like to keep the CD player part working (at least electronically), because replacement lasers are no longer a feasible option anymore. If one comes across ebay, they are usually $150-200, and still 35 years old. The suspension wires are usually corroded to where, if they are still intact, they break upon focus calibration.

I'm looking to figure out how to replace the mechanism with an optical drive emulator so that the lack of available lasers is no longer an issue. I can contribute the schematics and datasheets I have for my CD unit. I have a couple configurations for this chipset, and the manuals I have also contain (although poor quality since they were xeroxed in the 80s), oscilloscope pictures of the signal waveforms at the various test points. Perhaps those would help you guys keep your units running longer.

Here is a link to my forum post on this project. https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-radio-repair-restoration-having-issues-1148850/

Apoligies for the long intro post. I like trying to keep my old technology working, be it my old video game systems, cars, whatever. I'm not looking to make money, just to figure out how to keep stuff working. Thank you for your patience reading this, I hope I can bring something to your community and learn something for mine.

Keith Courage

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Re: Inquiry about the TurboGrafx CD drive for the purposes of ODE
« Reply #1 on: February 01, 2024, 10:04:05 PM »
You can get replacement CD lenses out of old sony discmans. Yes they are old but they usually work well.

Also, I installed a Bluetooth adapter in my old 99 Toyota Sienna stereo. I just used one of those cheap USB blue tooth adapters. Found 5V inside the Tape player and wired up the bluetooth adapter to the Tape cassette audio input. So now the tape player turns on the blue tooth adapter. I used something like one of these https://www.ebay.com/itm/223479042338?hash=item3408639122:g:1CQAAOSwRwxcr6UF&amdata=enc%3AAQAIAAAA4PRVza9ekKqD%2Bh8Iafv%2F5eWCj9StY%2FrpWl%2BzKwvzXp%2B3R7vTqYh2%2BDo8LM%2B338%2BPybCFSU%2BOt5TydZG6pj4Q4C8KPC%2FkkznWsqeqT9jc%2BN5wnPIsKNtTfW%2FuFhc5FtDFTv7oupo9QmlBz5epJ4%2BSXPyeEBKU70RHMcnBxT1ZVpstq%2FAx06QBksXBMhtXbX%2FzEkpYUfYW3Edr3Y85TvIoN3yJylhnFTYXJefK%2BsEiMIIhGtny60KlEs0U%2FJP78B7bfkF87Eo8%2FjeBba8R0cKTz2w39Ea%2FJDbdYxNsteQTZmGz%7Ctkp%3ABk9SR4S1q_ysYw

BasementEngineering

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Re: Inquiry about the TurboGrafx CD drive for the purposes of ODE
« Reply #2 on: February 05, 2024, 09:52:06 AM »
I can do something like that. I have a module that solders in to the tape deck as well that I did some initial tests on. Wasn't very good quality. The best audio I could get out of it would probably be to use the DAC that's already there. The DAC takes I2S audio data straight from the CXD1135Q DSP, converts and filters it before it goes to the rest of the system. There are a couple Mute lines that go to the DAC/analog filter. I'm not sure when they are activated. I can run an ESP32 there to put out the I2S audio to the DAC and the system should put out audio to the speakers as a direct feed, but would get mixed in if I had a tape or the radio on. I woudn't be able to see anything on the display, or use any of the buttons on the radio while using this type of setup.

I'm wanting to have an integrated solution that can run a CD image. I can simulate the action of loading a CD with the ESP 32 to fool the CPU into thinking it's physically got a CD in the drive. Once I can get the thing to play a CD image, I can sniff out the signals between the CD player CPU and the main CPU in the radio. This would allow me to eliminate the CD CPU, the drive, the RF amp, the DSP, and pretty much everything but the DAC and whatever I use to replace the CD CPU.

The fact that your systems have the same initial chipset for the CD player means to me that the chips I have can handle more than just audio format CDs. In your drives, do the DSP, Servo Controller, and RF amp feed to a central chip in the the drive, or do they go straight to a chip in your main console?