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88/89 - capable of swapping tape with slave CD?


SeanR
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Sean,

Not sure if anyone has tried this yet, but it might be worth a try if you have the needed parts to hook the CD player up to the cassette harness. I am wondering about this myself, as the radio module in the 88/89 cars is very similar to ones used all the way to at least the 1996 model year. Since the radio module outputs "commands" on a special communication line to/from the cassette, it would be interesting to see if these same commands would work on an outboard Delco CD player.

The radio/cassette/cd components of the 86-96 era were designed to be modular and interoperable so that many combinations of components could be put together depending on model, option package, etc.

In looking at the Toronado cassette deck from the mid/late 80's (these cars used the same radio module) these had dedicated control buttons (play, stop, ff, rew, etc) that were not present on the 88/89 Reatta and Riviera tape decks. Yet, they would appear to be compatible with the same radio. So, I'd say it is worth a try.

If I had everything I needed to try it here, I likely would have already.

KDirk

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Guest Mc_Reatta

I wouldn't hold out much hope for being able to use a slave CD player with the CRT as the software won't interface with it. If the CD player module has all the operating controls it needs built into it, (play, eject, etc.) then it would be easy to hook up the audio to play thru the radio in an 80's model. If someone finally cracks the software program in the CRTC then it would be possible to reprogram the computer to interface with it, (not easy, but possible) but there is little hope that the deck could be recognized and controlled with the standard code and set up in the car. This is assuming that the CD player would even accept digital signals sent over a data line to allow control of it.

A 90's didn't have a CRTC so it didn't have an entertainment data line to relay operating status and commands back and forth between the modules. The head unit and the radio module and optional CD were hard wired together to allow the remote operation of the modules.

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The 90-93 slave CD player seems fairly self-contained as far as controls go. Has all the necessary controls on the front, which mean the radio (or CRTC) shouldn't need to know a lot about it. So it seems plausible that it could be made to work. It would be relatively easy to try.

Hardest part might be finding a CD player that actually works. I've bought several at the Pick N Pull, and so far have batted 100% failure rate. So when retrofitting my Reatta, I chose the one with the best cosmetics and sent it to M&R for repair.

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Can you trick the CRT/BCM into connecting up a 90/91 slave CD player? I was hoping the wiring would be very similar or at least be able to modify the pinouts to make this work. Anyone done this before?

It should work but you WILL most likely have to find a radio brain out of an other gm vehicle that came with the slave cd player. I would look for a truck, caddy, or a regal custom. Anything 95to or older will work bc they used the same e&c (entertainment and climate ) bus.

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Guest Mc_Reatta

If that is the case, then it would be a relatively easy matter to hook it up to the radio module either thru the tape deck connection or the aux connection to have it play thru the system just as has been done with the mp3 player interfaces that have been covered here before.

In a 80's there are no controls at all on the cassette player module. All functions are controlled via the CRT and CRTC.

Thanks for sharing the info on the CD deck wws944 :)

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MC-

Not to beat a dead horse, but I would reiterate that the mid 80's Toronado had an outboard tape deck that had dedicated controls. This model (not used in the Reatta or Rivi CRT models) was nearly identical to the one without the controls and appears to be bus-level compatible with the RIM (radio) module used in the 88/89. As per a recent thread elsewhere here, the RIM module used in the 88/89 with the CRT is also the basis of the 90/91 factory radio, just with a integrated cassette deck and control "front end" grafted on. They used the same E&C data bus from 86 to at least 93, and some models used this until at least 1996. GM/Delco made these components highly modular so many variations of sounds systems could be built from a relatively small number of unique components.

I am thinking it entirely plausible that if the slave CD is designed to respond to E&C bus commands for play, pause, stop, FF and REW, that it my actually be "plug and play" with the CRT setup. What we don't know (yet) is if the CD player is designed to operate remotely by E&C commands, and if it will send the proper feedback to the RIM module to show "tape in" - or in this case disc in. If so, and I realize this is a lot of supposition, then I see no reason it wouldn't work.

FWIW, I am working on the CRTC program. I have already mapped the entire character font (actually two fonts, one small and one large; the third and largest font is actually the smallest just with the pixel size doubled by a software routine) and most of the icons (battery, temp, oil, fan, defog symbol etc.) stored in the ROM, along with the respective screen displays. I am still hoping to do some customizing, but I have already reversed-engineered the easy things to figure out. Now I am in to the executable code which is a whole different matter. Since this program was developed in a custom language, and the object code generated on a custom compiler, I am flying blind so to speak. Also, 8088 (the CPU on which the CRTC is based) machine code is not my strong suit, so I am struggling with it all the more. Worse still, there is also an 8031 co-processor and several other unique/custom control chips involved in this setup, so it is not all that similar to a conventional PC architecture.

If I ever get far enough along, there are several patches/mods that I would like to do. An interface for an outboard multimedia/nav center will be one of the big items on the list, by using the tape mode controls on the touchscreen. I'm a long way from that point now, but some progress has been made.

Hopefully Sean will try this and prove or disprove the notion that the CD player can be used with an 88/89.

KDirk

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Kdirk I believe the '86 Riv also has control buttons on it's tape deck. Now that Gibson's have lumped all the front wheel drive e-class cars [think I am right with that designation] in the same area, I look at them all and get a little confused as to which has what. They even thru the two seater Chrysler [can't remember the name, but it has opera windows] in the same mix. But the Fieros are all lined up on the exact opposite end of the lot.

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Hey Dave,

Interesting on that tape deck. I didn't realize that the 86/87 Rivi's had that version, I guess the tape wasn't controlled through the CRT in those two years? I know the radio was, but maybe they weren't that far along yet that the tape controls were programmed into the CRT system.

Think there is any possibility of you snagging me one of those 86/87 tape decks with the on board control buttons? Doesn't matter if it works. I have a couple of junked 88/89 style decks, and would like a early version with the integral controls to do some micro-surgery on. All part of my quest to reverse engineer the CRT subsystem in these cars.

Oh, and as an aside to this whole matter, the 88/89 tape decks have the openings in the front face plate for the dedicated control buttons. They are covered up by the brushed aluminum applique that surrounds the cassette door opening. If you press on the applique along the left edge of the tape deck face plate, you will feel the rectangular openings in the metal frame underneath the sticker. This is further evidence the two versions were basically identical, and the later version just had the on-board controls omitted.

KDirk

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Wow glad this sparked some discussion. I was checking out Ebay last night looking at slave CD units and had found that MP3 thread about fooling the BCM into thinking the slave was present. (knew of the BCM thing after reading a Fiero thread where some guy had installed a complete BCM system into a Fiero from a Firebird). I figured if the CRT is sending an "eject" command its nothing more than a signal feed so that it would work on ejecting CD's too.

My only hesitation is buying a slave CD unit without knowing what the terminated end looks like. Could someone please snap a photo of a stock 88 vs 90 termination end to see if the plugs are the same? If you have part #'s I'd just check it out myself.

Delco (GM) Chevy/Pontiac Remote/Slave CD/Cass Cable | eBay

So you guys know of a CD slave unit that has dedicated buttons? I guess that would be the one to snatch up to make this work.

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Sean,

The stock CD player that was optional in the 90/91 Reattas had on-board buttons for play, pause, track fwd and back, and eject. Since the stock radio in 90/91 had an integrated tape deck, it had no built-in controls for the CD player. The CD unit just mounts in the console cubby-hole area, and has a special remote harness that routes power and audio signals to and from the head unit. I am not even positive if it has a data communications line that runs between the radio and the remote cd player.

GM did have other outboard CD players used in other models & years. I distinctly remember a 6 disc stack-type changer that had 6 buttons - 1 for each CD but the main controls (play, stop, fwd, rev) were on the head unit and not on the CD player face plate.

I have no idea what year or model it was used in, just saw it laying in a pile of old stuff at a dealership once a few years ago. I only remember it because I was asking the parts counter guy about it, and he didn't know anything. I have to wonder if that type of player would work since it must have relied on E&C bus data to send the control signals for play, stop, forward/reverse and so forth. I'm also thinking that model probably sent the timer data to the main radio display to show the elapsed track time on the radio display when a CD was playing.

Another issue here is that the factory CD player really wasn't that good compared to current offerings. Yes, it is a basic CD player (better than tapes) but it is not common to find one working anymore (plan of having it repaired if you do find one, or buying an already rebuilt one). Also, without modification to the optical pickup block it will not reliably play CD-R's or RW's, only factory pressed CD's will work in it. You may want to consider those shortcomings.

KDirk

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If I wasn't prepared to handle disappointment I wouldn't be owning 3 GM vehicles. LOL

I was reading this truck forum about the single vs. upgrading to 6 CD slave unit here. CD Player to 6 Disc Changer (GM/Delco Unit)

On Ebay, found a 6 slave unit. You are probably right in that it may not work but I'm willing to try. However, it should start playing the disc. Tough part is that may not be able to skip/scan through certain tracks without dedicated buttons.

GM CHEVY 6 CD CHANGER REMOTE AUX SLAVE GMC YUKON DENALI | eBay

Just would definitely like to see pics of the cabling pinouts between the stock Reatta tape and CD units.

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Hey Dave,

Interesting on that tape deck. I didn't realize that the 86/87 Rivi's had that version, I guess the tape wasn't controlled through the CRT in those two years? I know the radio was, but maybe they weren't that far along yet that the tape controls were programmed into the CRT system.

Think there is any possibility of you snagging me one of those 86/87 tape decks with the on board control buttons? Doesn't matter if it works. I have a couple of junked 88/89 style decks, and would like a early version with the integral controls to do some micro-surgery on. All part of my quest to reverse engineer the CRT subsystem in these cars.

Oh, and as an aside to this whole matter, the 88/89 tape decks have the openings in the front face plate for the dedicated control buttons. They are covered up by the brushed aluminum applique that surrounds the cassette door opening. If you press on the applique along the left edge of the tape deck face plate, you will feel the rectangular openings in the metal frame underneath the sticker. This is further evidence the two versions were basically identical, and the later version just had the on-board controls omitted.

KDirk

As I haven't sent your package yet and that this is probably my slowest week of the year, I will be happy to go back out to my favorite local U-Pick [in the future it will be called Gibson's] to get what you need. I will throw it in No Charge, and put it on the "you owe me" list. lol

PM me with anything else you need, I'll probably be heading out about 9 am Central time.

Same for you McReatta...

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I would not try using a slave player from the mid-90s onwards. Very different from the earlier ones.

There are two connectors between the head unit and the cd player. One is mostly audio and the other has power, lighting, etc. And yes, there is some sort of e&c bus connection. A scan tool can get to it. The schematic showing all of this is in the FSM.

Edited by wws944
fix typos. (see edit history)
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Folks: some years ago I posted in the docs section of Reatta.Net the 3E, 3F, and CD adapter sections from the Delco Radio service manuals. Do you have a problem reaching ?

Now I have never tried this myself but it seems simple enough. J508 is the connector on the tape that goes to the radio. (image below)

On the radio, J302 (16 pin) is the input and is appears that pin 9 - left audio, 10 r audio, 11 audio gnd which most have discovered however the magic pin is 13 (tape on) and from the schematic you apply power. What I do not know is what the "on" value is: 14v, 8v, or 5v.

post-31022-143138779854_thumb.jpg

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Folks: some years ago I posted in the docs section of Reatta.Net the 3E, 3F, and CD adapter sections from the Delco Radio service manuals. Do you have a problem reaching ?

Now I have never tried this myself but it seems simple enough. J508 is the connector on the tape that goes to the radio. (image below)

On the radio, J302 (16 pin) is the input and is appears that pin 9 - left audio, 10 r audio, 11 audio gnd which most have discovered however the magic pin is 13 (tape on) and from the schematic you apply power. What I do not know is what the "on" value is: 14v, 8v, or 5v.

Hi Padgett. Are these pinouts the same on the tape slave and the CD slave? I noticed their is a white plug (power?) and a black 9 pin on the tape units but just a black 9 pin on the CD slaves at least that's what seemed to be from Ebay pics I was looking at.

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Well there is a 14v (battery) connection that I imagine is live when the radio is on. Guess it depends on how much poer it needs.

My main interest was the "tape on" (pin 6) that I suspect is what switches the amplifier from radio to tape input.

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this sounded real good to me until i realized that cd players are old technology.i have all my cds on my phone.i just universal mount my phone,plug in my mp3 wire hooked to the old cassette wires and have my chose of 192 albums to listen to.it isn't cd quality but it sounds good to me.my cd player in my camaro works and i never use it.just my opinion.

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Guest blue72beetle

That's true, and that's what I do now, use my phone. However, my phone is touchscreen, and it takes a bit of concentration to make sure I'm not hitting the wrong thing. Plus, now that texting and driving is outlawed here in Indiana, I'd hate for a cop to mistake me for texting when all I was doing was hitting the next song.

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That's true, and that's what I do now, use my phone. However, my phone is touchscreen, and it takes a bit of concentration to make sure I'm not hitting the wrong thing. Plus, now that texting and driving is outlawed here in Indiana, I'd hate for a cop to mistake me for texting when all I was doing was hitting the next song.

I just invested in a small iPod Shuffle. No screen, easy to learn buttons. I load it up with some songs and listen away. Cheap too. I think 4gigs is like $50 or something..

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Ok, I just looked it up. In a 90-93 setup, the cable harness has two connectors on the CD player side:

BLACK connector C1:

- 7 Green/white stripe - Mute output (input to radio)

- 8 Brown/white stripe - LH audio output

- 9 Green/white stripe - RH audio output

- 10 Black/white stripe - Low ground (audio)

- 11 Yellow - BAT

- 12 White/black stripe - Disc ON output (input to radio)

- 13 Bare ground - (audio shield)

- 14 Black - High ground

- 15 Red - Power ON input (output from radio)

WHITE connector C2:

- 1 Black - Ground

- 2 Grey - Panel light

- 4 Green - E&C bus

- 5 Purple/white stripe - VFD dimming

Padgett, is the diagram you posted for the tape player side? If so, it seems to correlate with the black connector on the CD player. The other connector is for lighting and the E&C bus connection (which I bet isn't really needed.)

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Step 2: I looked at the tape player from my '90 Regal. (I installed a DIN sized aftermarket stereo in the car some years ago. It fits in the opening that the tape player used. So the original tape player is sitting on a shelf in my garage.)

The white and black connectors are the same. However on the black connector, there are two rows of pins - one row is used for the cassette deck, and the other is used for the CD player. So it certainly seems like repinning the connector is all that is needed to just plug 'n play. Since I don't have a '88-89 Reatta, I should probably try it in my Regal...

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Step 2: I looked at the tape player from my '90 Regal. (I installed a DIN sized aftermarket stereo in the car some years ago. It fits in the opening that the tape player used. So the original tape player is sitting on a shelf in my garage.)

The white and black connectors are the same. However on the black connector, there are two rows of pins - one row is used for the cassette deck, and the other is used for the CD player. So it certainly seems like repinning the connector is all that is needed to just plug 'n play. Since I don't have a '88-89 Reatta, I should probably try it in my Regal...

YES! You rock. Please let me know if you can test it. I was noticing the white/black pin combo on only Reatta CD players on Ebay but couldnt see the detail in the pinouts. The later ones only seem to have a single black pin. I wonder if I could just buy a single black CD player and just relocate the white pins into the black one.

Edited by SeanR
I own page 2. ;) (see edit history)
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Padgett: I used the American International GMK210 kit: American International GM-K210 (gmk210) Single DIN Installation The stereo protrudes an inch or so, but the install kit covers it.

I had to use a 90 degree on the antenna lead to get clearance. It also needed a short extension cable with an adapter. More interesting was that I wanted to keep the old control panel active so that the clock display would work. So I fashioned a 3-way harness, which included a 'reverse' connector, to keep power to the old Delco remote box. Of course there are no audio connections to/from the old box anymore.

I wrote up some notes on it at the time. If anyone has a '88-'94 Regal and wants a copy, PM me.

Sean: Not sure when I would have time to try it, and the only slave player I have that actually plays CDs is already in my Reatta. So don't wait for me. Also note that the slave CD player from that generation always has two connectors on it. (At least the ones I have seen.) If you are looking at later Delco slave units, from '95 or so onwards, they are controlled from the head unit. So the electrical interface is very different. They won't work.

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... I wonder if I could just buy a single black CD player and just relocate the white pins into the black one.

A couple other things: You might want to contact Jim Finn (or one of the other parts suppliers around here) before bidding on a random, unknown quality, ebay item. Jim has stated here before that he has a bunch of the players sitting on his shelf - some working, some not working.

Also be really careful when repinning the connector. There is 12v on some of the wires, so getting a pin wrong could be a disaster.

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Padgett - I was just looking at the 89 FSM, (chapter 8, frame 150-4), and the pins on the tape player are somewhat different than the schematic you posted above. So I would caution anyone trying to do this to carefully compare the '89 and '90 FSMs.

The E&C bus is a shadow of its former self in the '90 configuration. Since there is no CRTC, the only connections are between the head unit, CD player, and the OBD connector. It would be interesting to know how much actual communication there is between the head unit and the CD player. I bet not much. For example errors are displayed on the CD players display. So even in that case, the head unit does not seem to be very involved.

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Interesting. The 89 FSM shows C1 and C2 while the Delco Radio manual shows a single row. Internal and external ?

Dunno.

Here is the relevant page from the 1990 Regal FSM. Might be hard to see, but it shows the same pinouts for all three slave units that were offered that year, i.e. tape, tape+equalizer, CD. The pinouts on the slave unit shown are identical to the Reatta slave CD drive. I'm not sure this is entirely accurate as my tape player seems to use the other row of pins (1-7).

7520-1990-regal-fsm-page-8a-150.jpg

Cropping a bit:

7521-1990-regal-fsm-8a-150-2.jpg

Edited by wws944 (see edit history)
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... I'm not sure this is entirely accurate as my tape player seems to use the other row of pins (1-7).

Nope, I am wrong. The Regal tape player does use the same pins as the Reatta CD player. In this photo, the CD player is on the left, and the tape player is on the right. Note that in both cases, the only pins present are the upper row by the connector keys:

7522-1990-buick-slave-connectors-reatta-riviera.jpg

Here is what both units look like from the front:

7523-1990-buick-slave-units-reatta-riviera.jpg

So I guess the real question is whether the Reatta tape player uses the same pins, or the other arrangement that the 89 FSM shows. Either way, it seems that the CD player could work.

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