Radio Schematic

[Guest The Goggi]

OK I was hanging out in my trunk when I happened to look at the speaker magnet. Printed on it was 10ohms. That would make a crossover of about 100 hz or so with a 100ufd ... the 4 brown ones. If you were to put aftermarket 4 ohm speakers that would make around 250hz rolloff which would be a dramatic difference. That would cut out almost all of the bass instead just the lower omnidirectional part.

It's starting to make more sense I think.

Check that schematic again please and ease my mind... that has to be the bass rolloff circuit.

Appreciate your efforts.

Edited August 4, 2009 by The Goggi (see edit history)

[handmedownreatta]

the front ones are 4 ohms...

[Guest The Goggi]

Well, so much for that theory.

Hmmmmm.

[handmedownreatta]

could be that the front speaker and tweeter are series wired...

[Guest The Goggi]

I thought that also, but I will reserve that opinion for when I have something to back it up. I have finally got access to the online prints and they are a bad scan... hard to see some of what I think is relavent. I am expecting my packet any day now. The 4 caps 100uf are in the signal path, but it is questionable as to the role they play. They may be a gain adjustment as has been suggested. I could very well be mistaken as to their function, but I am not totally convinced. I am though pretty convinced that the preamp takeoff is accurate in the 19, 20, 21, 22 pins in the tuner chip to bypass the amp circuit. I will follow up that theory in a few days after a more thorough review of prints in hard copy. Seems a fairly easy operation.

I may need a little anesthesia though.

Crown Royal is my anesthesia of choice ... yours?

[D-a-n-i-e-l]

OK, I have been messing around with a couple radios that I have. There is a circuit called the DDL ( dinamic distortion limitting) circuit. If disconnect it suts off. So what if I remove the caps, determained to be the filters, and parralle an other amp chip to the exsisting chips. Would this allow me to use the second chip, of better quality, without rolloff?

[Guest Mc_Reatta]

Yes, if the caps in the signal path between the preamp chip and the power amp chips are the source of the unwanted roll off. Best way to find out is for someone with a spare radio and some skill with a soldering iron to try it out. Another option is to get a box like the Audio Control LC6i and use it to clean up the speaker signals and put them back into a seperate amplifer

[handmedownreatta]

i have a broke 89 module i could donate...

[D-a-n-i-e-l]

LC6 is a great piece of equipment (the best so far) but does not help on the rolloff.

[D-a-n-i-e-l]

Bump, any progress?

[Guest The Goggi]

Talked to Delphi ... he had to email the office up north? to get info on the IPC ... apparently another plant handled that unit. He is waiting for a response from them. He hopes to get me something soon he says . Was waiting to send a complete package, so has not mailed any of the radio stuff yet. The numbers that Padgett sent me were good , just waiting on a response.

Will keep you informed.

[Guest The Goggi]

Spoke with Greg Moyers from Delphi today and he has an entire package together of everything he could find. He said he is waiting for a respose from the other plant in Auburn Hills that has some info on the IPC.

He told me a story:

Don Almquist, former CEO of Delco ( he's in his 80s) brought his red/tan '90 covertable in to service the radio. Apparently he did not want to take it anywhere else because he had a 6 disc changer modded into the system to work through and controlled by the head unit. Turns out the radio is making popping noises and need the 6 green caps replced (referenced @ Reatta Owners Journal - Radio Capacitor Replacement Instructions).

Apparently he was so impressed by the car when he bought it new that he invited all of the assemply line signers of his book to dinner and took pics with them.

He is supposedly looking to sell his car. It has 14k miles and has only been driven seasonally at his FL summer home. Has been put on blocks every season and has the original tires. I begged him to email me the info after he talks to Don. I would really like to talk to Don in regards to the development of the systems since he was CEO at the time. I can't afford the car but I told him that I would like to post it here to generate interest.

It was a second hand conversation ... I did not speak with Don personally but I hope to. I keep getting more excited everytime I talk to him. I hope this doesn't go bust ... I have a lot of time invested and Greg Moyers has been very nice.

Just an update. I will continue as I get more info.

[Guest Richard D]

I would love to have any schematic for a Reatta, the CRT, the touch screen, all radio components even the VFD for the 90 and 91 dashboards. I would be happy to share in the cost of getting any of these.

Thank's

Richard

[D-a-n-i-e-l]

The 90' would be easy to mod for a disk changer. The hard one is the 88/89.

[DAVES89]

Any progress?

[Guest The Goggi]

Just an update:

Regretfully, I have yet nothing to show for my efforts. I continue to call my contact at DELPHI to no avail. He has been very good about speaking with me and promissing me the world but no dice yet and he has recently and suddenly been impossible to reach.

I hope I am not being brushed off.

I am embarrased at the excitement I showed to the forum only to still have nothing in hand.

I continue to try and have access to a large format scanner so if anything comes through I will be very excited to share any and everything I get digitally.

I hope as I am sure all of you do that the efforts will provide fruitful.

Dissapointed but not beaten,

[D-a-n-i-e-l]

any good with communication busses? I have been thnking about building my own Radio brain, but I do not know how to progam/write the communication bus.

[Guest The Goggi]

I have recently been transfered as Project Manager to another hospital and have access to some techies in the Biomed department. They only repair biomedical systems. Their knowledge seems to be limited to biomed but I like to brainstorm with them. They understand electronics in general and are pretty smart.

Funny you say that because I have thought about redesigning/building a radio based loosely on the original.

I'm sure that I am crazy, but I bet it could be done to control whatever we wanted.

I still would like to find someone that knows how to write code for the CRT. I believe it is a form of BASIC but have no way to read it.

[handmedownreatta]

hd radio with on screen band name and song would be wonderful...

[Guest The Goggi]

Hello all,

Sorry so long but I have, at least a little, good news.

I received a partial package that includes:

1988 Auto Service Manual (dated Sept. and Oct. 1987)

covers: Buick, Olds, Pontiac, Chevy and Cadillac Alante'

Full specs and schematics for all radios and tape decks

also

Delco Electronics 1988 New Products School Manual

covers everything you could ever want to know about the radios and how to fix them.

There doesn't seem to be anything about any programing, but does talk about CD players a bit (I'll have to look more closely).

I am doing my best to get them scanned and I would like to get the information to someone who would post it on their site (Padgett, Daniel?)

I am hopeful that I can find someone with extensive circuit knowledge to work with me on some really good mods (ie input without the use of the tape trick ... preamp outs tapped in before the built in radio amplifier and "filters")

I am still working on more info for the IPC and possibly 90-91 models but no luck as of yet.

Please be patient with me as this is a "plethora" of info and will take some time and money to get it all scanned. That being said, I would like it posted where we can all access it. Please let me know how to do this. I would be more than happy to send someone a CD, but I am not in the business of shipping CDs so one or two will have to be enough.

Daniel ... I am excited that we may get some insight to add upon your mods. I'm looking forward to what you may get out of them.

I'll get them as fast as I can.

Peace.

[padgett]

I'd be more than happy to help, what do you need ?

[D-a-n-i-e-l]

I hope you make some progress on it. I am in the process of trying to teach myself hexa decimal to help figure out the communications on it. This is only the tip of what it will take to build my own radio brain.

[Guest The Goggi]

I'll scan the small stuff this week and send it to ?

The big stuff (schematics) I want to scan on a large flatbed. My contractor can do large fullsize blueprints at a cost so I will have him do the large stuff in single scans.

Who runs the Reatta.net ? Reatta Owners Journal ? I guess those would be the places to put this. Suggestions?

I was under the impression that it was a form of BASIC. Not sure where I got that from.

Edited January 5, 2010 by The Goggi (see edit history)

[padgett]

a) count on fingers and toes. Do not count thumb or big toe

each limb is a digit (nibble), two are a "byte"

Could also get a TI Programmer or set the Windows Calculator (Calc) to "scientific".

I used to write programs in executable ASCII.

[wws944]

a) count on fingers and toes. Do not count thumb or big toe

each limb is a digit (nibble), two are a "byte"

Could also get a TI Programmer or set the Windows Calculator (Calc) to "scientific".

I used to write programs in executable ASCII.

You had ASCII? Luxury. Real Programmers punched absolute binary code onto card decks. (After toggling in the bootstrap program on the front panel.)

Seriously, these radio manuals and schematics could be very interesting. Can't wait to see the scanned versions!

Edited January 5, 2010 by wws944 (see edit history)

[padgett]

Bootstrap toggle on a PDP was in octal. We were talking about hex.

[KDirk]

This may be off topic, but-

binary on punch cards? Ugh. Octal is very little better, I always found it hard to think in base-8. Hex came easier, but still took a lot of getting used to. You guys who did the programming on early systems like Padgett is referring to were the real men of the computer business. I don't think I could have cut it.

I fear we who like to program have gotten all flabby and lazy with the use of advanced compilable languages and visual development tools that are the preferred avenue now. Since there is no longer a need to conserve system resources (memory and mass storage are dirt cheap and easily expanded) there is no longer a need to be accomplished in the true art of [tight] coding.

If it gets all bloated and incomprehensible, so what (Windows 7 anyone?). Just require a faster CPU with more cores and more RAM and cover your sins of ineptitude with the increased performance. When that doesn't solve the problem, deflect criticism by announcing the next release 3 or 4 years early. Everybody gets excited for vaporware ya know.

Of course, this all rings true of any human pursuit - when people don't have to try to do better, they just won't.

Getting back on topic now, I will be interested to see the info that Goggi did finally receive. It would be nice if some info on the IPC's at least could also be obtained. The real prize would be info (or at least service data) on the CRT and CRTC.

Here's a thought, since it is now Government Motors, perhaps we can file a freedom of information request for the interface and specifications on these systems. Then again, when we get the copies, 98% will probably be redacted due to the TSA using Reatta touch screens for airport security management.

I think I need to go relax a while...

KDirk

[Guest Mc_Reatta]

Daniel, Since it was an 8 bit byte computer you need to know octal not hex. You really need to know the instruction set for the processor. Try to find an old programmers guide for the 6809. A google search on 6809 assembly language programming turned up some hits. Without some help from GM you may not ever know all of the instructions in the instruction set as they would have enough pull to have special undocumented instructions made just for their use. I used to do some assembly language programming on 8088s which were 16 bit and used hex and without the source program and developers notes it could be a real bear to reverse engineer things.

[padgett]

And the GM computer uses a Motorolla 6809 (8 bit 6800 with hardware multiply and divide).

Bytes can be 4, 5, 7, 8, or 9 bits, the original definition was the number of bits needs to express a character. (I also spreken baudot, EBCDIC, CCITT2, TEKHEX etc). As to age let us just say that I learned FORTRAN before the IEEE was the IEEE.

The bootstrap toggled into a PDP-8 was expressed in Octal because that was how the keys were laid out and all you need are decimal numbers (0-7). However each octal character only uses three bits which does not divide into eight or sixteen. Keep in mind that the whole mess with character sets began with Herman Hollerith and the 1880 census with many ded ends along the way.

[wws944]

Well... The PDP-8 was 'naturally' an octal machine due to the layout of the opcodes (3 bits) and such in its instruction words. A character on the PDP-8 was either 6 bits or 8-in-12. There wasn't a natural byte size, other than 12. "Byte size" was not necessarily the same as "character size" back then. (FWIW, the first computer I ever programmed was a PDP-8/I running TSS-8.)

The 6809 is 'naturally' programmed in hex. If you look at the instruction opcodes, register set, and layout of the special registers, it would be very strange to do things in octal.

It's kind of funny, but I have a much easier time with octal than hex. Guess it is in my pre-VAX roots.

[padgett]

or a lack of sixteen fingers...

[Guest Mc_Reatta]

I found a copy of the instruction set for the 6809E at:

http://www.6809.org.uk/dragon/6809e.txt

Indeed it is programmed in dual caracter hex. Believe the difference in the E varient is the internal clock is missing.

Since this chip was used in the Rat Shack TRS 80 Color computer as well as others, there is quite some information still available. There are even several emulators available, so Reatta programs could be run on more modern computers if the proper input and output interfaces were made. (Not an easy task either)

[padgett]

You can set up simulators for the inputs. Couple of years ago I sent out a few CDs with all of the ECM/BCM information that I had collected (both are 6809 based) which included the instruction set and the boot process/initialiation plus quite a few of the Reatta "5B" bins and a couple of disassembiles. I may still have it if someone is serious about digging into it (never got any feedback from the originals I sent out).

[Guest Mc_Reatta]

Does anyone know if there would be an interface available in any of the scan tools that would convert the Reatta data bus signals to RS 232? That might make is simpler to get the data to and from a computer running a 6809 emulator. Then you would need the source code for the CRTC.

[padgett]

This may I had an earlier version that could capture the raw signal.

[Guest The Goggi]

I have The 1988 Delco Electronics New Products School Manual scanned into PDF format and I would like to get it posted to "Reatta.net":cool:

Can someone direct me as to how to get this accomplished.:confused:

I tried to add as an attachment but the files are to large.:mad:

Due to permissions, I would like to try and be at least concientious enough to put it with the other info under password on "Reatta.net"

I am still working on getting full size color scans of the schematics ... bear with me.

[Guest The Goggi]

Well, I have sent the info to Reatta.net to be posted. As I am reading through all this info, I realize that this will be quite the resource for those that understand it (I only get a little of it).

It does show all of the different cars that use the units. The same units 1 w/ eq and 1 w/o eq were used for most of the GM cars and trucks. This should answer most of the "what other radios will work" questions.

Can't wait for you guys with the knowledge to let me know what you think. D-A-N-I-E-L check out page 44 when you see it.

Hope this helps.

[KDirk]

Goggi-

Besides Reatta.net, perhaps this info should be also be submitted for inclusion on Ronnie's site:

reattaowner.com

Probably helpful to have this info on both sites so if one is offline/unavailable for some reason there is a "mirror".

Just a suggestion.

KDirk

[Guest Mc_Reatta]

Goggi, Thanks for getting the information and getting it posted. I'm sure a lot of us will have fun looking it over and coming up practicle with uses for it.

Padgett, That cable does look like what would be needed. Run that into a computer running the CRTC program on a 6809 emulator and you should be able to duplicate the function of the CRTC outputs anyway. If the cable runs both ways, there should be a way to use the keyboard to simulate the inputs of the touchscreen so that you could operate the inputs as well.

Thinking about playing with this pleases the mind, wish I could convince my wallet and clock to go along for the ride.