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Commodore C-128 on 1084 monitor - possible to do both CLA and RGB modes??

legendre

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Jan 24, 2014
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I just came across a Commdore 1084 monitor - funny, I wasn't even aware of the model. Must have missed it way back when..

Anyway, this monitor has several different video input options. It will accept (among others) C-64 type S-Video (C / L /A) and two different modes of RGB (it seems).

So if I'm using a C-128 - I know it's possible to cable the "standard" DIN video port on the 128 into the C/L/A input on the 1084. That works just fine. But is there a way, simply with the correct cable, to also connect the 9-pin RGB output on the 128 to one of the (DIN) RGB inputs on the 1084?

See, as it sits, I have two monitors connected to the 128 - one 1702 on the DIN video, and an RGB monitor on the Din-9 RGB port. I'd like to just use the 1084 - and be able to switch video modes on the monitor rather than use two different monitors.

So does it work? Has it been done?

Thanks!
 

GottaLottaStuff

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Just get a 9 pin D-sub on each end cable to go from the 128 to the 1084. The 1084 was made for the 128. Once it's all wired up, you can push a button on the front of the 1084 to switch inputs.
 

commodorejohn

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Yes, the 128 can drive the TTL RGB input on the 1084; you just need an adapter cable. They're not terribly common, but if you want to hack one up yourself, there's information on pinouts and wiring here.
 

legendre

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Just get a 9 pin D-sub on each end cable to go from the 128 to the 1084. The 1084 was made for the 128. Once it's all wired up, you can push a button on the front of the 1084 to switch inputs.

That's the issue - The 1084 doesn't have a Sub-9 connector on it, just a pair of DINs.

Next poster seems to have the cable data, so I'll look at that now.
 

legendre

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Yes, the 128 can drive the TTL RGB input on the 1084; you just need an adapter cable. They're not terribly common, but if you want to hack one up yourself, there's information on pinouts and wiring here.

Thanks, this is what I think I'm looking for. But I'm hitting another question..

Is it just me, or is the DIN-8 jack on the 1084 (RGB TTL) input a slightly different pin-pattern than the DIN-8 used for video-out on a C64 or C128? On one, the outer pins form a "U" shape - whereas on the other, they form more of a "C" shape.

Isn't the whole point of DIN "Deutsch Industrial NORMS"? As in, normalized - as in, predictable? =P

ETA: Being the big spender that I am, I went ahead and ponied up $1.98 for two of these: http://www.ebay.com/itm/290571600803 <- They seem like the correct pattern for the port on the 1084, they're the "C" type. Did I get that right?
 
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legendre

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Man you guys are confusing me!

One DIN is for the C128's digital RGB. The other DIN is for the Amiga's analog RGB.

Hence, the difference in pin-out "shapes",
Robert Bernardo
Fresno Commodore User Group
http://videocam.net.au/fcug

Actually, the two DIN female connectors on my 1084 differ by far more than just the pattern..

On the back of the 1084 monitor, the "TTL RGB" connector is an 8-pin DIN, whereras the "Lin RGB" connector is a 6-pin DIN. The "different" 8-pin female DINs I was discussing are the one found on the 1084 (TTL RGB) vs. the one found on the C-64 / C-128 (Composite / Chroma / Luma / Audio).

So did I buy the correct connector to tween the C-128 RGB to the 1084 RGB? I want to connect the DB-9 female (RGB) on the C-128 to the TTL RGB connector on the 1084 - correct? I mean, as opposed to the Lin RGB on the 1084 - which is a 6-pin?

ETA: I guess I don't know the diff between Lin and TTL RGB.. I know that TTL is "Transistor-Transistor Logic", so that must be some kind of digital signal.. but what is "Lin RGB"??
 

commodorejohn

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Yes, you want to connect the 128 to the TTL RGB socket - the Lin RGB is for analog RGB signals such as you get from an Amiga or an MSX2 or somesuch.

There were a lot of different versions of the 1084, so some confusion is to be expected.
 

legendre

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There were a lot of different versions of the 1084 (...)

In the great tradition of home computer hardware, I suppose it's simply too much to expect a version rev, much less an actual model number change.. or even an A/B suffix.. ;-)

So in the case of x86 PCs, where we have the legacy of CGA, EGA, VGA and ultimately SVGA color video formats - are these analog or digital signals, or a mix of the two over the years?
 
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carlsson

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Yes, the 8-pin DIN is available both as 270 degree "C" shape (more common) and 262 degree "U" shape (a bit hard to find). However everywhere I look, I find more and more applications using the "U" shape: the C64/128 video out, the Genesis RGB out, even my Olivetti PC-1 turned out to have analog RGB in an "U" shape. The cassette port on MSX etc is "C" shape though, and of course the TTL RGB input on your 1084.

By the way, I believe the 1084 series as well as other Commodore monitors were OEM products, e.g. the 1084S with stereo and DB9 input seems to be mostly identical to a Philips 8833, and the earlier models with DIN inputs and/or SCART in some cases (Europe) seem to have matches among other, often smaller monitor brands. That would suggest that Commodore contracted out production of monitors to various parties, and didn't put too much effort in keeping model numbers apart. I know prior to the 1084, there were at least 1080 and 1081 models too, not counting the 170x, 180x and 190x series which also come in some variations.
 

KC9UDX

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1084 monitors were made by several sources, at least, Philips and Daewoo, maybe more.
 

dano

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For what it's worth, I ordered some 8 pin DIN connectors to make C64/128 video cables for our club members. Only when I got them, I discovered they were the more common "C" shape. My first thought was to exchange them, but I wasn't having much luck finding the correct connectors to replace the. After a little more investigation, I noticed that the two end pins are used for modulator power and audio in, neither of which I needed, so I removed those pins from my connectors by pushing them through the plastic with a soldering iron tip. The remaining 6 terminals provide all the needed signals for composite, chroma, luma, audio, and ground.
 

billdeg

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I just came across a Commdore 1084 monitor - funny, I wasn't even aware of the model. Must have missed it way back when..

Anyway, this monitor has several different video input options. It will accept (among others) C-64 type S-Video (C / L /A) and two different modes of RGB (it seems).

So if I'm using a C-128 - I know it's possible to cable the "standard" DIN video port on the 128 into the C/L/A input on the 1084. That works just fine. But is there a way, simply with the correct cable, to also connect the 9-pin RGB output on the 128 to one of the (DIN) RGB inputs on the 1084?

See, as it sits, I have two monitors connected to the 128 - one 1702 on the DIN video, and an RGB monitor on the Din-9 RGB port. I'd like to just use the 1084 - and be able to switch video modes on the monitor rather than use two different monitors.

So does it work? Has it been done?

Thanks!


That's what I do exactly. I can view all modes with one monitor and two cables. You just have to remember to hit the display mode button before you restart the system to go into a changed-mode state.
 

legendre

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Jan 24, 2014
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HERE'S THE UPDATE - TOTAL FAILURE IS MINE!

I received the DIN-8 connectors in good order, though they arrived almost a week later than the last estimated arrival date. Oh well, they were cheap..

I wired up a cable, using a spare factory-made DB-9 to DB-9 cable. One end was chopped off, so I could attach the DIN-8. I pulled pinout diagrams for both the C-128 VGA port (DB-9) and the TTL-VGA port on the 1084 (DIN-8 ). Made up a crossover cheat-sheet and soldered it all up.

Doesn't work.

What I get, is a mostly green screen, with what looks like it MIGHT be some very smeared / skewed lines of gray text near the top.. the standard boot message. There seems to be a total lack of vertical sync, and the screen is rolling horizontally. The "text" is totally illegible, but if I hit RUN STOP-RESTORE it's clear that it's trying to display the READY. message. So it's like all of the video lines are screwed up - but what the heck did I do wrong? Is it wired backwards?? Did I mistake gender or something like that?

Here is the connection scheme I used... please take a look, and please tell me I screwed it up somewhere:

Code:
[b]DIN-8 (1084)     DB-9 (C-128)[/b]

(1)                 NC
NC                (7) MONO
(2)               (3) RED
(3)               (4) GRN
(4)               (5) BLU
(5)               (6) INT.
(6)               (1+2) GND
(7)               (8) HORIZ
(8)               (9) VERT

I don't see the issue.. been over it and over it.. checked the cable, checked the docs, etc. Ack!!

Thanks for any help.

ETA: This is a real frustration. It took almost 2 hours to pull the data, come up with a translation scheme, cut / strip / trim the cable innards and then actually solder that DIN-8 up.. and I have major hand tremors, so it's double-trouble to work with stuff this small. I fear that the whole works is backwards - but I'm also in the dark about how to handle those two grounds - 1&2 on the DB-9. I just tied them together and soldered them to pin 8 on the DIN-8.

Also, the shields of the two connectors (DIN-8 and DB-9) are tied shell to shell via the cable shield and drain wires. So that should all be A-OK - right?
 
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jltursan

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The connections are 100% correct; so I can only think that you've made a mistake building the cable. Maybe you've mirrored the pinout?, it's a common error.

Another explanation can be a hardware failure like cold solder joints, the monitor VSYNC input can be loose or even the C128 having a bad output...
 

legendre

Experienced Member
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Jan 24, 2014
Messages
52
The connections are 100% correct; so I can only think that you've made a mistake building the cable. Maybe you've mirrored the pinout?, it's a common error.

Another explanation can be a hardware failure like cold solder joints, the monitor VSYNC input can be loose or even the C128 having a bad output...


Well you basically had it, sir. My workmanship was fine - I have the skill, experience and the wisdom to properly *question*, inspect and double-check it.. even when I "know" I have it right.

Turns out that I got bad connector gender info from some crappy web image. The handed pins on the DIN-8 (which would be 7,3,5 and 6,1,4) were swapped mirror-image. Apparently someone can't quite identify the difference between the M and F side of the connectors.. and I took their numbering as correct.

It works just great, now - after swapping around and almost making a mess of it. ;-) Thank gosh it wasn't a mini-DIN, or I'd have had to toss it and go with the backup connector!

Thanks for the help & guidance folks - I now have exactly what I wanted. C-128 in 128 or 64 mode (40 col) or 128 mode (80 col) on the same 1084 monitor. And it only cost me $0.98 + 1 used RS-232 / VGA cable + about 2.5hr of screwing around.

Schweet!! =)
 
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carlsson

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Nice! As for male or female, sometimes people list the pin numbers as seen from solder side and sometimes from connector side. Apparently a male connector from solder side has the same ordering as a female connector from connector side and vice versa. I'm not sure which order is the proper one, but I suppose it is good to point it out when one publishes a pinout.
 

legendre

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Jan 24, 2014
Messages
52
Nice! As for male or female, sometimes people list the pin numbers as seen from solder side and sometimes from connector side. Apparently a male connector from solder side has the same ordering as a female connector from connector side and vice versa. I'm not sure which order is the proper one, but I suppose it is good to point it out when one publishes a pinout.

Hello Anders,

Yes - and you've hit upon a MAJOR pet peeve of mine. Here's the deal with this..

Connector pin numbers are absolute, period - they are not relative to either gender or viewer's perspective. All one needs to know is the standard numbering scheme, and on which gender it is based. Once you have that, it's not a major intellectual feat to interpolate which is which when dealing with gender or mating side vs. solder / insertion side issues.

People create a lot of unnecessary confusion for themselves and others with these idiosyncratic descriptions. You often read things such as "numbering is for FEMALE connector from the SOLDER side" and so forth - when at the end of the day, Pin 1 is Pin 1 is Pin 1.. If you know the actual standard scheme, all the rest is just a pointless waste of time and trouble.

At a previous job, we built a product that used a 37-pin umbilical cable. Some techs would have no end of trouble, trying to figure out "Is that pin 12 for M or F, and from which end?!" - when both the M and F connectors were fully numbered - and on both sides! They just couldn't get it through their heads that the scheme is consistent and constant - just go with it, pay attention to what you're doing and it will work.

This time, in my case, I hunted around just trying to find a standard pin diagram for a DIN-8 - and boy were there a lot of hits. But all I could find were these M vs F / solder vs. mating things. So I went with one that looked well-done and clear - and even it was wrong!
 
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