Q: 590-0790-A adapter for Multiscan 15 "Monitor

loyle,

Any good used computer store should have them.  I support computer recycling shops.

Here is a link that shows newer adapters:

http://support.apple.com/kb/ht3235

I am still looking for the fifteen year-old knowledge base article that shows what you are looking for.

Jim~

It was linked at the bottom of the page!

http://support.apple.com/kb/TA23337

Oddly enough, the chart does not list the 15 inch multi-scan display.  The adapters listed for the 17" ms should work as well.

Here is a sample of a vendor but they are out of stock.  No wonder at twenty five cents.

http://www.geeks.com/details.asp?invtid=F3H963

If you google with:

macintosh video adapter Cable, Adapter, 15-pin 3 row to DB-15

you can narrow your search.

Good luck

Jim~

If you can find this adapter, it's better than the one that Jim linked at geeks.com.  The 10 DIP switches provide greater compatibility.  The declining demand for this product may make it more difficult to locate than in previous years.  I assume that you're trying to plug the MultiSync's display cable into a newer Mac with a VGA-ported display card.  In this case, the adapter doesn't change the gender of the connection.  It accepts the male DB-15 Mac display plug, converting it to a male VGA plug.

Turns out you will not need either one of the adapters we suggested.  What you need is the Cable, HDI45 to DB15, Display Adapter.  Visit this site to take a look at it:

http://support.apple.com/kb/TA23337

The 15" MS monitor will plug right into the LC 475.  The 6100/7100/8100 series of computers adopted a different high density monitor connection.  If you look at the top adapter, Cable, Adapter, 45-Pin, you will see all the components that were built into the HDI45 plug.  That octapus cable is the opposite of what you need for your multi-sync monitor.  Fortunately, that style of HDI died in one generation.

You said that the monitor on the LC475 is dead.  Maybe not.  First, look here to make sure we are talking about the same computer:

http://www.everymac.com/systems/apple/mac_lc/stats/mac_lc_475.html

Try this trick.  Turn the computer on at the power switch.  Leave it on for ten seconds to load the capacitors and all, then turn the switch off and back on quickly.  That might wake up the video circuit to the monitor.  Details on why later if you want to know.  A dead PRAM battery in a 610 or a 6100 will definately cause the monitor to not wake up.  But, rather than buy a new battery for a computer you never intend to use on a daily basis, use the on-off-on trick and save the five bucks for something else.

Yes you can network the computers if you want to go to that trouble.  Doing it 'headless' would not be easy.  You have to configure the network from both ends.  If the non-fruit colored iMac is new enough then you will not need a crossover cable.  It will auto detect.  If it is too new, you will have appletalk issues to deal with.

If you are near a large city with a Mac user group, you might just borrow a SCSI zip drive and a USB zip drive.  A platinum G3 would also be nice.  You can find them for $5 at recyclers.  The original G3s will take both SCSI drives and IDE drives in the same case.

Options abound.  If you are going to buy an ethernet cable, it means you do not have one.  Explore other options while you are at it.  If you are in the NW, we can give the name and street address of where to buy cables for $1, zip drives for $2 and G3s for $5.  Good luck.

Jim~

The display adapters have three ID bits that are powered, grounded or wired together to identify [to your Mac] the capabilities of your display, and allow the Mac to choose sensible resolutions. You may need the adapter for a few minutes to turn on File Sharing.

If you have a home Router of almost any description, you can connect everything up there and skip the crossover Ethernet cables and use all straight cables.

The LC475 probably does not have Ethernet capability, but you can use diskettes to the 6100 and go from there.

Grant,

I have never torn one of those adapters apart.  Know of any descriptions or schematics?  Might be nice to study that further.  Thanx.

Jim~

This document cover the original Mac II era equipment. I strongly suggest you print off a paper copy and archive it yourself:

http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_08.html%23//apple _ref/doc/uid/DTS10002477

This document is the best at describing the method behind encoding used in later beige Macs:

http://developer.apple.com/legacy/mac/library/#technotes/hw/hw_30.html%23//apple _ref/doc/uid/DTS10002499

This note seems much less helpful, but addresses specific monitors:

http://support.apple.com/kb/TA21618

The movie version:

Principle 1) to run a VGA monitor, you need Red, Green, Blue, H-Sync, and V-Sync. These must be on specific pins and are not negotiable.

Principle 2) to get that Monitor to work with a beige Mac, you need to provide the correct sense codes at startup. The dip-switch adapters change the connections on ID bits on pins 4, 7, and 10 to produce the right codes at the Mac.

Thanx, Grant

Just the detail I was looking for to have on file.  We have always had monitors to swap out until we found one that worked.  Now I might just go back and play with some of the obscure monitors and nuBus cards.

Jim~

The edit option expired. 

This article shows the pin assignments for an adapter to sense properly:

http://support.apple.com/kb/TA21607?viewlocale=en_US

Thanx again.

When you work through all the permutations in ALL the articles, you start to notice that although there are a ton of possible codes, most of them are for displays that will never be seen again.

There is one more adapter that ought to be immortalized with this group. The one for the Blue & White G3 to use an older monitor. It uses an available Voltage (the "ground" from a low-going sync signal) to tell the Blue & White that it ought to look at the pins as ID bits, not as a DDC "side channel" that can be used to discuss the display's capabilities

loyle wrote:

" I own a LC 475 (the monitor is dead)"

Not quite to the point of your question but, FWIW, if the 475 makes all the normal startup chimes and whirring, but the display remains black, it can be something as simple as a dead PRAM battery and NOT the monitor. That model and a few others will display no video when the PRAM batery is dead.

I nearly bought a new monitor for our P475 when it did the black screen thing years ago. Fortunately, I found an Apple reference to this while looking for something else.

Here's the Apple article on the subject (note that 61XX models are also so affected by a bad battery):

http://support.apple.com/kb/TA35928

Have you tried the monitor from the 475 on another older Mac?

PS: Hi, Jim! Is your e-mail working?