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Mac LC and DB15 to VGA adapter problem...


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8 hours ago, Oberlehrer said:

I don't know if this is a question of adjusting or of monitor features. Sometimes certain older monitors work better with older computers than newer ones. I have an old Panasonic LCD monitor for such cases.

 

 

we tried on several monitors with different effects. maybe it's a matter of matching the frequency, after all, modern monitors and macintosh differ three decades...

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8 hours ago, dragon_x said:

maybe it's a matter of matching the frequency, after all, modern monitors and macintosh differ three decades... 

Both the IIsi and the LC475 output at 66.7 Hz; and here that particular monitor works with the LC475 at 640x480 (and a PM8100 and a PM4400) but not with the IIsi. My guess is a different sync type.

 

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8 hours ago, Oberlehrer said:

Both the IIsi and the LC475 output at 66.7 Hz; and here that particular monitor works with the LC475 at 640x480 (and a PM8100 and a PM4400) but not with the IIsi. My guess is a different sync type.

 

We will try to get Multisync or Multiscan monitor. it should be a solution. My friend tried to connect sometime ago LC to Multisync monitor and it worked... Unfortunately we havent any multisync monitor :(

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9 hours ago, Oberlehrer said:

I bought an old NEC EA190M a couple of weeks ago that also plays nicely with the IIsi. Those monitors probably cost close to nothing everywhere; I paid 15 € for mine.

Not in Poland. I jave checked CRT monitor prizes. We easily can find monitors for 10-15 euro but many prizes are between 1000-1300 PLN that is 250-350 EUR. Polish traders tries to earn as much money as they can...

Edited by dragon_x
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21 hours ago, Oberlehrer said:

The NEC I mentioned is a TFT, though.

https://www.ebay.pl/itm/NEC-MultiSync-EA190M-19-1280-x-1024-250-cd-m-5ms-VGA-DVI-Weis-Silber/302801275915

Sure, that's twice as much as I paid for mine. Still not too bad.

 

What do You think about that monitor?

https://allegro.pl/oferta/nec-multisync-ea191m-pva-dvi-vga-audio-9646225709

 

NEC Multisync EA191M , its a bit higher model that yours.

 

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I already have the LC at home :) What we have established: It makes a sound when it is started. After inserting a floppy, it tries to read it, and since I do not have a bootable floppy it ejects it after a while. I will try my hand at the db15-vga adapter, because there is no chance of getting the original one quickly. tomorrow I'll take pictures of the macintosh and upload it. I will also order the NEC EA191M monitor. There will be a keyboard to get but I'll wait until the computer is fully booted.

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Mac is already at my house. NEC EA191M monitor ordered. I will try when the monitor comes to build a DB15 to vga adapter. The housing is quite scratched. I found an offer to sell the case in much better condition but with rusty metal sheets after the battery ran out. If the mac comes alive, I intend to buy it and change the sheets. By the way, the housing has a rear cap and a speaker and fan housing, which I do not have.
The plans also include whitening the computer casing. If I manage to get the ram, I also want to expand the ram memory to 10 MB. currently it is 6MB. VRAM is probably 256KB. If so, I will be looking for 512KB of bone.
Such a renovation project promises to be.

Of course, there are also plans to replace the condensers. However, I have to find someone who will do it because I don't feel like soldering in smd.
Hope I can count on your help and advice?
Does it make sense to post a thread about the renovation of this computer?

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I don't think I've seen such an LC "in the flesh" myself so far; the ones I've seen always had the (unused) cutout for a second floppy drive. So it seems Apple made a case revision at one point.

I'm only mentioning this since you talked about buying a second case which seems to be constructed different. Make sure that the parts are really compatible.

Other posters will probably know more about the different LC revisions.

 

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This is the second generation of the LC.

 

the first had provision for another floppy drive, or two drives and no hard disk. 

And yes, first units had a different layout for speaker and fan. 

No problem swapping casing around though. 

Capacitors are leaking for sure, can see it from your pictures. 

 

Wash the board first, to remove goo. 

 

 

 

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8 hours ago, Oberlehrer said:

I don't think I've seen such an LC "in the flesh" myself so far; the ones I've seen always had the (unused) cutout for a second floppy drive. So it seems Apple made a case revision at one point.

I'm only mentioning this since you talked about buying a second case which seems to be constructed different. Make sure that the parts are really compatible.

Other posters will probably know more about the different LC revisions.

 

The case I found looks like in the attached photos. To be honest, I like mine better, without a second cut to the disk drives. However, I am irritated by numerous scratches and scrapes.

IMG_20200906_172331.jpg

IMG_20200906_172359.jpg

IMG_20200906_172213.jpg

IMG_20200906_172217.jpg

IMG_20200906_172228.jpg

IMG_20200906_172336.jpg

Edited by dragon_x
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8 hours ago, bibilit said:

This is the second generation of the LC.

 

the first had provision for another floppy drive, or two drives and no hard disk. 

And yes, first units had a different layout for speaker and fan. 

No problem swapping casing around though. 

Capacitors are leaking for sure, can see it from your pictures. 

 

Wash the board first, to remove goo. 

 

 

 

what is the safest method to wash the board?

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8 hours ago, dragon_x said:

unfortunately not. I am locaded near of center of the country...  

Yes, the "Pomeranian" part gave this away somewhat.

Anyway, I've recapped a IIsi, a Performa 475 and an SE/30 so far; so if everything else fails it would at least not mean shipping the machine around the globe...

Another thing: I think without the VRAM upgrade the LC supports only 512 x 384; not sure if the NEC will play nicely with that. I know that the NEC can do 640x480 without a problem.

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8 hours ago, Oberlehrer said:

Yes, the "Pomeranian" part gave this away somewhat.

Anyway, I've recapped a IIsi, a Performa 475 and an SE/30 so far; so if everything else fails it would at least not mean shipping the machine around the globe...

Another thing: I think without the VRAM upgrade the LC supports only 512 x 384; not sure if the NEC will play nicely with that. I know that the NEC can do 640x480 without a problem.

from what I read from 256kb the mac supports 640x480 but with a small number of colors. the picture should be on the screen. I'm looking for a 512kb vram sticks but unfortunately I found only 256kb so far.

 

from LC spec:

"*By default, the Macintosh LC only supports a single display, but a second one can be supported with the addition of an LC PDS video card. With the default 256k of VRAM, the LC can support a single display at 512x384 with 8-bit color or 640x480 with 4-bit color. Upgraded to 512k of VRAM, the LC can support 512x384 at 16-bit color and 640x480 at 8-bit color."

Edited by dragon_x
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16 hours ago, dragon_x said:

from what I read from 256kb the mac supports 640x480 but with a small number of colors. the picture should be on the screen. I'm looking for a 512kb vram sticks but unfortunately I found only 256kb so far.

 

from LC spec:

"*By default, the Macintosh LC only supports a single display, but a second one can be supported with the addition of an LC PDS video card. With the default 256k of VRAM, the LC can support a single display at 512x384 with 8-bit color or 640x480 with 4-bit color. Upgraded to 512k of VRAM, the LC can support 512x384 at 16-bit color and 640x480 at 8-bit color."

I actually just answered this same question about the LC and video resolutions elsewhere. 
 

I have an LC with only 256kb and I have a Multisync VGA video adapter that supports 640x480, 832x624, 1024x768 and the LC does indeed boot just fine at 640x480 and supports 16 colors (4bit). 
 

With 512kb of VRAM it supposed 256 colors at 640x480 and technically would support thousands if I had a monitor to display 512x384. 
 

Using the NEC Multisync adapter I note above I’ve not had any issues booting an LC on several different VGA monitors. 
 

Somewhere else someone mentioned the LC requires something like 25hz to boot but I’ve never found that to be the case. Not sure what I’m doing differently. 

Here’s some photos:

https://imgur.com/gallery/pD26RsQ

Edited by MrFahrenheit
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