The Elite 4/75cx has been disassembled. What happens if I remove one VRAM chip, will it boot with only 256kB video memory? One way to find out.

dj_pirtu wrote on 2023-03-10, 12:49:

I've been struggling A LOT with my MG-38606 motherboard with 486DLC. It has two problems: 1. RTC clock stops when powered of (i can live with that) 2. it gets unstable when warms up (i have swapped everything including cache-chips but nothing helps)

It has some Varta-stuff on one corner but nothing serious. But, I'll do full clean job any way to see if that helps. Yesterday I put the whole thing in vinegar overnight and today I'm gonna clean it as good as possible.

Let it get warm and gently touch the ICs and components on the board, see if any are getting hot, if you have a laser temp checker you could also use that or if you are lucky to have a thermal cam use that. It does sound like an IC/component is overheating and causing instability.

Today was a day of busts. Tried buying Republic Commando, early release with manual. Turns out it's already sold, the seller just forgot to take down the listing. But I'm getting a full refund.

I also grew unsure about the vintage market game seller guy. Checked the address I should go see the games on Google Street View and it looks like the kind of slum where people are lured in to be killed. All my instincts scream don't go there.

RandomStranger wrote on 2023-03-10, 14:49:

I also grew unsure about the vintage market game seller guy. Checked the address I should go see the games on Google Street View and it looks like the kind of slum where people are lured in to be killed. All my instincts scream don't go there.

Instantly reminded me of this...

Haven't had any "shady" trades, but being socially anxious as I am, I prefer the flea market and 0 interactions online shopping.

PD2JK wrote on 2023-03-10, 13:00:

The Elite 4/75cx has been disassembled. What happens if I remove one VRAM chip, will it boot with only 256kB video memory? One way to find out.

DSC_3051.JPG

TBH I don't think that is gonna achieve anything. If it's the low chip you pull it won't be looking high for it's basic RAM, if it's the high chip you pull it's probably just gonna be the same in basic modes, if it's either side of a large word then it will still be messed up. If the chips are full bus width then replacing low one with high one might get it working for everything that doesn't need more than 256k

BitWrangler wrote on 2023-03-10, 15:49:

PD2JK wrote on 2023-03-10, 13:00:

The Elite 4/75cx has been disassembled. What happens if I remove one VRAM chip, will it boot with only 256kB video memory? One way to find out.

DSC_3051.JPG

TBH I don't think that is gonna achieve anything. If it's the low chip you pull it won't be looking high for it's basic RAM, if it's the high chip you pull it's probably just gonna be the same in basic modes, if it's either side of a large word then it will still be messed up. If the chips are full bus width then replacing low one with high one might get it working for everything that doesn't need more than 256k

Thanks for responding, might as well replace them both then. Hopefully I can source some NOS chips somewhere.

PD2JK wrote on 2023-03-10, 17:30:

BitWrangler wrote on 2023-03-10, 15:49:

PD2JK wrote on 2023-03-10, 13:00:

The Elite 4/75cx has been disassembled. What happens if I remove one VRAM chip, will it boot with only 256kB video memory? One way to find out.

DSC_3051.JPG

TBH I don't think that is gonna achieve anything. If it's the low chip you pull it won't be looking high for it's basic RAM, if it's the high chip you pull it's probably just gonna be the same in basic modes, if it's either side of a large word then it will still be messed up. If the chips are full bus width then replacing low one with high one might get it working for everything that doesn't need more than 256k

Thanks for responding, might as well replace them both then. Hopefully I can source some NOS chips somewhere.

I don't know if it's just the picture, but the solder looking dull on the RAM side of the VGA chip is something I'd check out... sometimes and cold storage temps affect this, the solder starts to de-alloy, whereupon it cracks up easily and forms oxides, so just applying careful soldering heat down the side of that chip might do something.

I tested my model 35SX how it supports larger HDDs. Machine was originally sold with 40MB and 80MB HDDs and I was a bit afraid that IBM included some artificial limits to the HDD support. However, starter disk and auto configuration correctly recognized the 256MB CF card, so I'm pretty positive that this has the typical 500MB limit or so.

Besides the floppy drive, there seems to be very little shenanigans IBM did with this model and I already quite like it. This is a fun project for the spring 😀

PD2JK wrote on 2023-03-10, 13:00:

The Elite 4/75cx has been disassembled. What happens if I remove one VRAM chip, will it boot with only 256kB video memory? One way to find out.

DSC_3051.JPG

Reasons?

Cheers,

pentiumspeed wrote on 2023-03-10, 20:04:

Reasons?

Cheers,

Please take a look here.
Re: Bought these (retro) hardware today
Looks like the memory has gone bad, but I will inspect and try to resolder the legs first if that seems the case.

RandomStranger wrote on 2023-03-10, 14:49:

Today was a day of busts. Tried buying Republic Commando, early release with manual. Turns out it's already sold, the seller just forgot to take down the listing. But I'm getting a full refund.

I also grew unsure about the vintage market game seller guy. Checked the address I should go see the games on Google Street View and it looks like the kind of slum where people are lured in to be killed. All my instincts scream don't go there.

Shame. Good to talk about the busts though. I think newcomers to the hobby think we maybe go out of the house with our lucky horse-shoe and trip over a pile of vintage hardware at the first corner. Sometimes you get real lucky, most of the time you gotta grind for it. Though I have picked up 3 systems within 500m of my front step, none of them were very great, (775/775/754) one had been hit by a snow plow. Dude a block down the way had a few items at his yard sale once, forgot what I bought there though, think it was more modern.

edit: Think I bought my first HD6450 off him... but as I am remembering now, he had more stuff I wanted, but I was short on cash and there was another sale I was itching to go to across town, he advertised he was gonna be going until 2pm, and I asked him and he said he was gonna be out there until 2, so it being 9:30ish I went across town, stopped by the ATM, came rolling back up the street at noon-ish and he was packed up... either did a roaring trade or got fed up. So I never did buy anything else.

Munx wrote on 2023-03-10, 14:59:

Haven't had any "shady" trades, but being socially anxious as I am, I prefer the flea market and 0 interactions online shopping.

On the flipside, with online shopping you're at the mercy of the shipping carriers.

I just had to open two tickets today with our postal service, one for a no-show delivery and another that appears stuck in limbo for the past two weeks.

At this point, I'd rather meet with a shady character in a dark alley to buy this stuff. 😒

Hm. Since there is hope for DOS gaming with sound on (not too old) modern PCs since the release of SBEMU, I have acquired another Zbox. This one has a FX-7600 APU with Radeon 7 graphics, quad core. Not a powerhouse by any means but should do for DOS/XP/7 light gaming. What is most interesting about this box it that it actually has a serial port. Hopefully it's a real one. Raises the possibility of attaching an external MIDI module and using SoftMPU. https://www.zotac.com/us/product/mini_pcs/ma760-plus

Shponglefan wrote on 2023-03-10, 21:41:

On the flipside, with online shopping you're at the mercy of the shipping carriers. […]
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Munx wrote on 2023-03-10, 14:59:

Haven't had any "shady" trades, but being socially anxious as I am, I prefer the flea market and 0 interactions online shopping.

On the flipside, with online shopping you're at the mercy of the shipping carriers.

I just had to open two tickets today with our postal service, one for a no-show delivery and another that appears stuck in limbo for the past two weeks.

At this point, I'd rather meet with a shady character in a dark alley to buy this stuff. 😒

Buying from Germany and sometimes from USA is long than usual transit time. That's odd.

Right now I'm 2nd week waiting for my HP 800 G5 mini computer from USA and a stopwatch now in 4th week from Germany. I had stuff from Germany go through longer than usual transit time. Germany is not 3rd world and should had taken much less than that.

HP mini computer is small box and wouldn't weigh that much and can be packed decently in a small box.

Cheers,

pentiumspeed wrote on 2023-03-10, 23:53:

Buying from Germany and sometimes from USA is long than usual transit time. That's odd. […]
Show full quote

Buying from Germany and sometimes from USA is long than usual transit time. That's odd.

Right now I'm 2nd week waiting for my HP 800 G5 mini computer from USA and a stopwatch now in 4th week from Germany. I had stuff from Germany go through longer than usual transit time. Germany is not 3rd world and should had taken much less than that.

HP mini computer is small box and wouldn't weigh that much and can be packed decently in a small box.

Cheers,

If it's shipping from Germany via DHL, apparently they ship by boat. Usually my orders from Germany take between 4 to 8 weeks to arrive.

I've also had orders from the USA potentially take up to 8 weeks to arrive. I had one order keep bouncing around California for over a month before finally making its way to Canada.

Meanwhile, stuff from Eastern Europe or Japan often arrives within 1-2 weeks. ¯\_(ツ)_/¯

Shponglefan wrote on 2023-03-11, 00:05:

If it's shipping from Germany via DHL, apparently they ship by boat. Usually my orders from Germany take between 4 to 8 weeks to […]
Show full quote

pentiumspeed wrote on 2023-03-10, 23:53:

Buying from Germany and sometimes from USA is long than usual transit time. That's odd. […]
Show full quote

Buying from Germany and sometimes from USA is long than usual transit time. That's odd.

Right now I'm 2nd week waiting for my HP 800 G5 mini computer from USA and a stopwatch now in 4th week from Germany. I had stuff from Germany go through longer than usual transit time. Germany is not 3rd world and should had taken much less than that.

HP mini computer is small box and wouldn't weigh that much and can be packed decently in a small box.

Cheers,

If it's shipping from Germany via DHL, apparently they ship by boat. Usually my orders from Germany take between 4 to 8 weeks to arrive.

I've also had orders from the USA potentially take up to 8 weeks to arrive. I had one order keep bouncing around California for over a month before finally making its way to Canada.

Meanwhile, stuff from Eastern Europe or Japan often arrives within 1-2 weeks. ¯\_(ツ)_/¯

Interesting. The update just come late this evening after my supper, finally that HP mini PC is in Ontario, Canada and already cleared the customs. Yay!

Last year around spring, I lost a order of 120 765 cells from Germany for my hearing aids, so re0rdered again and got them way too long, was about 2 months. I was not paying locally since quality brand pack of 12 cells was about 20 cdn or so but now new one is less cells down to 8 cells for 17 and some change.

I'll keep sticking to ordering large packs of Power One 120 cells from Germany and they were excellent quality.

Cheers,

Shponglefan wrote on 2023-03-10, 21:41:

At this point, I'd rather meet with a shady character in a dark alley to buy this stuff. 😒

Well, i have actually done just that (!). 😱

This was a few years before I had much clue about the actual hardware - as in which models are good or sought after and such.
But I met this dude in a dark alley (sun had gone down, not much street lights there, and no people around), as that was his preferred meeting place for some reason.

He literally had the (very dark!) trunk of his car filled to the brim with various ISA sound cards, just lieing there 'naked' in a big pile. And I could pick whichever I wanted for free. Yes indeed, no money involved and ONLY loads and loads of soundcards!
(I suppose he was whittling down his hoard of stuff picked over years from recycling spots, and this time it was the sound card section)

So ignorant me just picked 1 of each I thought looked 'interesting' or strange, not knowing much about any of them. Is probably where I got my long red card from (turned out to be some Gravis Ultrasound).

Well the Radeon R6 AIW showed up.

Another tested DOA card. The thing is I actually believe them when they said its tested this time because the seller has multiple and appears to be a dedicated computer goods reseller. The 2 main 470 @ 10v caps seem to be vented, probably the problem.

Wiating to hear back on if the seller wants to do an exchange or refund, if he goes for refund and doesn't ask for it back I'll swap the caps then report back.

PD2JK wrote on 2023-03-10, 13:00:

The Elite 4/75cx has been disassembled. What happens if I remove one VRAM chip, will it boot with only 256kB video memory? One way to find out.

Fun fact. Depending on your model, this laptop can come with 512KB or 1MB of video memory.

Added a speaker to my newly acquired Walkman WM-FX40 by soldering it to two of the 3 pins on the worn out and broken headphone jack. So far, it works without issues.