I tried two motherboard repairs. Removed a KBC and replaced it with a socket on a 386SX motherboard. Made things worse, junked it.

Tried to troubleshoot a 486 board with no success, junked it.

Bad night.

I started playing through Star Trek 25th anniversary today, though I'm doing it through DOSBOX this time because of the MT-32 soundtrack being great, and my SC-55 not being able to properly replicate even the title song. Once I get to Judgement Rites, I'll be doing it in real DOS, since that game supports GM.

Replacement laser for my SCPH-1001 PSX didn't work, but I should have expected as much from gray market replacement parts from China. The laser positioning motor even fell out of the housing, and had no evidence of anything from plastic tabs, to adhesives, to screws holding it in. Even manually fixing it in place to test it didn't help, as it gave up trying to read a CD before the SCEA logo finished animating. At least I have a PSIO as a much more expensive option, but I wanted to use that with a different PlayStation.

Any good utilities for sprite-work/general graphics creation that work for MS-DOS? MIDI creation software? Just looking for recommendations.

RetroLizard wrote on 2020-11-13, 22:18:

Any good utilities for sprite-work/general graphics creation that work for MS-DOS? MIDI creation software? Just looking for recommendations.

I can't recommend anything specific, but there are loads of free or shareware graphics apps at http://www.lanet.lv/simtel.net/msdos/graphics.html and other Simtel mirrors. Editors, viewers, converters, etc

Okay. And what brand of AT-type Power Supply should I go with for a 486 build? Are there any good ones, or any way to recognize the good-quality ones?

RetroLizard wrote on 2020-11-14, 00:33:

Okay. And what brand of AT-type Power Supply should I go with for a 486 build? Are there any good ones, or any way to recognize the good-quality ones?

Seasonic, Enermax...

Actually I would go with anything that works and is in the 'shiny' case (the later, in the dull/matte one are usually crap). Make sure it's 200W, and check if the voltages are OK and you are good to go. If it dies - replace it. I'm yet to see (in my 30 year 'career' as PC user and system builder) a motherboard or a card killed by AT power supply going bad - and I've seen some going in flames literally with no damage to anything else. ATX PSUs are totally different animal though (and only real advantage of using ATX PSUs in the vintage builds over AT PSUs is that the high voltage is contained in the PSU's case).

Are there any ATX power supplies that have all the same rails AT power supplies do?

HanJammer wrote on 2020-11-14, 00:53:

RetroLizard wrote on 2020-11-14, 00:33:

Okay. And what brand of AT-type Power Supply should I go with for a 486 build? Are there any good ones, or any way to recognize the good-quality ones?

Seasonic, Enermax...

Actually I would go with anything that works and is in the 'shiny' case (the later, in the dull/matte one are usually crap). Make sure it's 200W, and check if the voltages are OK and you are good to go. If it dies - replace it. I'm yet to see (in my 30 year 'career' as PC user and system builder) a motherboard or a card killed by AT power supply going bad - and I've seen some going in flames literally with no damage to anything else. ATX PSUs are totally different animal though (and only real advantage of using ATX PSUs in the vintage builds over AT PSUs is that the high voltage is contained in the PSU's case).

+1

Other good brands: Delta, Lite-On, Astec

RetroLizard wrote on 2020-11-14, 00:58:

Are there any ATX power supplies that have all the same rails AT power supplies do?

Early ATX power supplies have all the same rails than AT (+5V, +12V, -5V, -12V) plus a 3.3V line. That's why there are such simple adapters (even though since the mid '00s the -5V line was removed from the ATX standard).

Alright. And for early ATX power supplies, which brands should I look for?

Just finished doing two cirrus logic video cards, both had 1MB with two empty sockets each and same type of VRAM so I transferred the two VRAM ICs from GD5436 to GD5430, soldered directly without sockets. Same with GD5436 but I supplied 4 pieces of 50ns for total 2MB, soldered and of course, no sockets used.

Used the circuit board heater and hot air station at work when I had spare time after finished my work queue spread out several days. Turned out beautiful, have to test both later.
My work is phone repair (microsoldering) and game console repair and anything in between if they happens to fall into my lap. On top of it, had experience as TV tech repair years prior and before that, repaired and
made electronics kits, disassembled old TVs and generally electronics including few dial phones at grandma's house since when I was a kid. I was lucky since Grandma hoarded stuff that people gave to her over the years.

Cheers,

My wife and I decided to do something completely nerdy and different this morning: a Monster Bash race!

We absolutely adore the Monster Bash DOS games, so we got up super early, made like a gallon of hot chocolate, and fired up two computers old enough to have floppy drives in them. Then we raced through all three episodes to see who could rescue those poor cats and dogs first.

What a fun morning! I won, but not by much. She was giving me the excuse that her 66MHz museum piece wasn't loading levels as quickly as my Windows 98 PC, with its speedy 80GB UDMA disk drive and 1.4GHz of back-to-the-future processing power.

Whatevs. Personally, I think it was just raw, standard def talent.

That sounds like one hell of a Saturday morning Steve. I'm glad I was able to get my wife into video games we've had some fun times.

Today I found time to test a 386 motherboard that I recently purchased, with a 386SX 25MHz CPU. Inserted a couple of 30-pin SIMMs and powered it up and happily it POSTs ok -

Motherboard seems to be from some kind of Ambra-branded LPX PC. I'd actually never heard of Ambra before.

So I spent a couple of hours testing a bag full of 30-pin SIMMs. A few 4MB modules it would not POST or recognise correctly, no idea if they're bad or this board just doesn't like them. All the 1MB modules worked fine and I did find a working combination of 4MB modules to max the RAM to 16MB!

Also connected up a 130MB IDE HDD I had and was able to boot into DOS & Windows for Workgroups 3.11.

Had some trouble getting into the BIOS at one point, it would just freeze, so I had to short the RTC reset jumpers. That worked and got me back into the BIOS again.

I'll probably just use this board for testing purposes, as I don't have any spare LPX form-factor cases to set it up permanently. This board is currently the fastest 386SX I have in my collection.

Wrote this to run the PC port of Garfield - Caught in the ACT in fullscreen on startup of Windows 3.11 inside DOSBox :

1#include <windows.h>
2
3int main(void) {
4	STARTUPINFO si;
5	PROCESS_INFORMATION pi;
6
7	ZeroMemory(&si, sizeof(si));
8	si.cb = sizeof(si);
9	ZeroMemory(&pi, sizeof(pi));
10	CreateProcessA("C:\\SEGA\\GARFIELD\\GARFIELD.EXE", 0, 0, 0, 0, 0, 0, "C:\\SEGA\\GARFIELD", &si, &pi);
11	Sleep(5000);
12	HWND handle;
13	handle = FindWindowA("Garfield", 0);
14	SetForegroundWindow(handle);
15	MoveWindow(handle, 0, 0, 640, 480, 1);
16	SetActiveWindow(handle);
17	PostMessageA(handle, WM_COMMAND, 301, 0);
18	CloseHandle(pi.hProcess);
19	CloseHandle(pi.hThread);
20	while (1)
21	{
22		if (FindWindowA("Garfield", 0))
23		{
24			Sleep(400);
25		}
26		else
27		{
28			ExitWindowsEx(0, 0);
29		}
30	}
31	return 0;
32}

Built with Microsoft Visual C++ 4.1, the last version to target for Win32S.

Then I mapped the keyboard keys to my Xbox 360 controller.

Now the game runs in fullscreen inside DOSBox right away, with its own version of WinG, and CD music without any problem.
I had to use those settings :

1cycles=max
2cputype=pentium_slow

And I don't have to play a platform game with a keyboard like some sort of caveman.

Good times !

PTherapist wrote on 2020-11-15, 19:03:

Today I found time to test a 386 motherboard that I recently purchased, with a 386SX 25MHz CPU. Inserted a couple of 30-pin SIM […]
Show full quote

Today I found time to test a 386 motherboard that I recently purchased, with a 386SX 25MHz CPU. Inserted a couple of 30-pin SIMMs and powered it up and happily it POSTs ok -

Motherboard seems to be from some kind of Ambra-branded LPX PC. I'd actually never heard of Ambra before.

So I spent a couple of hours testing a bag full of 30-pin SIMMs. A few 4MB modules it would not POST or recognise correctly, no idea if they're bad or this board just doesn't like them. All the 1MB modules worked fine and I did find a working combination of 4MB modules to max the RAM to 16MB!

Also connected up a 130MB IDE HDD I had and was able to boot into DOS & Windows for Workgroups 3.11.

Had some trouble getting into the BIOS at one point, it would just freeze, so I had to short the RTC reset jumpers. That worked and got me back into the BIOS again.

I'll probably just use this board for testing purposes, as I don't have any spare LPX form-factor cases to set it up permanently. This board is currently the fastest 386SX I have in my collection.

That is the same as my Ambra Sprinta board. I would advise you remove the battery. I didn't and now I have the joy of fixing all the vias and traces that got death by Varta. Word of warning, it does not like MS-DOS 6.22 (at least mine didn't when it was alive). Some odd incompatibility with the BIOS, if you try to warm boot it just beeps and locks up. And if its any help you can retro fit an reset switch using the header JP11 which is useful.

5 caps on my server were starting to look like this:

So I took the server apart and got the board out.

The best soldering you've ever seen, I even managed to singe the CPU bracket like a total expert:

The third and fifth one gave me some grief with reinsertion, I realize I need a better solder sucker, but they're in:

Now, the case I took the server out of I'm going to re-use for another build, so I had this modded (kinda hacked really) MDG case that I pulled a 1st gen i7 out of (subject of a future build - really nice components actually, for the period) - it is not attractive, it's got rust on it, and a giant hole in the top from where a fan was installed (the new power supply I used is beefier and the fan could not fit), and it has blue LEDs homebrew everywhere. I took . it all apart, soldered the wires to all the extra fans and LEDs, and tidied it up a little. I also brought the fan controller varistor up to the front and PL'd it to a very yellowed I/O cover (this server doesn't need optical drives). The advantage of this case is that it had 57 fans already in it and mostly wired correctly, so I just optimized them for airflow and put the rest together.

and then to address the hole at the top...

I found a license plate in a field marked for construction of a new small condo, so I picked it up out of the dirt (my son actually saw it first) and brought it home for a cleaning.

It's now PL'd and self-tapped to the top of the server

Overall a ratty case that has great ventilation built from scraps. No one will ever see this thing, it'll live in either the attic or the parts-closet (I'm thinking attic because it'll be cooler up there and LOTS of ventilation)

Here's what's inside:

It's some kind of Sempron with 2.25 gb of RAM and 6TB of storage on a NAS4FREE setup with dual 100MBPS cards. Immediate plans are to install a new config on a USB drive and mirror the settings off the single IDE hard disk in there and have it boot from USB, thus saving power, and freeing the drive for other retro projects.

Beautiful case mods 🤣:

It does the job 😉

Please change backplate for metal, not plastic to support the back of the board where CPU socket is. AMD socket heatsinks exert lot of pressure.

Cheers,

I'm not taking it all apart again. It's been like that for close to two decades now. When I took off the CPU cooler to clean and re-paste, the cooler didn't put that much pressure on it - in fact, with a little force, you can slide the cooler around.

If it breaks, I have bins full of this era of boards - they're relatively worthless for anything else IMO.

I am currently trying to figure out my everything in windows 95 currently has a reverb effect when my AWE-64 Value is active. Other than that, I have a now semi-final Win95 machine.