amigopi wrote on 2023-08-23, 21:22:

Tried a CF-IDE adapter on the good old Aptiva 2168 (P75), couldn't get it to work reliably, nor could the system boot using it. Will probably try again with another adapter and/or card later.

I have had strange compatibility issues with some CF adapters. I always thought that the ones with the little transistor packages were better than just simple resistors, but these adapters ended up having problems.

See here for more information:

Why does this CompactFlash to IDE adapter behave differently?

amigopi wrote on 2023-08-23, 21:22:

Tried a CF-IDE adapter on the good old Aptiva 2168 (P75), couldn't get it to work reliably, nor could the system boot using it. Will probably try again with another adapter and/or card later.

I could never get a CF-IDE to work reliably in my PS/1 DX2-66 (basically the father of the Aptiva in all respects) either, I think that is a road better not taken..

I dunno, folks, it might be something else: to replace the CF card, I added another drive to the Aptiva, a 6.4 gig Fujitsu spinning disk from '99, and it's displaying the same symptoms... Namely, everything seems to work in DOS (FDISK, FORMAT, XCOPY, running Duke 3D...), but when I try to even open any of the drives on the second disk in Windows 3.1, it immediately reboots the whole system. And in a kind of a hard way, too, as the BIOS then does the whole memory check routine.

What a weird thing.

amigopi wrote on 2023-08-24, 08:39:

I dunno, folks, it might be something else: to replace the CF card, I added another drive to the Aptiva, a 6.4 gig Fujitsu spinning disk from '99, and it's displaying the same symptoms... Namely, everything seems to work in DOS (FDISK, FORMAT, XCOPY, running Duke 3D...), but when I try to even open any of the drives on the second disk in Windows 3.1, it immediately reboots the whole system. And in a kind of a hard way, too, as the BIOS then does the whole memory check routine.

What a weird thing.

Do you have an IDE CD-ROM on the same chain? Moving the CD-ROM to the IDE controller on the sound card helped tremendously with IDE flakiness on my PS/1. For SOME reason it was not behaving well with IDE CD-ROMs, being less tolerant of some than others but ultimately not being stable with any..

appiah4 wrote on 2023-08-24, 08:58:

Do you have an IDE CD-ROM on the same chain? Moving the CD-ROM to the IDE controller on the sound card helped tremendously with IDE flakiness on my PS/1. For SOME reason it was not behaving well with IDE CD-ROMs, being less tolerant of some than others but ultimately not being stable with any..

No, it's alone on the second channel, set to MASTER. Same as the CF-IDE was.

Not sure if that's "retro" enough to be mentioned here but managed to add a NMVe PCI option ROM to some older AM3 mainboard's BIOS (AMI).
That one was featuring just "slow" SATA-II ports for SSDs as the only bootable interfaces (besides some ancient less-modern IDE & floppy ports).
But with a simple and passive M.2 to PCIe adapter it is now possible to boot from modern NMVe M.2 SSDs on this non-UEFI board.

Speed-wise it's not that huge leap compared to SATA-II rates (mainly limited by the supported PCIe revision and link width) but still.
About 420 MByte/s seq. read and 320 MByte/s seq. write on a PCIe 2.0 x1 port are still better than what's possible with SATA-II.

This was some research project I was on for some time now.
I'm very impressed that it worked out at all.
Thinking about what boards to "fix" next...

After ~25 years, I'm getting back into 486s, it seems.

I got a good price on a 486 VLB board recently, and started testing it out. At first there were stability problems with the L2 cache, but apparently the chips just needed to be reseated. I think one of the jumpers on the board was also set wrong.
I haven't touched a 486 since the 90s. It's a nice change to get away from PCI slots, and I love how discrete all the parts are on a 486, it feels a lot more like a proper pre-95 DOS system.

I also have an ISA-only 486 board that doesn't work, but I'm feeling a renewed enthusiasm to try to fix it.

The 486 boards (especially the ISA-only board) are small enough to fit comfortably in a small Baby AT case that's been sitting around, and which has a MHz display on it. I don't know anything else I'd want to put in that case, so basically there's no reason not to build a 486.

I was anticipating a DOS build with an Intel socket-4 Pentium board - but it's a big board. I'm realizing the 486 makes more sense because of that small case. So the 1993 Pentium is starting to look redundant. Maybe I'll do both, but I'm coming to grips with the idea that the Pentium isn't going to last and the 486 will probably be the one to keep. It's definitely looking more interesting to me right now.

amigopi wrote on 2023-08-24, 09:04:

appiah4 wrote on 2023-08-24, 08:58:

Do you have an IDE CD-ROM on the same chain? Moving the CD-ROM to the IDE controller on the sound card helped tremendously with IDE flakiness on my PS/1. For SOME reason it was not behaving well with IDE CD-ROMs, being less tolerant of some than others but ultimately not being stable with any..

No, it's alone on the second channel, set to MASTER. Same as the CF-IDE was.

Only thing I can see is to put a new SS14 (I don't think it is that) and solder the power plug (two pins look week on solder).
Probably a more sophisticated design could help, with more components...
Many times people complain but the adapters are the bare minimum.

Checked voltage rails? is +5V good, 3.3?

Today my english is bad but you get the idea I hope 😀

Nexxen wrote on 2023-08-24, 11:01:

Today my english is bad but you get the idea I hope 😀

Your English looks OK to me. There are many native English speakers who can't write as well as you do.

I've been reverse engineering (with IDA 3.7 in MS-DOS) Legends of Valour, one of my favorite CRPG games of all times.

Nexxen wrote on 2023-08-24, 11:01:

Only thing I can see is to put a new SS14 (I don't think it is that) and solder the power plug (two pins look week on solder). P […]
Show full quote

amigopi wrote on 2023-08-24, 09:04:

appiah4 wrote on 2023-08-24, 08:58:

Do you have an IDE CD-ROM on the same chain? Moving the CD-ROM to the IDE controller on the sound card helped tremendously with IDE flakiness on my PS/1. For SOME reason it was not behaving well with IDE CD-ROMs, being less tolerant of some than others but ultimately not being stable with any..

No, it's alone on the second channel, set to MASTER. Same as the CF-IDE was.

Only thing I can see is to put a new SS14 (I don't think it is that) and solder the power plug (two pins look week on solder).
Probably a more sophisticated design could help, with more components...
Many times people complain but the adapters are the bare minimum.

Checked voltage rails? is +5V good, 3.3?

Today my english is bad but you get the idea I hope 😀

As the same problems happen with an actual hard disk at well, I don't think the CF-IDE adapter is (solely) to blame. And I can't solder anyway. (Boo! Hiss!)

I'll test with a different IDE cable later and maybe start a new thread if the problems persist. It's not critical, just inconvenient.

amigopi wrote on 2023-08-24, 11:59:

Nexxen wrote on 2023-08-24, 11:01:

Only thing I can see is to put a new SS14 (I don't think it is that) and solder the power plug (two pins look week on solder). P […]
Show full quote

amigopi wrote on 2023-08-24, 09:04:

No, it's alone on the second channel, set to MASTER. Same as the CF-IDE was.

Only thing I can see is to put a new SS14 (I don't think it is that) and solder the power plug (two pins look week on solder).
Probably a more sophisticated design could help, with more components...
Many times people complain but the adapters are the bare minimum.

Checked voltage rails? is +5V good, 3.3?

Today my english is bad but you get the idea I hope 😀

As the same problems happen with an actual hard disk at well, I don't think the CF-IDE adapter is (solely) to blame. And I can't solder anyway. (Boo! Hiss!)

I'll test with a different IDE cable later and maybe start a new thread if the problems persist. It's not critical, just inconvenient.

🤣 - we do what we can, if it works it's success!
Otherwise it's an excuse to go buy a new system to both console and make us post here with confidence 😀

With the lazy temp of 35°C I'm absolutely not doing any soldering. I'm doing all the "cold" work I can on my machines.

oh2ftu wrote on 2023-08-23, 18:07:

I transferred a Kaimei MB with a p166MMX to a cleaner case. Man, those baby-AT cases can be tight :-) Hitachi 4x CD-rom, Teac 5. […]
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I transferred a Kaimei MB with a p166MMX to a cleaner case. Man, those baby-AT cases can be tight 😀
Hitachi 4x CD-rom, Teac 5.25" floppy and a Mitsumi 3,5" floppy. All should work... I've heard that before though.
I will have to pull some RAM to get a "smart amount". Now it's at 96MB, consisting of 4xSIMM + 2xDIMM. I guess 64MB would be more than enough for this.
DOS6,22 + Windows 95 is what I had in mind. No clue about the sound card yet. I've got some Sound blasters.
For GPU I think it'll be an S3 or similar with a Voodoo1.

Hooh. What a PITA to pull that MB out for pics 😀
Had a VERY odd RAM config, 4x32MB simm + 2x16MB dimm which showed as 96MB. Go figure.
CT3600 as sound card, 6,4GB Quantum fireball (yes yes it's a bit large) and a 3com PCI 😀
VGA-card became a Matrox Mystique. Voodoo1 to be added when I get my passthrough cables and test them. OS installation pending...

shamino wrote on 2023-08-24, 11:01:

I got a good price on a 486 VLB board recently, and started testing it out. At first there were stability problems with the L2 cache, but apparently the chips just needed to be reseated. I think one of the jumpers on the board was also set wrong.
I haven't touched a 486 since the 90s. It's a nice change to get away from PCI slots, and I love how discrete all the parts are on a 486, it feels a lot more like a proper pre-95 DOS system.

Agreed, there is something enjoyable about working on older AT-era hardware with discrete controllers and other hardware.

Plus the ISA-era of sound cards is imho the most interesting era for computer audio. Lots of fun to be had there as well.

Nexxen wrote on 2023-08-24, 13:03:

With the lazy temp of 35°C I'm absolutely not doing any soldering. I'm doing all the "cold" work I can on my machines.

The 35 degrees might otoh give you ac boost for the soldering temperature 🤣

PD2JK wrote on 2023-08-22, 14:33:

Back to the drawing board... To be certain the memory chips are good, I got a fresh G400 on the way which I will be testing first.

DSC_5797~2.JPG

I wish you luck with this, I don't have the guts yet to try this on my only working MS6168 board yet.
Have you seen this video though? You need to change a resistor position for the higher density RAM to essentially access its upper half using one of the address lines as a chip select line: https://www.youtube.com/watch?v=wC40KY_e6K8

btw are you soldering the QFP memory chips down with hot air? Given the exposed pins I'd just hand solder them instead with a good amount of flux.

I found this mini hot plate thing on ebay (a cheapified clone of the miniware hotplate) for £20 and am gonna give it a go, it's a bit small for a motherboard though 😀 But it might work for fixing some video cards

H3nrik V! wrote on 2023-08-24, 15:30:

Nexxen wrote on 2023-08-24, 13:03:

With the lazy temp of 35°C I'm absolutely not doing any soldering. I'm doing all the "cold" work I can on my machines.

The 35 degrees might otoh give you ac boost for the soldering temperature 🤣

It's 35, not 350... 😀

Btw, it's easy to speak when you have a max of 22°C........ Only writing it made me feel a tab bit cooler 🤣

Anecdote: I was doing some sorting in my work folder. It was hot and, as I was listening to some YT history stuff, it went on playing "avoid frostbite winter camping".
Humour is the universal spice of life.

Removed some stubborn heatsinks.

Thermalwrong wrote on 2023-08-22, 15:38:

Good thing I did this too, I found a load of corrosion on the Trident 8900CL-B card's RAMDAC that caused the display to go all crazy. It turns out this is also a fast ISA card once the 0-wait states setting is enabled, pretty good for a VGA card that can do 8-bit too.
IMG_1750 (Custom).JPG

Had been a while since I last put my 486 through its paces. I always prioritise running games at full window before anything, and the Trident Quadtel TVGA8900CL 1MB surprised me, didn't remember Doom ran so well with it and a DX2-66. A little less performance at high detail but comparing to low detail it's honestly not that much of an improvement for me, and the fluidity and extra fps at low detail tips it for me. Duke 3D doesn't perform that great at high detail, and low detail's quality is unacceptable for me, so it's a no go on this PC.

But what I didn't expect was Terminal Velocity to run like it did on this PC. I mean, how can this perform at a very acceptable level, and Duke 3D does not?...

I needed an EPROM eraser to reprogram some old BIOS chips.

The cheap EPROM erasers on Amazon don't have a good reputation for quality, so instead I bought a UV sterilizer designed for disinfecting baby pacifiers.

It has four UV-C LEDs inside. I just taped down the EPROM on top of one of the LEDs.

It does have an annoying 1 minute timer. Fully erasing an EPROM took about 15 minutes, so that meant restarting it 15 times. But it did ultimately work.