Latest score: Compaq Portable 486c

[mikerofone]

Thanks for the pictures. They are very helpful. I have been struggling with my own 486c for a while. My problem is that I can not adjust the brightness of the screen at all. I had been concentrating on the little board with the speaker on it but I may have to actually venture out and open up the whole display panel. Did you replace any of the tiny SMD capacitors?

Glad to hear they helped! FWIW, the brightness control on my computer also barely does anything. Just enough such that I think it does have an effect.
I did not replace any caps on the second board in my pictures, only the ones described on the first one which included the four smaller 47uF (?) SMD caps.

I am seeing some of this as well which I had attributed to failing caps but given how minimal it is I was willing to ignore it. If I end up opening up the panel itself I may then have to replace those as well as I don't want to reopen this machine again (the plastic is already very brittle)

The plastic on my machine was suprisingly easy to work with, nothing snapped!

Interesting. I tried upgrading mine with a working AMD Power Stacker 486 to 133 MHz 5X86 (i.e. works in other motherboards) and the system refused to boot. I have an Intel 486DX4-100 OD chip in there and it has been quite happy with that. I am wondering if the BIOS in the 486c/66 is different then the one in the original model and allows for the AMD chips to work. Can you tell me what the ESU identifies your CPU as please? TIA!

I guess you mean the Compaq Setup utility? It showed a 486/33 but I guess that might be bogus. I also couldn't find the 486c/66 utility, only the non-/66 one on this website (link at the end of the post): https://www.retropaq.com/setting-up-the-compaq-portable-486/
The tool reported that the config settings were stored in "nonvolatile memory" by a newer version of the software, so maybe a newer utility can show more. Since my computer is reporting a configuration error when starting (seems an ISDN card has been removed), I'll need to give configuration a try, but I wonder whether I can ruin anything if I use the older tool.

Edit2: Here are some pictures of the CPU installed. Quite the stack of adapters was needed, apparently.

Do you have the /66 config disks? If so, mind sharing the disk images? That would be awesome!

Cheers
Nikolai

Edit: Just for reference, in case you or anyone looking doesn't have it yet: The service manual is quite helpful for disassembling the machine. Available at minuszerodegrees. The machine is much easier to work with than that NEC PowerMate Portable luggable I have worked on before. Compaq clearly intended for people to service this machine without drowning in screws.

 

[Shadow Lord]

Glad to hear they helped! FWIW, the brightness control on my computer also barely does anything. Just enough such that I think it does have an effect.
I did not replace any caps on the second board in my pictures, only the ones described on the first one which included the four smaller 47uF (?) SMD caps.

Interesting. I would think that turning it all the way down would lead to a black/dark screen. The board I am talking about is not in your pictures. It is the one with the two pots on it for volume and brightness control. I am surprised the ceramic SMD caps (little rectangular ones) needed repalcing. Or are you talking about the radial SMD caps?

I guess you mean the Compaq Setup utility? It showed a 486/33 but I guess that might be bogus. I also couldn't find the 486c/66 utility, only the non-/66 one on this website (link at the end of the post): https://www.retropaq.com/setting-up-the-compaq-portable-486/
The tool reported that the config settings were stored in "nonvolatile memory" by a newer version of the software, so maybe a newer utility can show more. Since my computer is reporting a configuration error when starting (seems an ISDN card has been removed), I'll need to give configuration a try, but I wonder whether I can ruin anything if I use the older tool.

This is an EISA based system that requires a EISA Configuration Utility (ECU or ESU for EISA Setup Utility) to configure. It was an in between step of PnP PCI and ISA akin to MCA. Computers and add in cards have CFG files that tell the BIOS what resources they need and what settings they have. It gets a bit more comlicated then that but that is the general idea. The last ECU from Compaq is version 2.58. You can still download it at HP. Note that it probably does not have the CFG files for the Portable in the disk set. At least not for the original. That is no big deal though because you can dl the CFG from mR_Slug's.

I may try the Power Stacker one more time although speed with the 100MHz part is pretty good. It counts through the 32MB memory check relatively quickly now compared to the "original" 66MHz (I believe old owner had upgraded the 33MHz to 66MHz back in the day).

 

[mikerofone]

Interesting. I would think that turning it all the way down would lead to a black/dark screen. The board I am talking about is not in your pictures. It is the one with the two pots on it for volume and brightness control. I am surprised the ceramic SMD caps (little rectangular ones) needed replalcing. Or are you talking about the radial SMD caps?.

Ohh sorry for the confusion. I only changed electrolytics, i.e. the radial / can-shaped caps. I didn't mess with any ceramics since as you said, I don't think they fail with age. I have not done anything to the brightness control board, didn't even inspect it or remove it from the case. Does it have electrolytic caps, and if so, have you tried changing them?
I'd love being able to dim / turn off the backlight on demand. If the control will only adjust the backlight brightness and not display contrast, you won't have to mess with opening the display module. The backlight is not electronically connected to the screen module, its just screwed on its back.

This is an EISA based system that requires a EISA Configuration Utility (ECU or ESU for EISA Setup Utility) to configure. It was an in between step of PnP PCI and ISA akin to MCA. Computers and add in cards have CFG files that tell the BIOS what resources they need and what settings they have. It gets a bit more comlicated then that but that is the general idea. The last ECU from Compaq is version 2.58. You can still download it at HP. Note that it probably does not have the CFG files for the Portable in the disk set. At least not for the original. That is no big deal though because you can dl the CFG from mR_Slug's.

Well that sent me down a rabbit hole! :D A couple things that are worth sharing:

1. The HP download explicitly mentions the Portable 486 in the readme, so I assume it will already work without adding configs manually. Yet to be tested.
2. mR_Slug's webpage is a treasure trove! Maybe I can find a .cfg for the ISA network adapter I'm installing in the system.
3. Especially the "sources" part of mR_Slug's webpage was interesting. It contained a compaq archive from which HPaq.zip was very interesting: It has an allfiles.txt that is a listing of all Softpaqs ever released, as far as I can tell.
4. Writing Softpaq disk images in Linux is not straight forward, but I figured it out after a bit of searching. Since I couldn't find any description of this issue online, here are my steps which worked on Linux Mint 20.1:

Softpaqs use QRST5 compression, supported by libdsk v1.5.15 (>.9 which as of writing was the most recent Ubuntu package): https://www.seasip.info/Unix/LibDsk
libdsk comes with tools for converting the images (see https://www.mankier.com/package/libdsk-tools for full list).

Build libdsk at >=v1.5.15 and install it:

$ ./configure
$ make
$ make install install-man

It installs in /usr/local/... so you might need to add /usr/local/lib to your ld resolution path:

$ echo "/usr/local/lib" | sudo tee /etc/ld.so.conf.d/usr_local_lib.conf
$ sudo ldconfig

To unpack a Softpaq, make sure DosBox is installed and run:

$ cd <dir containing softpaq .EXE>
$ dosbox .

In DosBox, run the .exe file. Crank up CPU cycles using CTRL+F12 repeatedly. It will extract the disk image files in QRST format to the local directory. They are named XXXXX._NN.

To convert these to regular sector image files that you can write with dd:

$ for image in *._?? ; do dskconv -otype raw "${image}" "${image}.img" ; done

Determine your floppy drive's device name. BE CAREFUL or you might wipe the wrong drive / your hard disk! For USB drives, insert a disk and run lsblk to find it.

Assuming that your floppy drive is /dev/floppy, write individual files via

$ dd if=XXXX._NN.img of=/dev/floppy bs=4096 status=progress

I may try the Power Stacker one more time although speed with the 100MHz part is pretty good. It counts through the 32MB memory check relatively quickly now compared to the "original" 66MHz (I believe old owner had upgraded the 33MHz to 66MHz back in the day).

I have to yet to verify that the machine runs at the expected speed. The memory check takes about 25 seconds for the 28 MB, which seems quite a lot (video). But I don't know how slow it would be with the original CPU, what do you think?

Also, does anyone have the drivers (if any needed) for the video adapter and possibly other things for Win3.11 or Win95? I found some drivers in the C:\WINDOWS\OPTIONS directory of the Win98 install that was on there, but I have yet to check what they are for.

Cheers
mikerofone

 

[mikerofone]

1. The HP download explicitly mentions the Portable 486 in the readme, so I assume it will already work without adding configs manually. Yet to be tested.

Turns out you were right: Upon load, the setup asked for !CPQ1409.CFG. Copying all the files in http://66.113.161.23/~mR_Slug/EISA/!CPQ1409.CFG/2000-05-31/ onto the second setup disk worked. I also found my ISA NE2000 network card at http://66.113.161.23/~mR_Slug/EISA/!ISA8712.CFG/1998-03-15.

However, the system keeps reporting "Configuration not set" on boot, and every time the auto configuration reports "changes made: Boot device -> Internal HD controller" or similar when it runs. However, saving doesn't change this. I see that the other changes for the network card stuck, and date and time are still kept by the Dallas module. So I think the battery and NVRAM are still working fine.

Any ideas how to debug? I'm considering clearing the entire config using the clear jumper, but I am a little worried that maybe I'll make things worse.

Cheers
mikerofone

 

[Shadow Lord]

Ohh sorry for the confusion. I only changed electrolytics, i.e. the radial / can-shaped caps. I didn't mess with any ceramics since as you said, I don't think they fail with age. I have not done anything to the brightness control board, didn't even inspect it or remove it from the case. Does it have electrolytic caps, and if so, have you tried changing them?
I'd love being able to dim / turn off the backlight on demand. If the control will only adjust the backlight brightness and not display contrast, you won't have to mess with opening the display module. The backlight is not electronically connected to the screen module, its just screwed on its back.

Ok. I was not looking forward to replacing the ceramic caps. :D As far as backlight you may want to check this thread here.

I have to yet to verify that the machine runs at the expected speed. The memory check takes about 25 seconds for the 28 MB, which seems quite a lot (video). But I don't know how slow it would be with the original CPU, what do you think?

Also, does anyone have the drivers (if any needed) for the video adapter and possibly other things for Win3.11 or Win95? I found some drivers in the C:\WINDOWS\OPTIONS directory of the Win98 install that was on there, but I have yet to check what they are for.

25 seconds sounds a bit slow but I have to check when I get my system put back together. As for the video I think it is just a standard Compaq VGA video controller or at best an Advanced VGA controller. I think it is listed in the Service Manual. Drivers can be found on line.

 

[Shadow Lord]

However, the system keeps reporting "Configuration not set" on boot, and every time the auto configuration reports "changes made: Boot device -> Internal HD controller" or similar when it runs. However, saving doesn't change this. I see that the other changes for the network card stuck, and date and time are still kept by the Dallas module. So I think the battery and NVRAM are still working fine.

Any ideas how to debug? I'm considering clearing the entire config using the clear jumper, but I am a little worried that maybe I'll make things worse.

Check out this thread especially the last post.

Do you have the original HDD in there? If you do can you take some pictures of it and how it is setup in the drive cage? TIA!

 

[mikerofone]

Ok. I was not looking forward to replacing the ceramic caps. :D As far as backlight you may want to check this thread here.

I've replaced the one electrolytic cap on there (100uF, 20V, low ESR if I saw that correctly) which didn't change much. I do see an effect of the dial, but it feels like it allows setting the brightness in a range from 90% to 100% at best. Maybe the range was never any better?

25 seconds sounds a bit slow but I have to check when I get my system put back together. As for the video I think it is just a standard Compaq VGA video controller or at best an Advanced VGA controller. I think it is listed in the Service Manual. Drivers can be found on line.

Thanks, that makes sense. My Windows 98 install is configured with a Compaq Advanced VGA controller and 256 color mode is working.

Check out this thread especially the last post.

Thanks for the pointer! I've wasted half my day trying different setup versions, but in the end nothing made a difference. I couldn't get rid of the error on boot, but all other settings are set reliably.
I've also tried an EISA reset via the dip switches on the mainboard, which solved nothing. But I now feel that the display dithers colors differently, the Win98 boot logo looks a little grainy. :/ There were some video output related settings in the .cfg files, but none of the setup versions offered these when run. It's also possible that I'm just seeing things, because I was now looking for them.

I wonder whether this is caused by the different CPU. The setup shows 486/33MHz whatever I do, but from what I read about the Am586 it has an internal 4x multiplier, so it makes sense that the mainboard is none the wiser.

Do you have the original HDD in there? If you do can you take some pictures of it and how it is setup in the drive cage? TIA!

Yes, I have the original disk, a 504MiB one. There's not much going on, but here is the wiring: https://photos.app.goo.gl/RVNkTY7HKohu5n8AA
The drive has some sort of bracket mounted to it, so it slots into the space very snugly. I now realize that you probabyl wanted pictures of that, not the wiring... I've already put it back together, but let me know and I can open it again.

For now, I'm happy with the state of the machine and will until the soundcard and ethernet cards / cables arrive, so I can set the system up from scratch with Win95 and some nice DOS games.

Cheers
Nikolai

 

[Shadow Lord]

I've replaced the one electrolytic cap on there (100uF, 20V, low ESR if I saw that correctly) which didn't change much. I do see an effect of the dial, but it feels like it allows setting the brightness in a range from 90% to 100% at best. Maybe the range was never any better?

Maybe. It would be nice if other owners would pitch in and tell us what they have on their system. Although a 10% reduction seems strange to me. Did you check any other components on the board?

Yes, I have the original disk, a 504MiB one. There's not much going on, but here is the wiring: https://photos.app.goo.gl/RVNkTY7HKohu5n8AA
The drive has some sort of bracket mounted to it, so it slots into the space very snugly. I now realize that you probabyl wanted pictures of that, not the wiring... I've already put it back together, but let me know and I can open it again.

Thanks for the pictures. Actually I was interested in both. Since the power supply output was non-standard I was wondering if Compaq had a mating connector. Looks like they McGyvered it like I did on my system! LOL. If you have it all packed up no worries but if you ever get pictures of the HDD and the mounting bracket I would love to see it. Also is that a fan on the bottom (round bladed black plastic in your pictures)?

Edit: looking more closely it looks like they had a mating connector and that it is a fan. Does it look original to the system or do you think it was anaddon by the old owner?

TIA!