• Please review our updated Terms and Rules here

Restoring Compaq Portable 386

uscleo

Member
Joined
Oct 30, 2018
Messages
28
Location
Hong Kong
Hello!

Just want to say that this forum has been a godsend on my journey restoring my Compaq Portable 386. You guys rock!

I'm about mid way through restoring a Compaq 386 (technically is a 286 Compaq Portable III, but with a 386 board I got off ebay). Got a bunch of different spare parts and over the past 2 weeks have been piecing it back together. This thing is really cool - the orange plasma gas screen is very Aliens and the form factor is something out of Back to the future. Absolutely loving the aesthetics of this computer!

Here's what I have done so far (skip to questions below)

- Replaced the 5.25" floppy that was working intermittently with a 3.5" floppy from a 90's Compaq Deskpro (these fit the slot perfectly)
- Removed the keyboard and waiting to replace the dry rot cable and splice in a replacement - using a giant old AT keyboard for now that plugs in the front.
- Replaced the 40 mb hard disk with an IDE to Compact Flash (CF Card) adapter with a 512 MB card
- Downloaded and imaged the Compaq Diagnostics disk - needed each time the computer boots if you don't replace the CMOS / BIOS battery (will do this later)
- Formatted the Compact Flash drive to be able to be read from the Compaq Portable (Lots of research lead to the use FDISK /MBR in dos which allowed the CF card to be seen and then FORMAT to be run)
- Downloaded and imaged a few Compaq Dos Floppies to install Compaq Dos which has special functions such as MODE to switch between graphics modes without changing jumpers.
- Installed a mouse and Windows.


A few questions:

- Does anybody know anybody who might have the ram expansion board and some ram for the Compaq Portable 386? Ebay doesn't have them :-( willing to make a fair offer here :)

- Or, alternately, is it possible to add the 16bit ram expansion board (and the 16 bit ram card that comes with it) to the 32 bit 386? The 286 memory board adapter looks like it's slightly different and does quite fit, but if I could make it fit, would it work? Can 16bit ram run on the 386?

- Can I use a Cyrix 486 DLC CPU upgrade chip here? I have one but the 386 Processor CPU IC seems to be wedged in there very tight and I'm not 100% sure if it's been soldered on (looks like its not, and looks like it sits on a socket, but its really, really stuck on there. Is it simply unplug the 386 and plug in the 486 DLC?

- I also have the ISA expansion slot, and I was wondering if anyone had any advice for which type / brand / model of RAM ISA upgrade cards would work best here? I think I have to stay 16bit according to this the expansion slots support 8/16 bit only despite it being a 386 machine

- Also looking for recommendations for a good output quality and all round compatible VGA ISA card (16 bit)

Let me know what you guys think! Pictures coming tonight when I'm off work :D
 
- Does anybody know anybody who might have the ram expansion board and some ram for the Compaq Portable 386? Ebay doesn't have them :-( willing to make a fair offer here :)

Probably the most likely source would be a dead Compaq Portable 386. Anyone with the expansion board and a live Portable isn't likely to want to give it up.

- Or, alternately, is it possible to add the 16bit ram expansion board (and the 16 bit ram card that comes with it) to the 32 bit 386? The 286 memory board adapter looks like it's slightly different and does quite fit, but if I could make it fit, would it work? Can 16bit ram run on the 386?

Not likely, Compaq would have had to specificaly designed the 386 to reuse the 286's expansion boards.

- Can I use a Cyrix 486 DLC CPU upgrade chip here? I have one but the 386 Processor CPU IC seems to be wedged in there very tight and I'm not 100% sure if it's been soldered on (looks like its not, and looks like it sits on a socket, but its really, really stuck on there. Is it simply unplug the 386 and plug in the 486 DLC?

Yep! I've got the clock doubled version in mine. No jumper changes needed if I remember correctly. Might have needed one for the added math-coprocessor. There's a utility that needs to run on startup to enable the internal cache.

- I also have the ISA expansion slot, and I was wondering if anyone had any advice for which type / brand / model of RAM ISA upgrade cards would work best here? I think I have to stay 16bit according to this the expansion slots support 8/16 bit only despite it being a 386 machine

That will be the easiest way to add memory, but it will be much, much slower than on-board ram. No 32-bit expansion slots on the 386 Portable unfortunately, except the proprietary ram boards.

- Also looking for recommendations for a good output quality and all round compatible VGA ISA card (16 bit)

They're all about the same to me. My preference back in the day was for the Cirrus cards. I wouldn't bother buying anything with less than a meg of ram.

Let me know what you guys think! Pictures coming tonight when I'm off work :D[/QUOTE]

It's a pretty neat machine. The main issue I have with it is the display is only CGA. Maybe doubled (640x400) CGA? That and the difficulty in adding ram.
 
My first big question is why would you want a VGA card? Sure you get VGA on an external monitor but then the big selling point of the computer (the large gas plasma screen) is bypassed. Why not just look for a Compaq Portable 486? Your upgrade paths are a lot more practical, if not more affordable.
 
Hello!

Just want to say that this forum has been a godsend on my journey restoring my Compaq Portable 386. You guys rock!

I'm about mid way through restoring a Compaq 386 (technically is a 286 Compaq Portable III, but with a 386 board I got off ebay). Got a bunch of different spare parts and over the past 2 weeks have been piecing it back together. This thing is really cool - the orange plasma gas screen is very Aliens and the form factor is something out of Back to the future. Absolutely loving the aesthetics of this computer!

Here's what I have done so far (skip to questions below)

- Replaced the 5.25" floppy that was working intermittently with a 3.5" floppy from a 90's Compaq Deskpro (these fit the slot perfectly)
- Removed the keyboard and waiting to replace the dry rot cable and splice in a replacement - using a giant old AT keyboard for now that plugs in the front.
- Replaced the 40 mb hard disk with an IDE to Compact Flash (CF Card) adapter with a 512 MB card
- Downloaded and imaged the Compaq Diagnostics disk - needed each time the computer boots if you don't replace the CMOS / BIOS battery (will do this later)
- Formatted the Compact Flash drive to be able to be read from the Compaq Portable (Lots of research lead to the use FDISK /MBR in dos which allowed the CF card to be seen and then FORMAT to be run)
- Downloaded and imaged a few Compaq Dos Floppies to install Compaq Dos which has special functions such as MODE to switch between graphics modes without changing jumpers.
- Installed a mouse and Windows.


A few questions:

- Does anybody know anybody who might have the ram expansion board and some ram for the Compaq Portable 386? Ebay doesn't have them :-( willing to make a fair offer here :)

- Or, alternately, is it possible to add the 16bit ram expansion board (and the 16 bit ram card that comes with it) to the 32 bit 386? The 286 memory board adapter looks like it's slightly different and does quite fit, but if I could make it fit, would it work? Can 16bit ram run on the 386?

- Can I use a Cyrix 486 DLC CPU upgrade chip here? I have one but the 386 Processor CPU IC seems to be wedged in there very tight and I'm not 100% sure if it's been soldered on (looks like its not, and looks like it sits on a socket, but its really, really stuck on there. Is it simply unplug the 386 and plug in the 486 DLC?

- I also have the ISA expansion slot, and I was wondering if anyone had any advice for which type / brand / model of RAM ISA upgrade cards would work best here? I think I have to stay 16bit according to this the expansion slots support 8/16 bit only despite it being a 386 machine

- Also looking for recommendations for a good output quality and all round compatible VGA ISA card (16 bit)

Let me know what you guys think! Pictures coming tonight when I'm off work :D

Side.jpg
Landmark.jpg
Windows.jpg
Commander Keen.jpg
Prince.jpg
IMG_3200.jpg
IMG_3227.jpg
 
Pictures!

Pictures!

Hello!

Just want to say that this forum has been a godsend on my journey restoring my Compaq Portable 386. You guys rock!

I'm about mid way through restoring a Compaq 386 (technically is a 286 Compaq Portable III, but with a 386 board I got off ebay). Got a bunch of different spare parts and over the past 2 weeks have been piecing it back together. This thing is really cool - the orange plasma gas screen is very Aliens and the form factor is something out of Back to the future. Absolutely loving the aesthetics of this computer!

Here's what I have done so far (skip to questions below)

- Replaced the 5.25" floppy that was working intermittently with a 3.5" floppy from a 90's Compaq Deskpro (these fit the slot perfectly)
- Removed the keyboard and waiting to replace the dry rot cable and splice in a replacement - using a giant old AT keyboard for now that plugs in the front.
- Replaced the 40 mb hard disk with an IDE to Compact Flash (CF Card) adapter with a 512 MB card
- Downloaded and imaged the Compaq Diagnostics disk - needed each time the computer boots if you don't replace the CMOS / BIOS battery (will do this later)
- Formatted the Compact Flash drive to be able to be read from the Compaq Portable (Lots of research lead to the use FDISK /MBR in dos which allowed the CF card to be seen and then FORMAT to be run)
- Downloaded and imaged a few Compaq Dos Floppies to install Compaq Dos which has special functions such as MODE to switch between graphics modes without changing jumpers.
- Installed a mouse and Windows.


A few questions:

- Does anybody know anybody who might have the ram expansion board and some ram for the Compaq Portable 386? Ebay doesn't have them :-( willing to make a fair offer here :)

- Or, alternately, is it possible to add the 16bit ram expansion board (and the 16 bit ram card that comes with it) to the 32 bit 386? The 286 memory board adapter looks like it's slightly different and does quite fit, but if I could make it fit, would it work? Can 16bit ram run on the 386?

- Can I use a Cyrix 486 DLC CPU upgrade chip here? I have one but the 386 Processor CPU IC seems to be wedged in there very tight and I'm not 100% sure if it's been soldered on (looks like its not, and looks like it sits on a socket, but its really, really stuck on there. Is it simply unplug the 386 and plug in the 486 DLC?

- I also have the ISA expansion slot, and I was wondering if anyone had any advice for which type / brand / model of RAM ISA upgrade cards would work best here? I think I have to stay 16bit according to this the expansion slots support 8/16 bit only despite it being a 386 machine

- Also looking for recommendations for a good output quality and all round compatible VGA ISA card (16 bit)

Let me know what you guys think! Pictures coming tonight when I'm off work :D

FINALLY have some time to take some pictures

Load Screen (booting from Floppy)
AxWs6WZh.jpg


Side view with floppy from Compaq deskpro, CF card floppy replacement (still need to tidy that up)
gqr6pRmh.jpg


Windoze 3.1
pTWnp5Dh.jpg


Commander KEEN!
dvXFGSJh.jpg


Prince of Persia
rpMrXaNh.jpg


Landmark Bench (running Cyrix 486 DLC with no cache enabled
qv0zkleh.jpg


Trying to enable cache, but looks like the portable 386 board is not fully compatable
VFupwJqh.jpg
 
Tseng ET4000 or Cirrus Logic CL54xx

Managed to get my hands on a Cirrus Logic MORSE KP800, for cheap - seems impossible to find a Cirus Logis CL54xx ISA only PCI, saving up for a Tseng ET4000 - this one seems very popular - which variant is best? w32i or AX? Do you think I need the 2MB ram (probably do since I'm trying to basically get the CPU upgraded to a 486)
 
- Does anybody know anybody who might have the ram expansion board and some ram for the Compaq Portable 386? Ebay doesn't have them :-( willing to make a fair offer here :)

Probably the most likely source would be a dead Compaq Portable 386. Anyone with the expansion board and a live Portable isn't likely to want to give it up.

ah ok - I'll take a look around the market place and post some ads

- Or, alternately, is it possible to add the 16bit ram expansion board (and the 16 bit ram card that comes with it) to the 32 bit 386? The 286 memory board adapter looks like it's slightly different and does quite fit, but if I could make it fit, would it work? Can 16bit ram run on the 386?

Not likely, Compaq would have had to specificaly designed the 386 to reuse the 286's expansion boards.

yeah and even if it did it would be at 16Bit speed.

- Can I use a Cyrix 486 DLC CPU upgrade chip here? I have one but the 386 Processor CPU IC seems to be wedged in there very tight and I'm not 100% sure if it's been soldered on (looks like its not, and looks like it sits on a socket, but its really, really stuck on there. Is it simply unplug the 386 and plug in the 486 DLC?

Yep! I've got the clock doubled version in mine. No jumper changes needed if I remember correctly. Might have needed one for the added math-coprocessor. There's a utility that needs to run on startup to enable the internal cache.

Ran into a problem here - the software reccomends me go buy a flush board - did some quick googling and it looks like if I dont have a flush board I have to do some serious hardware tinkering - or did I get something wrong ? I followed the instructions and upon reset the utility test fails.

Do I have to try find an upgrade with the cache controlled by the CPU (like this Cyrix 486DRx http://www.cpu-collection.de/?tn=0&l0=co&l1=Cyrix&l2=Cx486+DRx)

- I also have the ISA expansion slot, and I was wondering if anyone had any advice for which type / brand / model of RAM ISA upgrade cards would work best here? I think I have to stay 16bit according to this the expansion slots support 8/16 bit only despite it being a 386 machine

That will be the easiest way to add memory, but it will be much, much slower than on-board ram. No 32-bit expansion slots on the 386 Portable unfortunately, except the proprietary ram boards.

Picked up an ISA ram board off ebay - hopefully the 5.25 floppy driver works cause it looks like it wont be much use without it (Everex Ram 8000 ISA)

- Also looking for recommendations for a good output quality and all round compatible VGA ISA card (16 bit)

They're all about the same to me. My preference back in the day was for the Cirrus cards. I wouldn't bother buying anything with less than a meg of ram.

Noted on the Ram - Looks like the Tseng ET 4000 2mb version.

Let me know what you guys think! Pictures coming tonight when I'm off work :D

It's a pretty neat machine. The main issue I have with it is the display is only CGA. Maybe doubled (640x400) CGA? That and the difficulty in adding ram.

Yeah the CGA is a shame - I really wish there was a way to get around it, but there isn't - some games like lemmings are surprisingly good, but some (like WINCIV - Civ for windows 3.1) are playable but most things are illegible.
 
My first big question is why would you want a VGA card? Sure you get VGA on an external monitor but then the big selling point of the computer (the large gas plasma screen) is bypassed. Why not just look for a Compaq Portable 486? Your upgrade paths are a lot more practical, if not more affordable.

Don't get me wrong - the warm orange plasma screen is why I picked this machine to restore. It's pretty neat.:cool: But I guess its sort of why they developed the expansion box for the ISA cards in the first place - the computer is pretty neat on it's own, but it lacks things like a color monitor and sound card that desktops of the time had. Mostly, this project is just about restoring the hardware and seeing how far I can upgrade the CPU and software. The VGA card is for when I am playing games or using other software that cannot use CGA - or is illegible in CGA mode.

If you know someone who has a Compaq portable 486, let me know. I'm interested in adding one to my collection.:-D
 
How'd you get it using a cF card? I tried to fit my Portable 386 with both a cF card/adapter and DOM but it ultimately refused to speak reliably to anything but a mechanical HDD. Stock IDE controller.
 
How'd you get it using a cF card? I tried to fit my Portable 386 with both a cF card/adapter and DOM but it ultimately refused to speak reliably to anything but a mechanical HDD. Stock IDE controller.

It was surprisingly easy - you have to get a powered CF card to IDE adapter (the power plug is a 4 pin type that 3.5 floppies use), then connect the HDD IDE cable to a separate working computer that has a floppy. If you boot DOS off a floppy, you can run FDISK, and it should see the drive - create a dos partition. Then what I did was FDisk /MBR to create the right master boot record info, then do FORMAT /S then I think I also did SYS A: C:

When that's all done, you will need to boot the 386 with the Compaq boot disk (Find it here in the pull down menu - while you are here you can also get the original compaq DOS if you like, but it will run 6.22 just fine) I found that using a non HD floppy 3.5 inch (720k formatted) worked best, formatted from another computer

Inside the diagnostics, hit setup, then make sure you change the fixed drive type to something a little smaller than your CF card (at least this worked for me) - I had a 512 MB so I chose type 38 (I think that tells the BIOS / CMOS my drive is something like 318 MB) and its been working like a charm ever since. Only HDD error I get is if I run the compaq diagnostics and then it tells me the hard drive is not configured properly, but other than that it works fine (also can remove the CF and using a usb reader add files to it from my 2015 macbook air, and no problems afterwards)

Let me know if that works
 
Huh...on non-physical media mine just couldn't touch the partition table under any circumstances, even when properly formed ones had been provided by other machines.
 
Huh...on non-physical media mine just couldn't touch the partition table under any circumstances, even when properly formed ones had been provided by other machines.

I read somewhere that certain CF -> IDE adapters don't work as well as others, or maybe the CF card is too new, maybe try with an older CF card.
 
Is there a specific make / model of IDE CF card adapter you should use to replace the hard drive in a Portable 386? Or are they all basically the same design, just needs to be a powered one? There are tons of different ones for sale on eBay.

Will the Portable 386 be able to boot into the diagnostic program off of a HD 1.44MB 3.5 floppy? Or does it have to be a DD 720K floppy?
 
They are all basically the same design. I have a Startech variant, and I have tried it with WD SiliconDrive II 2GB CF cards. My 486 absolutely hates it, even after trying with two Multi I/O controller cards. I am waiting for a 512MB CF to arrive to test it with.
 
I went ahead and bought the Startech CF/IDE adapter off of eBay along with a 128MB CF card. Does anyone know for sure if the Portable 386 can only boot into the diagnostic program from a 720K floppy? Or can it boot into it from a 1.44MB one?
 
Is there a specific make / model of IDE CF card adapter you should use to replace the hard drive in a Portable 386? Or are they all basically the same design, just needs to be a powered one? There are tons of different ones for sale on eBay.

Will the Portable 386 be able to boot into the diagnostic program off of a HD 1.44MB 3.5 floppy? Or does it have to be a DD 720K floppy?

I have a Portable 386 with a 1.2Mb floppy drive. It boots just fine from a 360k boot disk.
 
Back
Top