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Upgrading/Modifying the Compaq Portable 386 for the Retrochallenge 2013WW

arrow_runner

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Joined
Mar 7, 2012
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Cincinnati Ohio
For those that don't know about the challenge, see here for details. It's only until the end of the month but there's still time to join if you want.

You have to have a 'blog' to enter so that's what this thread is going to be.

I'm going to get as much as I can done, but I don't have any expectations to get every single thing done by the end of the month. This project is really more about the journey than the destination anyway. There's going to be a bit of electrical engineering study/research involved with a few of these steps. I've always wanted to get into EE more but I never really got around to it so that's what the latter portion of this is really about.

To do list:
  • Replace CMOS battery
  • Replace IDE hard drive with CF Card
  • Upgrade CPU to a 486
  • Overclock the 486/387
  • Add a sound card that will support a CD-ROM
  • Add a 3.5" Floppy drive
  • Add (laptop) CD-Drive
  • Add network card
  • Add wireless G wifi access
  • Increase ram from the stock 2mb. (This is a trick because everything is proprietary and hard to find)
  • Enable > ~520mb hard drive drive (1-4GB Compact Flash)
  • Replace the power supply with Li-ion or lead acid batteries and make a charging circuit so the system uses a standard laptop charger.
  • Convert the keyboard to wireless
  • Add a wireless mouse (I still need to check if there is a second serial port this can go to)
  • See if the expansion bay can be modified to allow for a third ISA card (VGA Card)

So far I've done the following.
  • Replaced the old CMOS battery with a coin-cell (I was SOO tired of resetting the hard drive config...)
  • Install 4GB CF Card (formatted to about 400mb)
  • Upgraded CPU to a CX486DLC
  • Removed the stock 40MHz Crystal and installed a socket to try different crystals for overclocking. I have a 48MHz and 50MHz currently and have confirmed that the 48MHz did speed up the 386DX that was in the computer. No benchmarks yet.
  • Installed a Sound Blaster, haven't tested it's CD-ROM connection yet but I have about 2 different ones if this doesn't work
  • Installed a 3com network card and dos TCP/IP stack
  • Tried 3 different untested 3.5" floppy drives and all 3 give the same errors...
  • Added 2 standard molex and 1 floppy power connection inside the expansion bay
  • Modified a Linksys router for installation in the expansion bay - The 386 can ping it but the telnet program on it won't connect for some reason. I haven't tried another one yet. The router has Lynx installed on it so I'll have WWW access once I can Telnet to the router succesfully.
  • I've traced about 90% of the ram expansion module port to the motherboard (to see about making a ram expansion card myself since they're pretty rare)

I also plan on painting the whole shebang at some point. I'm thinking black with yellow trim.

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Oh the mess....
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Replacing the power supply might be tricky. There are some non-standard voltages on some of the wires going to the display - at least one of them over 100V iirc.
 
Replacing the power supply might be tricky. There are some non-standard voltages on some of the wires going to the display - at least one of them over 100V iirc.

Gotcha. I haven't checked it yet but I'd assume that it would use a circuit similar in theory to laptop LCD inverters? Did you find some documentation on that? I'm curious as to how you found that out.
 
My old Portable had some problems with the display and I measured all the voltages when trying to troubleshoot it. There were definitely higher voltages that 12V, but I couldn't say exactly what they were used for.
 
My old Portable had some problems with the display and I measured all the voltages when trying to troubleshoot it. There were definitely higher voltages that 12V, but I couldn't say exactly what they were used for.

I have a spare 386 power supply sitting at my shop. I didn't think to test the voltages going to the LCD. Were they DC or AC? And from the looks of it the PSU casing is using for the ground?

I think you'll find that you need a lot more current than a backlight inverter can supply.

Well I honestly don't know what the plasma LCD needs just yet. I was just saying that because if it's lit with a CCFL like a laptop then it at least the CCFL part would probably take a small backlight inverter or something similar.
 
Updates:
  • Replaced the Sound Blaster I was using with a Vibra 16 (better CD-ROM support)
  • Set up the CD/DVD-ROM. Turns out newer DVD-RW drives won't work with the Vibra
  • Installed SSH2DOS which allowed me to finally Telnet into the router
  • And not directly related to the project but I FINALLY got a file transfer program to work with my null modem cable. I still don't know why LapLink 3 and 5 never worked properly.....

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A very short "It works!" Video
 
I have a spare 386 power supply sitting at my shop. I didn't think to test the voltages going to the LCD. Were they DC or AC? And from the looks of it the PSU casing is using for the ground?

DC, can't remember if it was positive or negative with respect to ground.

Mike is probably right about it needing more current too. Plasma displays give out their own light, so they don't have a separate backlight in the way LCDs do. You'd have to power the entire display to get any output. The power supply is 145W which is typical for a full sized computer of the time, so there's quite a bit of current on the various voltage lines.
 
Gotcha. Well I have good news and bad news.

The good news is that I found my kill-a-watt and turning the computer on with the LCD power disconnected dropped the watts by about 5-7. The highest I could get the wattage to go was just shy of 90 with the sound, cd, router going, and windows 3.1 loading. The floppy drive would have added a little to that had I thought about it.

The bad news is that either my extra PSU was damaged during shipping along with the LCD because of a careless seller, or I damaged it somehow. I got it to stay on to see the voltage spike to just about 200 VDC, but the voltage was fluctuating bad and the PSU died shortly thereafter. :/

The possibly other good news is that I found another 386 that I was going to pick up for parts anyway but I'm still working with the seller on price.
 
Was the power supply connected to anything at the time? It's a switch-mode supply, so it needs a certain minimum load before you get sensible outputs. If it was completely disconnected then the voltages will be unstable and it might turn itself off eventually.
 
It's definitely possible but it went south real quick. I know your supposed to put a little load on power supplies but I've done it (no load other than PSU fan) before and never ran into one going out, let alone so fast. I'll be more careful next time just in case. I've been meaning to order some components to make an ATX PSU into a benchtop power supply so I'll order a couple extra of the big resistors for 'load simulation'.

http://www.youtube.com/watch?v=z2oSFpKh_Uw is what I was going to follow. I also like that his English reminds me of Borat.
 
I keep forgetting that these old manuals actually have useful information in them....

Table 2-14. Power Supply Specifications
==============================================================================
Input Requirements:
Line Voltage 120/230
Line Fuse 3A at 120, 2A at 230
Line Frequency 47/62 Hz
------------------------------------------------------------------------------
Power:
Steady State 165 watts
Peak State 180 watts
------------------------------------------------------------------------------
Cooling Forced air via 12 VDC fan
------------------------------------------------------------------------------
VDC Output:
Nominal
Continuous Maximum
Nominal Current Current Peak Regulation
Voltage Minimum Maximum Current Tolerance
------------------------------------------------------------------------------
+5.0 VDC 3.0A 14.3A 3%
+12.0 VDC 1.0A 3.0A 5.0A 5%
-12.0 VDC 0.0 0.56A 1.0A 5%
+200.0 VDCI 0.0 0.16A ñ 5 VDC
5.0 VDCI 0.0 0.06A 5%
------------------------------------------------------------------------------
NOTE: These values are maximum values based on nominal operating conditions
for temperature, line voltage, frequency, and altitude. Also, a minimum load
of +12 VDC must be maintained for proper power supply operation.
==============================================================================
 
So I've decided to not even try to convert the machine over to battery power before the end of the month. The wireless keyboard/mouse and expansion bay checking will also be put on hold. I still plan on attempting these things it's just that I have quite a bit to learn still and don't want to damage anything. In fact I'm probably going to be ordering my first oscilloscope soon and am really considering getting http://www.saelig.com/product/PSPC017.htm If anyone has opinions about that scope I'm all ears.

Update
  • 3.5" Floppy is working now
  • I actually have a lead on the additional 8mb ram so I'm waiting on that and should know by Monday if I'll be getting it
  • The eprom burner I wanted to buy ran out of stock so I'm still waiting to try the XT-IDE BIOS out in the NIC
  • I ran one benchmarking utility to verify the overclocking (Up to 50Mhz for the 486, 25Mhz for the 387) but would like to run a couple more tests
  • I finally got the handle off of the spare casing and know how I'll be painting everything and plan on doing that his weekend.
 
Well I didn't get to take it out tonight because of a two reasons...

1st off I had some issues telnetting into the router that wasted a good bit of my time but I figured out and should probably take notes next time I set something like this up.

The 2nd reason is because of Murphy's Law. The hard drive that had Windows 98 on it in my tweener decided that today would be a fantastic day to do it's best Super Kami Guru impression http://www.youtube.com/watch?v=SYN_VNYKz7g&feature=player_detailpage#t=619s (mild language)

That was pretty much the only efficient way of transferring files to the Compaq I had setup so that halted a bit of my progress. I wanted to put a few more games on as well as couple more utilities. Oh well I'll fix that later.

I have ordered an EPROM burner but it won't be here for another week or two at least. I've held off on ordering a oscilloscope because I've learned that it's important that they be plugged in to a grounded outlet and I need to check if there are any available in a convenient location in my house because I remember that being an issue on the house inspection when I moved in.

I did do a couple test paints and decided that flat black with trim black would look really Darth Vaderish. Unfortunately between me being sick all last week and the weather being as screwy as possible this week I didn't get anything else done with the paint.

As I mentioned the ram finally came in. It's installed for the time being but I do still plan on seeing what it would take to make aftermarket replica boards for other Portable 386 owners. (And technically I have 2 working systems now so it would be nice to max out both)

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I slid some heat shrink tubing over the spare handle from my busted 'parts' system. It turned out really nice. The red was okay but I really didn't like how shiny the matte was on the LCD bezel.

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This is what I saw when the donor system came in today...luckily it was wrapped in a couple layers of bubble wrap.

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The donor system's hard drive started smoking when I took it out and hooked it up. I pulled the cap off and it spun up just fine. I'm curious as to what would be on the hard drive to require 10mb of ram. The system also had a huge full length 8-bit ISA modem in the expansion bay.

20130131_115513_zps5d5aa550.jpg


My stupid tweener box. I FINALLY get it to stop locking up by narrowing the problem down to a bad SATA card and then the IDE hard drive decides to quit on me...

20130131_221414_zps600b2673.jpg


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I actually like the aesthetic of the way the add-ons and wiring are just stuck on the system. I can't think of the right words to describe it but it's kind of like when Johnny 5 bolted all that stuff on to himself in the 2nd movie or like how Doc Brown modded the Delorean.



And lastly, the first two levels of Silpheed: http://www.youtube.com/watch?v=23uD0qQ_HMU
 
Well I didn't get to take it out tonight because of a two reasons...

1st off I had some issues telnetting into the router that wasted a good bit of my time but I figured out and should probably take notes next time I set something like this up.

The 2nd reason is because of Murphy's Law. The hard drive that had Windows 98 on it in my tweener decided that today would be a fantastic day to do it's best Super Kami Guru impression http://www.youtube.com/watch?v=SYN_VNYKz7g&feature=player_detailpage#t=619s (mild language)

That was pretty much the only efficient way of transferring files to the Compaq I had setup so that halted a bit of my progress. I wanted to put a few more games on as well as couple more utilities. Oh well I'll fix that later.

I have ordered an EPROM burner but it won't be here for another week or two at least. I've held off on ordering a oscilloscope because I've learned that it's important that they be plugged in to a grounded outlet and I need to check if there are any available in a convenient location in my house because I remember that being an issue on the house inspection when I moved in.

I did do a couple test paints and decided that flat black with trim black would look really Darth Vaderish. Unfortunately between me being sick all last week and the weather being as screwy as possible this week I didn't get anything else done with the paint.

As I mentioned the ram finally came in. It's installed for the time being but I do still plan on seeing what it would take to make aftermarket replica boards for other Portable 386 owners. (And technically I have 2 working systems now so it would be nice to max out both)

20130131_221123_zps63ead8ce.jpg


20130131_221024_zps6b47269e.jpg


20130131_220956_zps55fc830b.jpg


I slid some heat shrink tubing over the spare handle from my busted 'parts' system. It turned out really nice. The red was okay but I really didn't like how shiny the matte was on the LCD bezel.

20130131_220914_zps9c4d1499.jpg


This is what I saw when the donor system came in today...luckily it was wrapped in a couple layers of bubble wrap.

20130131_105227_zpsab39b3f1.jpg


The donor system's hard drive started smoking when I took it out and hooked it up. I pulled the cap off and it spun up just fine. I'm curious as to what would be on the hard drive to require 10mb of ram. The system also had a huge full length 8-bit ISA modem in the expansion bay.

20130131_115513_zps5d5aa550.jpg


My stupid tweener box. I FINALLY get it to stop locking up by narrowing the problem down to a bad SATA card and then the IDE hard drive decides to quit on me...

20130131_221414_zps600b2673.jpg


20130131_221439_zpsdc3e4dc2.jpg



I actually like the aesthetic of the way the add-ons and wiring are just stuck on the system. I can't think of the right words to describe it but it's kind of like when Johnny 5 bolted all that stuff on to himself in the 2nd movie or like how Doc Brown modded the Delorean.



And lastly, the first two levels of Silpheed: http://www.youtube.com/watch?v=23uD0qQ_HMU

Hi There,

This post is a bit old, now but it was an inspiration - I'm in the middle of restoring and upgrading a compaq portable 386 myself: http://www.vcfed.org/forum/showthread.php?66562-Restoring-Compaq-Portable-386

Did you ever end up making any 386 modem/memory interface boards?
 
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