Compaq LTE Elite 4/50E

Project Compaq LTE 4/50E
I found a 1994 laptop, what can it still do?
Status	In progress
Contact	Peetz0r
Last Update	2018-03-25

I found this old laptop and I'm figuring out what to do with it. Fun fact: this laptop is almost exactly as old I am.

First impression

Status when I found it

It had the (presumably) original harddrive still present and working (after 23 years!). On it was Windows 3.x with lots of Compaq bloatware and personal data of the previous owner. I decided top keep this as-is, because the original software/drivers/etc is hard to find/replace but I did not peek around very much because of privacy reasons. The battery was very much dead, the floppy drive did not work, and the bottom RAM cover was missing, but it did work just fine. A service manual was easy to find online: Media:Compaq LTE Elite service manual.pdf (2.6 MB, 387 pages).

Specs

• 486 DX2 50 MHz
• 8 MB ram (4MB onboard + 4MB on a proprietary expansion card)
• 250 MB harddisk
• 9,5" 640x480 monochrome TFT display
• 2-button PS/2 trackball
• PC speaker
• 2 empty PCMCIA slots
• 3,5" floppy drive (broken)
• 12V 2Ah NiMH battery (dead)
• no real soundcard
• no network hardware of any kind

Storage

The first thing I did was take out the original harddrive and go replace it with something else. I went to Aliexpress and got myself a IDE-CF adapter and a 2GB CF card. It could not boot from the card. I borrowed some more cards from another Revspacer and found out that cards up to 1Gb work but larger cards do not. But since the original disk was 250 MB, I decided that 256MB would be enough. I ordered a "industrial" 256MB card and it has been working just fine so far. The original harddrive sits in a aluminium caddy, which is easily removable. That's great, since this is the only way to move files from/to this machine I'll have to use this rather often.

Floppy drive

The floppy drive does not work. It does make some noises but the disk never spins. The rubber belt inside was very much disintegrating, but replacing the belt did not result in a working drive yet. But even if it did, I have no other devices anywhere with a floppy drive anyway. WONTFIX. By the way, the drive is a Citizen W1D.

Display

The monochrome screen is surprisingly good. The contrast is great, the resolution is... Very Good Anyway. The lack of subpixels makes it look very sharp. And there is no ghosting at all. I have seen early 90's laptops before where you could draw shapes by moving the mouse. Not this one. There is only one thing missing: color. But it's okay, there is a VGA port on the back, and there is plenty of color in there.

Sound

There is only a PC speaker inside. But it's a very loud one. Fortunately we get to change the volume trough Fn keys. It even has a graphical overlay on top of textmode MS-DOS, without any drivers!

But I want more! I did but two parallel port soundcards: a OPL2LPT (AdLib clone) and a CVX4 (Covox Speech Thing clone). Here is a YouTube video demonstrating how that looks. Fun fact, that laptop in that video is the high-end model of the same series as this one!

The OPL2LPT works perfectly fine, but I haven't had much luck with the CVX4 yet. Needs more testing...

Modding!

BadgeBay™

Since the battery is completely dead, I removed it. We now have space to fit stuff in. This space is just wide enough to fit a SHA2017 Badge inside. No joke, it fits like a glove! Well, after some creative OpenSCAD and 3d-printing work that is. I printed many failed attempts in red PETG and just as it was about to run out I did my final print. So I inserted the green PETG in the bowden extruder while the red filament was still in the tube. They print at the same settings anyway, but the layer effect turned out very nice, by accident.

Serial port

I also ordered a bunch of MAX232 boards and I had some CH340 ttl-serial-usb lying around. So I took one of both and connected them to my modern linux laptop at first. I could get a serial console, run ssh, and even revbank inside the Windows 3.1 Terminal app.

So I now needed a way to connect the Badge sitting in the battery bay to the serial port on the back of the laptop. Complete disassembly was required. I decided to make a second serial port parallel to the first port. This breaks when you connect devices to both ports, so don't do that then!. At first I connected it directly to a MAX232 board, but than I decided to make it removable, just like the original battery. So I yanked a DE9 port from an old desktop board from the e-waste pile and soldered it in parallel to the rear port on a short ribbon cable, snipped away some plastic, added some padding and hotglue. We now have a internal DE9 serial port inside the battery bay BadgeBay™!

During the disassembly process the fan connector broke off. But that's okay as you'll read in the next section.

+5V hackery

Up to this part, the Badge and the CH340 and MAX232 were powered from an external USB supply (mostly my modern laptop since I was flashing/debugging the Badge all the time anyway). But this wouldn't be good enough for a permanent setup. So I needed a way to connect Ground and +5V from the laptop to the badge. Ground was already present in the DE9 connector, so we are already halfway! But that's not enough. I needed a way to connect one extra pin reliably while keeping the carefully constructed hotpluggable toolless BadgeBay™ system intact. So i snipped one of the retaining screw thingies seperate from the shielding, connected a red wire, and then I hotglued a metal spring to the inside of the laptop. I soldered a red wire to the spring as well. I lined the spring up with the DE9 retaining screw.

Back to the broken fan connector. I spliced the wires from there and from the spring (and later another wire for the OPL2LPT) together and connected those to the pads behind the fan connector. We now have a BadgeBay™ +5V rail!

At this point the BadgeBay™ hardware was more or less working. A few weeks later I ordered my soundcards. The CVX4 does not need any external power, but the OPL2LPT does. It has a mini-usb connector to power it from a nearby USB port, which this laptop lacks. Powering it from any external source works fine but is clunky. The OPL2LPT kit already has pads for a DIY power header. Since the ground was already connected trough the pins in the port and/or shielding, I again only needed to worry about the +5V. So I added another red wire to my already existing splice near the fan connector and made this one long enough to reach all the way from there to the left side of the laptop, trough the PCMCIA cover, around the back, and into the OPL2LPT +5V header. But when nut in use, this cable hides neatly begine the PCMCIA door.

(more text and pics coming soon!)

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  Serial - MAX232 board - CH340 board - USB

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  Revbank over serial console