Ericsson Portable PC type 8400-005

[Ruud]

I now own such a PC and would like to obtain some technical information about it like the schematics and the pin-outs of its expansion connector. But nothing to be found, not even a user's manual

So any link is welcome, TIA!

 

[MattisLind]

Happen to search for Ericsson PC and found this post. The EPPC is a manufactured by Panasonic for Ericsson. I have some manuals for it but not the schematic. These machines are notorious for getting bad screens.

 

[Ruud]

Happen to search for Ericsson PC and found this post. The EPPC is a manufactured by Panasonic for Ericsson. I have some manuals for it but not the schematic. These machines are notorious for getting bad screens.

Oops, I just send an email using the "Contact" of your museum. Wanting to thank you I just realized that you are the Mattis that I sent the mail.

Of course I want the manuals. I hope to find out more about the RAM disk these machines have. I also hope to find out if it is possible to upgrade the RAM to at least 640 KB. At least I managed to upgrade one machine with an 8087. I also dumped the ROM. If interested I can send you the BIN.

Thank you very much in advance!

 

[MindWalker]

I have one of these machines, too. It came with a copy of a boot disc, don't know how much is original but at least it was an Ericsson OEM DOS (old, perhaps 2/3. something?). I'll grab the disc next time I have access to the machine and image it.

Last time I booted the machine it complained about bad RAM, haven't investigated it further.

 

[Ruud]

If there is bad RAM present, then, unfortunately, you have to take the whole machine apart. It took me some time to find out where to start: you have to remove some plastic covers at the top of the machine. From there on it is easy but still a lot of work. Having no intention at all to use the printer, I didn't install it after adding an 8087 to the board.

 

[MindWalker]

Here is the DOS 2.11 disk that came with my machine (IMG + flux from Greazeweasel).





There are some intresting executables (that do nothing inside emulator and have no /? to explain themselves - I can't remember which of these are just the usual DOS 2 commands) and something to do with the Ergo Disk stuff: a file called ERGOS with no extension, and a .DAT that has swedish text inside - I am not sure if something is missing here.



Also ERICLOCK.COM so I presume the machine has an RTC?

 

[Ruud]

Here is the DOS 2.11 disk that came with my machine (IMG + flux from Greazeweasel).

Thank you very much!

Also ERICLOCK.COM so I presume the machine has an RTC?

I have had a good look at the motherboard but AFAIK I haven't seen any battery, so I doubt it. Maybe it is a tool to set the clock speed? But I cannot remember that I saw another crystal or oscillator but that can be overseen.
I cannot promise you anything but I hope to be able to test the disk coming weekend.

 

[MindWalker]

I have a faint memory of seeing a blog post or a video mentioning a battery (I remember thinking that I should disassemble the machine to check that, and later thinking that I'd do it once I start looking for the faulty RAM), but I might be wrong. I have seen the machine only ever listed as a 4.77Mhz but I guess its possible that it had another, higher clock speed as well...?

 

[Lupker]

Hi! I just got 2 Ericsson 8400-005 laptops from my Uncle. Very exciting about these and I would very much like to boot them up!

Both start (screen works). The first one gives me a system rom 50719 / Main memory 512KB OK and the Ergo-Disk is installed. What is this???? Extra extented memory? and then the WAITING...
So I guess a bootable disk is needed. The machine is not recognizing any disks (keeps WAITING), so I guess the diskdrive is not working here.

The other one also system rom 50719 / Main memory 512KB OK and then EXTRA MEMORY ERRORS AREA 0 and 1. Ergodisk is not loaded. and then the WAITING appear.
So I guess a bootable disk is needed. I've tried several DOS 5 1/4 disks but all of them seem to have a boot failure. I guess there disks are bad after 40 years?

I also got a expension unit. Do not know what this is? Extra memory / RAM ? Or something like a HDD ? Type 8413-001. There is also a Flex Disk connector on the laptops. Any idea what this is?

I guess I should open them up and swap the diskdrive / memory to make one good functioning laptop. Any help / manuals or maybe a possibily to make a working 5 1/4 boot floppy would be very welcome.

Gr,
Mark

 

[Ruud]

... and the Ergo-Disk is installed. What is this????

If I understood correctly it is a RAM-drive. I'm still busy figuring out how to operate it.

 

[MindWalker]

Does the floppy drive make any sounds?

I also got a expension unit. Do not know what this is? Extra memory / RAM ? Or something like a HDD ? Type 8413-001. There is also a Flex Disk connector on the laptops. Any idea what this is?

That expansion unit is cool! Can you take it apart and give us some pictures?