Archive for the ‘NCR’ Category

Siemens Nixdorf PCD-3 Psl/20

October 8, 2020

Recently, on Ebay I discovered a variant of the NCR 3125 that I did not know: the Siemens Nixdorf PCD-3 Psl/20.

I did not buy it, but from the picture it seems quite clear that this is, in fact, a NCR 3125. Also, the name seems to hint to the 3125′ 80386SL CPU at 20 MHz…

Update (21.03.2021): Actually this is a NCR 3130, not a NCR 3125. It says “SNI 3130” in the boot menu and has the backlit display. Which I know because now I own one.

NCR Safari 3115

February 27, 2020


Recently, on ebay, I stumbled upon another NCR mobile, pen-based computer. In contrast to my beloved 3125s, I have never heard of it.

It looks like the older, smaller, much uglier brother to the 3125, but it is not. It is the much rarer, smaller, much uglier, younger brother of the 3125: the Safari 3115.

“Safari” already hints to the time it was released, because Safari is the family name of the AT&T mobile computers. NCR was taken over by AT&T in 1991/92, so this release must be later than that.

Now, the model designation 3115 puts it in the NCR 3000 family, below the 3125, but the “3000 family” was always a marketing lie as the computers in it differ a lot architecture-wise and OS-wise.

The operating system of the 3115 was Windows 3.1 with pen support. The RAM seems to consist of a DRAM card that is accessible via the interface bay. Mine is a Samsung 4 MB model. It is labelled “ICMC V4.1” which is the same as PCMCIA 2.0.

There is an “unofficial NCR (Safari) 3115 support page” which holds most of the information on this machine, but it seems to updated last in 2000…

It weighs 1700g, so it is even 200g heavier than the A4-sized 3125… And although the outer area of the 3115 is smaller than the one of the 3125, the outline volume is probably about the same or even larger!

The Computer History Museum even has a docking station called “CommStation” for the 3115.

I did not think that this machine even deserves more research, because, boy, it is ugly, and because there were a lot of Windows-based pen tablets out there after 1991.

However, I opened the case to see what’s inside because some things (like the concrete CPU model) are not even known. And I have to say, the inside is more advanced than what I thought it it would be.


What I was surprised first was the fact that the computer seems to be at least splash-proof. There is a thick seal in between the case halves, and most of the interfaces are put behind rubber plugs. There is not even an electric interface connecting the machine to the docking station, but an array of infrared LEDs.

The second suprise was that most of the weight seems to be contained in the display which is secured in a metal case. The PCB is not very large, the case not that heavy.

The final suprise was the “harddisk”. It is not a harddisk, it is basically the second generation prosumer-grade SSD in form of a SunDisk(sic!) SDI-20 20 MB SSD with a date of 1992-1993. The first generation was developed by SunDisk (now SanDisk) for the original IBM ThinkPad in 1991. It had a capacity of 20 MB and costed $1000. Obviously, an SSD is much more suited for a rugged pen-based computer than a rotating harddisk.

Other things I found inside were: an Intel 80486SX CPU and 4 MB of soldered RAM.

So, here is my final verdict: This was an attempt to created a rugged, small, pen-based Windows tablet. Unfortunately, it is way too heavy and ugly. Although I don’t know the original price, it probably have not been cheap. It is more interesting that what meets the eye and it is a very, very rare thing.

Technical Data

Manufacturer: NCR
Model: Safari 3115
CPU: Intel 80486SX@25 MHz
RAM: 4MB (8 MB max)
HDD: 20-40MB
Weight: 1700 grams
External dimensions: 23cm*23cm*7cm
Pen: Cordless 1 button digitizer pen made by CalComp Inc, transmits on R/F ranges 0.0576Mhz and 0.0614Mhz, runs on 4(E 393 buttoncell batteries)
Display: 6.25″ Backlit Monochrome VGA
OS: MS-DOS 5.0/Windows 3.1 with pen support
Interfaces: 1 RS232C DB9 serial port, 1 Centronics 25-pin Parallel port, 1 PS/2 Keyboard port, 2 PCMCIA-II expansion slots, 1 PCMCIA-1 memory card slot, 1 Infrared communications/docking port, 1 external power/charging connector
Battery: 9.6V (NIMH) 1200mAh, 1.2A, good for 4hrs per charge?
Released: 1993
Initial price: ???


NCR 3125 under PenPoint

December 3, 2017

Yesss, finally. After having a presentation on GO and PenPoint and a booth on “A short history of Mobile Computing” at VCFB 2017 (I’ll soon report on both) with a NCR 3125 and an EO 440 but no working computer running PenPoint, I finally acquired another NCR 3125. And this time running PenPoint!


Oh, yes, plus a (probably) complete set of PenPoint developer documentation (only 2 volumes are missing).


Plus some replacement tips for the WACOM pen (comes in handy as the tip of the other pen disappeared).


You’ll get some photos soon and then I can submit one to Wikipedia (for their PenPoint entry).

My plan is to extract an HDD image of PenPoint and provide it on this blog. I think some people might be interested in that… If this image from is true also for my model, the HDD is a 2.5″ PrairieTek Prairie 120 IDE model (20 MB). So this sounds manageable. Update: Yes, the HDD is the model above. I was a little bit confused upon opening the computer when all I saw coming from the HDD were 2 flat flexible cables (I was looking for IDE connectors). Upon closer inspection I noticed that the HDD controller (usually screwed on top of the HDD) was mounted detached positioned next to the HDD body obviously to make the package more flat. You can see this in this picture quite well, the HDD is the black box on the top left corner plus the controller on the right:


(Picture taken from, in this case this page on the 3125)

The controller, of course, has the IDE connector.

In contrast to my old 3125, this one is equipped with 8 MB of RAM. I wonder whether this is required by PenPoint. Hmm, all the early mobile computers being able to run PenPoint (3125, EO 440, IBM 701T) had minimally 4 MB of RAM, so probably not. BTW, the PenPoint is a 1.0a version. Sounds quite early.

My first impression of this version of PenPoint on the 3125: quite slow! You have to be patient to work with this system… The computer came with a bare PenPoint, no additional software seems to be installed. The most fun part after the tutorial on how to use PenPoint is the feature to getting the gestures explained and then being able to train them.


Upon playing with the new system I realised the first time that the on/off switch of the 3125 is located on the (detachable) battery pack, so no switching on the system without a battery. Even the manufacturer’s name and the model name on the front is printed on the battery. I never saw a battery made an integral part of the system so clearly 🙂

Oh, yes, and a word of advice on starting an NCR 3125. Sometimes (e.g. when the battery was dead), it seems to employ a strange double booting procedure (probably due to the usual dead battery). First, the “BIOS” part of the computer is started and the memory tested (namely the main PC memory (640kB) and the extended memory). The computer will complain about invalid CMOS memory content and stuff and will allow to enter the BIOS settings. But do not worry. Simply exit this stage, and the real OS booting process will start. Again with a RAM test, but this time including 3 memory parts. For exiting the first stage your pen needs to work (maybe a keyboard will do, too). Clicking on the “<EXIT>” text usually does the trick.

NCR 3125

May 29, 2014


This mobile computer from 1991 is the second pen-based device (after Grid’s Gridpad from 1989), the first one with a separate pen (although it beats the Gridpad 2050 or Gripad SL by only a few months if any) and the first one from a big manufacturer. It is also one of the most expensive mobile computers with an initial price of a hefty $4795 (about $8200 in 2014 numbers). Finally, it is one of the few mobile computers designed in Germany (by NCR in Augsburg).

Operating systems-wise the device is very flexible because it came out at the right time. As a PC it can run MSDOS plus NCR’s proprietary “PenOS”, a.k.a. the software that let you use the pen as an input device to enter text in a DOS environment. From 1992 onwards it could execute also (Microsoft) Pen Windows. Finally, even GO’s PenPoint was available for this computer. Some people even got (PC-)GEOS running on it.

My machine (as far as I can see) has only DOS + PenOS. If you happen to have PenPoint for it, I would be very happy…

The model number of this device is 3125. According to some old NCR information (see links below) this makes is a member of the NCR 3000 family that spans from this tablet and a notebook all the way up to a multi-processor, 100,000 MIPS big iron computer system under Unix. As all these systems do not share the same architecture or even the operating system, that’s quite a stretch…

The design of the device is very sleek; it looks very streamlined and timeless. The pen for example is neatly contained in a small hidden compartment at the front. It was rewarded a “iF product design award 1992 – Best Of Category”.

There seems to be a successor to this model with the Model 3130 NotePad in 1992. The 3130 had a backlit screen and a 40 or 60MB HDD and comes with Pen Windows. The weight increased by a pound. The price was about $4000.

I am very unsure on the fate of this machine. It was expensive, not often mentioned in the news, and so I assume it was not very successful. Maybe it was also subject of the turmoil following the takeover by AT&T in 1991/1992.

Technical Data:

  • CPU: 80386SL @ 20 MHz (has about 15 MIPS)
  • RAM: 4MB
  • HDD: 20MB
  • Weight: 1500 grams
  • Pen: passive
  • Display: LCD 640 x 480, 16 gray shades
  • OS: MSDOS plus PenOS or PenPoint or PenWindows
  • Interfaces: VGA, keyboard, RS232C, Centronics, all via a “I/O Connector Adapter”
  • Released: 1991
  • Initial price: $4795