Category Archives: Retro Tech

Toshiba T3100

6fd47f77257fcea0341953d444ca31ceThis is a bit of a mundane machine to me really. An AT class portable from Toshiba.

Not a laptop by some peoples rules as it needs a mains lead and cannot run from batteries.

I quite like the glow of the orange mono gas plasma display. Was this a dead end technology? Not sure… Isn’t this the same basic thing as the plasma TVs?


Wang Laptop

6b435e55d1efa322d29e755628f7b57eThis is a really unusual one.

Wang released their forray into the laptop market in 1985 and to be honest, it doesn’t seem to have made much of an impact. Just looking around for information on the ‘net doesn’t yield much and that must be saying something.


Technically it’s an x86 class machine with 640kb of RAM, and a mono LCD.


The unit is quite large, a goodly sized lap is needed here but for the period it’s quite good. Compaq’s sewing machine sized portable is not too far in the past and IBM’s PCAT is still in view.

The screen serves as the keyboard cover and opening it reveals a ful sized keyboard with nice keys full travel. It also reveals a thernal printer.

1de2a76c1adf95a3835bc0a7f62bcb6cInternally there is a hard disk drive but no floppy. An external drive is provided. I suppose that the logic was that you only plug in the floppy when you need it, the rest of the time you will be working from the hard disk.

Another unusual feature of this machine is the the external floppies (both 3.5″ and 5.25″ were available) are linked using SCSI. That’s very unusual. As this is before the advent of USB, SCSI was a sensible choice for removable devices as the connectors were tough and it could haul the distance without problems. Still and expensive and unusual choice. The first IBM PC floppy card could take two external drives and there just use the normal floppy bus.

Power is provided by a weighty external PSU and this “T”‘ off to power the floppy.


Retrochallenge 2013 – July 31. He shoots…

c6fcf7c869428cc478bd4e24cd345e56I have decided to enter Retrochallenge 2013. A spledid competition that runs throughout July every year.

Accoring to the website…

In a nutshell, the RetroChallenge is a loosely disorganised gathering of RetroComputing enthusiasts who collectively do stuff with old computers for a month.

And I have decided to use this as a dig in the ribs to try and get the Liberator going.

I’m not sure how I’ll do this blogging lark but I have a go while it’s fun 🙂


He Shoots… He misses…

So as Retrochallenge draws to a close for another year the Liberator is still not running.

One the plus side I have learned quite a bit about this interesting little machine. I have foubnd another one in the wild (well in Wales) and I have a certain admiration for its designers who gave the I/O board has its own processor to look after it. They gave it S5/8 ports instead of RS232. That should have been a great move. Sadly no one else followed.

It has memory cartridges, a bit like the USB memory sticks we take for granted and stacked RAM which usually looks like a dog’s breakfast but in this case uses eligant sockets.

This really is a nice machine. It just doesn’t work…



July 28 2013. Time is running out.


Things have not been going quite as swimmingly as I had hoped. Replcing the flexi cable between the two boards did not bring the beeps back as I had thought and so I’ve been sniffing around but really I’m just getting the lie of the land.

This is what I think… There are two main boards (I’m not counting the keyboard PCB. It’s not fair the passive components I know but that’s just the way I am). There is the lower board pictured above (ironically). It has a microcontroller with a piggybacked EPROM, two S5/8 ports, the keyboard connector the LCD and other bits and bobs. I’m calling this the I/O board.

The upper board has the CPU, the piggy back RAM and the main ROM. I’m calling this the CPU board.


The two boards are connected via the flexy PCB you’ve read about earlier.

The I/O board has the battery connector and so the CPU board is not a lot of use without its flexy umbilical. I’m not sure how far I should be able to get just playing with the I/O board. My guess is not very far as you don’t want the I/O board doing much more than initialising its peripheral controllers without the main CPU’s say-so.

This backs up what I’ve found. Without the CPU board the I/O doesn’t seems to do much. The problem is that it doesn’t do much with it either.

I do get a slight click from the piezo beeper when I connect a battery but that’s about it.

Hmmm. ‘scope time…




July 25 2013. Silent (not) running.

I mentioned in my last post that I’d had a problem with the flexi and made contac with another Liberator owner. Well it turns out that said Liberator owner, Peter, had an almost identical cable in his spares box and sent it over. Retro computing has some of the most generous people.

tonight I’ve carefully modded it to make it fit but I’m still not getting the old beep :-(. I seem to be getting 5V on the logic board but no signs of life.

time is running out but the saga continues.



July 21 2013. It’s all gone Pete Tong.

Things have not been going to plan just lately. It started very well. The new batteries were giving me a reassuring Beep. I opened up the case to get some more photos and to look for clues.

The problems started when I unplugged a flexi-pcb type ribbon connector or more correctly plugged it back in. There was a neasty cracking sound and more no more beeping.

I have clearly cracked the ribbon.

More bad-ish things in that my Mac Mini has decided that it doesn’t want to run in this hot weather and so I can’t get to my photos etc.

More of my computing time hace been spent getting another machine up and running. Ironic really that I am surrounded by machines but most are too retro to use for email, web editing, photos etc. (Yes I know you can connect a Spectrum to the ‘net but come on… Seriously)

I now have an old Dell rackmount server as my PC running Ubuntu 🙂

A bit of good news came in the form of an email from another Liberator owner, Peter, from Wales who has leapfrogged my efforts with some wonderful information an old school cunning. He is really on the ball with this and leaving me in the dust but a very welcome contact.

When I can I will sort out another cable and be back on the trail.


July 16 2013. More batteries.

I’ve found a set of batteries 🙂 Woo Hoo.

I’ve soldered them onto the PCB and fitted them into the batter pack. I’m back with the Beep now.

More investigation to follow.

July 10. 2013. Batteries.

The Liberator has a removable battery pack that was filled with four very fluffy batteries. I disposed of these very quickly, cleaned the board and tried to see what was what. An interesting feature is that the battery pack contains its own charging circuit so the 9V DC power supply plugs into the battery. I haven;t come across any other portable computer that does it this was. All of the others have the DC socket as part of the laptop. That’s curious.

These days you can’t get NiCd batteries any more and so I’ve been thinking of what to do.

I’ve taken the PCB layout of the charger board that’s in the battery pack and drawn what I think is the circuit diagram.


The key component here is the LM317, a voltage/current regulator, which appears to be rigged to limit current. A freind at work suggested that if it’s in that state I could replace the NiCds with NiMHis. Their life wouldn’t be great but they would work.

I’m not sure what to do yet…


Cambridge Z88

03c5e984b174a7d79b66712afd665797The Z88 was launched in September 1987 and is, in my opinion about the pinacle of Sinclair design. It’s a compact, portable computer on the go.

Is has a Z80 processor, popular at the time. The decent size keyboard is reminicient of the Spectrum but a lot better. It doesn’t have much travel and stops abruptly but you could certainly type quickly and accurately for quite a while.

Above the keyboard is a small LCD that goes the whole width but is onlt about 2.5 CM high. There is no back light.

The integrated software is called “Pipedream” and has a word processor, spreadsheet and the other bits and pieces this class of machine from the UK sported at the time.

Despite its CMOS Z80, the Z88 could address a whopping 4MB of memory in 256 x 16k pages and EPROM and FLASH memory cartridges are available.

Sadly mine is on the blink at the moment, I suspect the keyboard as a reset has it skipping and dancing but the double shift key start and shutdown isn’t working.


Amstrad NC200


The Amstrad NC200 is small portable computer released by Amstrad in 1993. It follows on the heels of its older brothers the NC100 and NC150. It has the same A4 footprint as its predecessors. Unlike the NC1000 It has a hinged lid that covers the keyboard and opens to reveal a backlit monochrome LCD screen the angle of which can be adjusted to a comfortable viewing position.




The keyboard has five rows of full-sized keys but doesn’t have space for a number pad though it does have cursor keys. It also has five coloured keys. A Yellow function key. A green key marked “Calc”. Red labelled “Word”, blue, “Diary” and white, “Spread”. Holding Function and pressing one of the coloured keys will take you into the application written on the key, where you left off. This is very handy if, for example, you are using the word processor and need to do a quick calculation. Hit Function Green and you are in the calculator. Do the maths, hit Function Red and you are back in the document, where you left off. Groovy.

On the right hand side of the unit is a 720kb 3.5 inch floppy disk drive and a small slot marked “MEMORY CARD”. To the rear is a co-axial socket for DC power, a 25 pin parallel printer port and a 9 pin RS-232 port. The left hand side is blank. Underneath is a cover for the five C-cells. Another for a CR2032 battery that retains the RAM when you change the batteries. There is also a rectangual cover, secured by a screw, the purpose of which I haven’t established yet.

Getting started.

When you first power up the NC200 you are presented with a graphic menu. It shows the date and time and a picture of each option, word processor, spread sheet, games, calender, diary etc.


The word processor.

The word processor is quite a capable little thing for the period. It can search and replace, mark, copy and move blocks. Sadly there doesn’t appear to be an “undo” function as I’ve just found out to my cost. It does open a new line at the bottom of the document when you try to go down past the end of the document. what a nice touch. There is a spell checker, which doesn’t know the word Amstrad, but is easy to use. When you want to stop typing, just hit the “Stop” key and you are taken back to the word processing menu. You don’t need to save, it’s done it on the fly. That’s very nice.



There is not much to say about the calculator really. It is graphical with an image of a roll of paper that shows a history of calculations as you would expect. One curious feature is that some keys on the main key area have numbers and operators printed on them. You must use these keys and not the number row at the top of the keyboard.



I’ve not had much chance to get into this. It looks a bit quirky but considering that this is a Z80 machine with limited memory, any spreadsheet is an achievement.



I’ve been typing this review on the NC200 and I must say I quite like it. The keyboard have full travel and a great feel. I find myself thinking that this thing is from the days before Windows took over. It is text based but it does a wonderful job of it. If you wanted a light portable word processor, with good battery life this was a great choice.

Amstrad NC100


The Amstrad NC100 was released in 1992 by Amstrad as an all rounder for word processing, spreadsheets etc. The kind of run of the mill tasks most professional people wanted.

It is about the size of an A4 page with a good sized keyboard with a nice action. The screen is a small LCD that doesn’t have a backlight and if my unit didn’t have an intermittent fault it would be splendid!

The Wikipedia article is a good source of information here.

Thorn EMI Liberator

c6fcf7c869428cc478bd4e24cd345e56The Thorn EMI Liberator was developed in the UK in the 1980s for use by the British Civil Service. The idea was to give the civil servants a portable text processor that they could carry around with them for taking notes. It’s an unsung machine and has dropped off the radar for many. In fact it never made it onto the radar for most of us.

The Register have done a series of well written and researched articles that you can read here, here and here and so I won’t go over the old ground. I couldn’t hope to do as nice a job as Tony Smith.

My Liberator looks a little weary. It has no badges, the handle/stand is missing and the battery pack was decidedly fluffy. However it’s nearly thirty years old an I forgive it.

It’s an interesting little machine. About the size of an A4 piece of paper and around an inch thick it’s slightly bigger than a Sinclair Z88 or an Amstrad NC100.

I read that it runs CP/M-80 though I think the text editor is all encompassing and so you can’t see the OS. I say “I think” because mine just beeps but there is no screen output. The keyboard has a nice feel and the keys are a good size. This should make typing easy. Time will tell.

One thing worth noting is that instead of the standard RS-232 ports common at that time, the Liberator comes with a pair of S5/8 ports. These were intended to be a simpler version of RS-232 but they didn’t catch on. Nice try though.

6fd0a457b2a93975c2b956869ecab35bCuriously my machine came with an Epson PF-10 serial floppy disk drive. There is a Dymo label on the back of the Liberator identifying which port to connect it to and a cable to convert from the large S5/8 port to the smaller socket on the back of the PF-10.

Files and Documents

Here you can find the technical reference manual scanned and converted into PDF format.

For practical reasons it’s in several parts.

 Telefunken Reference Manual (German) Part1

 Telefunken Reference Manual (German) Part2

 Telefunken Reference Manual (German) Part3

 Telefunken Reference Manual (German) Part4

 Telefunken Reference Manual (German) Part5

 Telefunken Reference Manual (German) Part6

 Telefunken Reference Manual (German) Part7

 Telefunken Reference Manual (German) Part8

 Telefunken Reference Manual (German) Part9

 Telefunken Reference Manual (German) Part10

 Telefunken Reference Manual (German) Part11

 Telefunken Reference Manual (German) Part12

 Telefunken Reference Manual (German) Part13

Osborne 1

89aab638ca04b67e9f6e3ba51b25e337The Osborne 1 is reportedly the first commercially successful portable computer.

Portable is a relative term. Today it seems enormous, it weighs 23.5 lb and despite it having a carrying handle it would be an ambitious person who walked more than a few tens of meters with it but in 1981, when it was released, computers were either three box affairs such as the IBM PC 5150 or large all-in-ones such as the Superbrain. So this was quite an improvement.

If has the popular Z80 processor, the mainstay of the non Apple business computers of the day, a pair of full-height 5.25″ single sided, single density floppy disk drives and a built in 5″ screen.

I got this example in 2008. It is one of the earlier models as you can see it has a the flat ribbon from the keyboard to the main unit and the clips that hold the keyboard in place when travelling are on the side of this unit rather than on the top and bottom as on the later 1A model.

When I first got it there was a sticky return key a sticky floppy drive and a couple of burnt out capacitors, one on the main board and another in the power supply but they were quickly dealt with and now it’s working quite happily.

It’s a nice machine and very capable for the period. The only real drawback in my mind is the disk capacity, at around 80kb it’s really not enough. There is a lot of information on the web about this machine and it’s very easy to get to know.


Telefunken Telecomp 5200

1e25690a7dd68b8a1e763f4bfa7e33c5I recently picked up what was said to be a Telefunken Telecomp5200 machine in an unknown state. I drew a complete blank when it came to finding out about this machine but the price was right and I though worth a punt. First of all there is a big 70s/80s style terminal but the vendor said that this was the system itself – curious. Then a pair of 8 inch disk drives in an enormous box and an analogue joy stick.

There were also some disks and manuals. My fist suspicion was that there was a computer in the disk drive cabinet and the terminal was just that. The disk cab has a 25 way D-type connector often used as a serial connector on systems of this vintage so it could be possible. However, a quick look inside the case shows that it just contains disk drives and a PSU. Hmmm. At this point I should point out that there is a technical manual but it is in German and I am not.5240fe0baaf8218c503b0f734eb295a9

Next I removed the front cover on the Terminal (labelled Terminal-52 on the back – a VT-52 emulator perhaps?) and revealed a large card cage stuffed with cards, CPU RAM, disk controller etc. A big clue is the name Ontel on most of the cards. Haha, Ontel made 8080 based business computers in the ’80s and ’90s and did OEM deals with the likes of Telefunken. So this is most likely a Telefunken badged Ontel OP-1 but which model? I’ll work it out soon.

Next, time to try powering it up. At this point I didn’t have a cable for the disk drive so that wasn’t in the picture yet, so just the main unit to try. I know that these old systems can get eggy over the years and the capacitors in the PSUs go skywards when pressed so I wasn’t taking any chances.
I put the unit on a stool in the garden before giving it some power. I wasn’t scared of physical harm, I just don’t want my kitchen smelling like someone has died. Anyway, flick a switch, there’s a beep and the fan starts. Whoopee – it’s alive-ish. So far I just get a raster and some vertical lines suggesting the size of the character cell. Not a bad start for kit that’s not been on for 20 years. Having read through a few hastily translated bits of the technical reference manual I felt that I knew enough to try and get the floppy drives connected. I wasn’t given an original cable but looking around the back of the card cage and at the drives themselves it looked likely that they needed a 25 Way cable (the manual didn’t say). What about disk drives? Fingers crossed.

Powering up the drives without the cable seemed OK though they did sit spinning. 5 1/4 drives don’t start until they are needed (usually) but I don’t know what 8 inch drives generally do. Switched everything off. Plugged in a cable. Disks on. Main unit on…. Drive light comes on for a bit and then goes off. Whoopee. This is repeatable 🙂 I have since tried a floopy in the drive and get the same behaviour. I can’t get it to boot but I’m delighted to have got it this far.

Changed the caps.

07a86922c133688605321f2f8799bbd8Next I worked my way through the boards in the card cage replacing the electrolytic capacitors on all of the boards, twenty five in all. It’s quite common for old age to get to them and it won’t do any harm to change them. A little more progress. took a closer look at the Telefunken and noticed a burnt track on the logic board. As it goes under one of the logic chips (4 to 16 line decoder) that chip is going to have to come off in order to repair the track.

I’ve been wondering whether or not the machine should put up a short message on boot up. Mine doesn’t and I don’t know if it’s because its broken or because I don’t have the drives attached. An entry at shows the BIOS as only
occupying 256 bytes or memory, enough to boot from floppy. Would they waste some on “Hello and welcome”?. The Amstrad PCW series doesn’t say anything until it has booted so it is a possibility. Scanning in the manual I have started scanning in the German technical manual. I really need some clues and that seems to be the place to start. The plan is to scan it, OCR it and then translate it into English. So far I have about two thirds scanned. The scanner is part of a Brother MFC-J8250 multi-function scanner/printer/copier. It can scan to PDF file on a memory key and works really well.
I’ve found OCRTools on the Apple App Store which can OCR from a PDF file but not only that. It can also translate from German to English at the same time. An amazing little piece of code. Not only does it work really well but it’s incredibly cheap at just £1.99. Amazing.