Amstrad seem to have a talent for producing interesting hardware. Leaving aside the Amstrad PCW --- possibly the most popular CP/M machine in the world (largely because noone knew it ran CP/M) --- they have also produced some other, more exotic devices, some of which I own.

The NC200 is one of the most unusual laptop computers ever made. The NC-series of notebooks --- there were three different models --- ran off consumer batteries, had a full moving keyboard, solid state memory storage and had a battery lifetime of ten to thirty hours. They were based around a Z80 and ran their own custom OS. They have an excellent keyboard, a small but clear screen (80x16 character with bitmapped graphics; I don't have the exact resolution offhand), it's got a decent simple word processor, lots of storage, and can read and write DOS-formatted 3.5" floppies. Boot-up time is nil; press the button and it goes.

The NC200 went out of production in around 1990. See here for more information about the NC notebooks.

nccard-0.1.tar.bz2 10 kB

A tool for extracting files from an NC-formatted SRAM card. Source code only.

The Amstrad e-mailer is a smart phone appliance thing and consist of a chuny desk phone with a respectably sized screen, pull-out qwerty keyboard and lots of buttons. The most recent version, the E3 videophone, has a colour screen with a video camera attached.

There are currently three different models. The E1 is no longer available. The E2, one of which I own, has got an ARM7TDMI processor with 8MB RAM and 8MB flash and runs a proprietry embedded OS. The E3 has an ARM9TDMI with DSP and more memory, and runs Linux (although not in a useful way). Both devices have a mysterious EXP port on the back that turns out to be a serial port in disguise, although to access it on the E2 you need an RS232<->TTL line level converter, which can be used to replace Amstrad's firmware with your own custom software. See here for more information on the e-mailer hardware.

pblq's Github repository

pblq, my client for the e-mailer's PBL boot loader. pblq allows you to upload and download data, read and write the NAND flash on the device, and also provides some other functionality useful for developing for the e-mailer. It should work on both the E2 and the E3, but most testing has been done on the E2.

pblq is licensed under the BSD license.

In order to talk to the E2, you need the appropriate cable. Irritatingly, while the E2 has a serial port, it runs at TTL line levels not RS232 levels. This means that if you're going to connect it to a PC, you need a line level converter.

One approach is to build a MAX232-based interface board, which I've done, but this is inconvenient as it requires powering. The other alternative is to find an appropriate mobile phone cable and hack it; a lot of mobile phones use a similar communications scheme. This is what I'm doing. It's a lot easier --- and considerably neater --- than building your own level converter on breadboard.

Here are pictures of the cable I'm hacking. It's a Nokia 5100 cable bought from eBuyer for about three pounds. In order to make it work on the E2, the mobile plug gets snipped off, and a 2.5mm jack gets attached. You need to connect:

  • GREEN (ground) -> sleeve
  • BLUE (tx) -> ring
  • WHITE (rx) -> tip

Then just plug it in and it works.

The front of the PCB:

[Image of the front of the cable's interface PCB.]

The back of the PCB:

[Image of the back of the cable's interface PCB.]

The entire cable:

[Image of the entire cable.]