Brand new Z88

I've become quite attached to my second-hand Cambridge Z88, too many memories of writing BBC Basic programs at school I guess.  When I found out that you can still get them *brand new* I was surprised.  So I bought one!  It arrived today boxed up with the user manual in the original shrink wrap.

I can certainly recommend the supplier: rakewell.  I ordered it on Friday and the machine arrived on Monday, plus I had a nice chat with their man Vic in the process.  I am continuing to write my own transfer software, it's now at the point where I can reliably back up my Basic programs from the Z88 to my Windows 7 based machines.  Plus I can restore them back to the Z88 as well.  When on the PC, the files load happily into BBC Basic for Windows, even the free trial version.  So I can write programs on my Windows machine, save them and then transfer them to the Z88.  For the PC, I have written a console application in C# that can send and receive in the same format.

I will post the instructions and source code at some point, in case it helps anybody else.  Although it has occurred to me that I'm the only person wanting to back up a Z88 to a Windows 7 machine...  

Z88 Serial Cable

One of the things that was good about retro computers was the User Manuals.  In my Z88 manual, it describes how to make an RS232 cable that will work with its serial port (the port on the Z88 has a non-standard pinout).  So I made one:

Home made Z88 RS232 cable

It was made from bits that I had lying around (as you can tell).  Mostly stuff salvaged from old PCs in fact.  Note the USB adaptor on the end.  It's clunky ... but it works.  I could easily make a better one (one not made from junk perhaps). 

More retro: the Z88

OK, so I've been buying more retro computing from eBay again.  This is the latest:

The Cambridge Z88

I remember that one of my school friends had one of these, it's only taken me a couple of decades to catch up.  So I've set about writing my own transfer software to move data between the Z88 and the PC.  So far I have a BBC Basic program that runs on the Z88 and a C# .Net application that runs on the PC.  Binary files can be transferred, so I can back up my files (including program listings) off the Z88.  Maybe I'll show you the cable I made, it's a serious DIY job.

Brunsviga 18RK

I’ve bought a Brunsviga 18RK mechanical calculating machine, since it is a piece of computing history.  Here it is:


It is awesome and I can report that everything seems to work.  It can’t do negative numbers, so I have enjoyed doing things like entering 100 and then subtracting 150  to get a result of 9999999999950. That’s called underflowing the accumulator, and a bell rings when you do it.

In its honour, I have also written this C program:

#include <stdio.h>
int main(int argc, char *argv[])
  unsigned char test='A';
 return 0;

…which underflows an unsigned char, subtracting 66 from 65 to get a result of 255.  For the sake of completeness I’m printing ACSII code 7 at the same time, so that a bell also sounds.  I’m sorry.