Isn’t that a Space Ship?

Beam me up Scotty! No, not that Enterprise, but the extremely obscure 8-bit British computer from the mid 80’s.

I first remember seeing this computer advertised in some kind of additional “new computers” type supplement which came with a magazine (most likely a Spectrum mag) I had as a kid. I wanted one. The specs at the time were fantastic — being able to display 256 colours on-screen at once, a funky looking built-in joystick and the promise of “obsolescence built out”. Which was quite ironic as it was obsolete before it was even released, as due to manufacturing problems and numerous delays, it was not released until 1985, the year the Atari ST debuted. It just couldn’t compete.

Emulation is the Sincerest Form of Flattery

Enterprise Startup Screen

Enterprise Startup Screen

Some time in the early 90’s I was quite heavily into programming demos and games and the like on the Atari ST. My friend Kev Thacker was also like minded, and we spent many many hours coding and bouncing ideas off each other. At this time emulators just started appearing. Computers like the ST and Amiga were just about powerful enough to emulate things like the Spectrum in near real-time and I had just acquired my first 286 PC at this point, which was where my interest in writing emulators began.

I’m not really sure how it started. I remember Kev had written a CPC emulator (Arnold) on his Amiga, and I decided I wanted to write an Enterprise emulator to see what this machine was actually about, as I’d never actually even seen one. There was something called the “Enterprise Depository” on the web (which itself was a new thing at the time), run by a chap called Jean-Pierre Malisse, which was dedicated to collecting material related to the Enterprise computer. I got in contact with JP and with a bit of to-and-fro he sent me some technical documentation for the Enterprise and put me in touch with some people from the UK Enterprise User Group, who I eventually bought my first Enterprise 64 computer from.

With a bit of work from myself and Kev, we wrote the first Enterprise computer emulator. And in fact the Enterprise emulators available today are based on the source code of our original emulator. I still remember seeing the flashing “ENTERPRISE” logo on the PC screen for the first time.

Out of Memory at Line 10

Fast forward a decade or two, and I was starting to get properly interested in electronics. I always find the best way to learn is to find something you actually want to do using these new skills, and make it happen. I had actually started an HDMI output project for the Atari ST, using an FPGA development board, and actually got it to a pretty advanced state (it actually worked, albeit with a single bit of colour) before finally admitting to myself I didn’t have enough experience with PCB assembly to handle the tiny surface mount components required to actually produce the PCB’s. To that point it had been largely like any other programming — you “program” a chip in a hardware description language, and the connection to the ST motherboard was really just crude wiring.

So, I decided it was time to get some actual assembly experience, and starting with through hole components, too. One of the simplest things I could think of doing was a memory expansion — it just requires a bit of address decoding and a memory chip. This also coincided with my interest in the Enterprise waxing again, so I had a project and a target. This time I’d make a few of these and actually sell them.

It just so happened at this point in time I found a cheap broken Enterprise 64 on eBay, this became my “project” Enterprise. Thanks to the immense Enterprise hardware knowledge of Zozo from the Enterprise Forever forum, it was an easy fix, and the memory expansion project begun.

Adding RAM to the Enterprise is pretty easy — the only difference between the Enterprise 64 and 128 is a (reasonably large) daughter board connected to the main motherboard of the Enterprise via a couple of ribbon cables, which contained an additional 64KB of DRAM. My expansion would be the modern day equivalent of this board, plugging directly into one of the expansion headers of the Enterprise and connecting to the other via a ribbon cable. The project itself was very simple, just consisting of a single SRAM chip (very easy to use — no refresh required as you do with DRAM) and a GAL (Generic Array Logic — an early low gate count programmable logic chip) to handle address decoding.

The Chinese Connection

Enterprise Memory Expansion PCB

Enterprise Memory Expansion PCB

To this point any PCB work I had done ended up with me trying to photo-etch boards myself with ferric chloride and a UV exposure box. A total pain in the… rear end.

This is when I had the revelation that you could actually get small, high quality PCB production runs done by a Chinese PCB fab house for about the price it would cost me to buy the photo sensitive copper clad in the first place. And these boards came with full solder resist, silk screen, through hole plated vias and everything! This to me really was a revelation which changed the way I thought about PCB layout (not that I’d done much). Tiny vias, tiny traces, via’s under chips were all perfectly possible.

The Finished Product

When I got my first batch of boards back and populated the first board, it just worked. I was half surprised and half smug. I mean, there was no reason why it shouldn’t work as such… it’s just expectation that there will always be a mistake somewhere. You just hope its a small, rectifiable one.

So this was my first “product”. I sold a few to various people, mostly on the Enterprise Forever forum, and gained a little more funds to continue my other projects. But more importantly to me, I was gaining some experience.