Date   : Wed, 23 Sep 2009 19:20:11 +0100
From   : theom+news@... (Theo Markettos)
Subject: OT: RM Nimbus

In article <4ABA4E46.2010204@...> you wrote:
> Ours ran MS-DOS, so would run any MS-DOS software, provided it *only* 
> used standard documented MS-DOS calls. You could enhance compatibility 
> by executing "setpc ibm" which did I know not what, and allowed some 
> PC software to work. "setpc rm" switched back into Nimbus mode.

They had better graphics than a contemporary PC, perhaps to compete with the
BBC Micro (I think it was about EGA quality, which wasn't that cheap at the
time).  The graphics weren't accessible in IBM mode - I think it dropped
back to CGA.

At school we had one receiving weather satellite pictures with a program
called NimSat... don't know how the hardware connected but I might still
have a copy on floppy somewhere.

> There was apparently a version of MS Windows that ran on the Nimbus, 
> but we didn't have it at our school.

The disc I have/d with Windows 1.03 is a special version for the Nimbus,
though it may be a network-installable version.

> The early Nimbuses were quite chunky, and had lovely, largeish 
> paper-cone speakers for the 3-channel sound, and had an old IBM-XT 
> layout keyboard. The later ones (dubbed "PC186") were slimmer, with a 
> crappy piezo speaker, but a more modern AT-layout keyboard (i.e. the 
> ones common on PCs now, only without the extra Windows keys). AFAIK, 
> the differences were only cosmetic.

They had Z-Net, a coaxial LAN a bit like ethernet (used the 8530 SCC I
think).  There was also piconet, another serial network using the other half
of the 8530 for connecting peripherals (like data loggers).  There were some
Z80 peripherals onboard (Z80 SIO?), presumably due to their previous Z80
machines.

There was an internal expansion bus connected by ribbon cable - mine had a
6522 parallel port and a uPD7210 analogue port so it could pretend to be a
BBC (with the drivers on my page they could be used in BBC BASIC).  The
floppy controller was also on this bus... it was a slightly unusual chip but
I can't remember which.

Motherboard was mostly ASICs as I remember so not terribly interesting (half
a board sat in my junk box for ages but there weren't many useful chips
to desolder).

The manual refers to Microsoft Networks as the OS for running networked
machines.  I think this was some version of DOS, but I've never found it
(and this was a decade before MSN the online service).

I also had an RM 386 PC... bog standard 386SX16 clone, but with a magic
string in the BIOS so RM's BBC BASIC would work (I suspect this was easily
hacked).  I once got Linux, X and Netscape 3 running on this in 4MB of RAM. 
It wasn't fast :)

Still have an RM Pentium 75 acting as firewall/dialup server, with the
original classroom Win 95 software still on the hard drive.

Theo