480z system disk on ebayu

Tony Duell ard at p850ug1.demon.co.uk
Tue Sep 27 13:08:55 CDT 2005

> > I've never seen the floppy drive for the 480Z. From what I can tell, it 
> > linked to one of the serial ports on the 480Z, and used a synchronous 
> > protocol (both ends of the link were Z80-SIO chips). IIRC it's the same 
> > PCB as was used for ther intellegent disk controller in the 380Z, which 
> > contained a Z80, RAM, and the serial chip.
> I think we've been here before :-) Yep, you're absolutely correct - it 
> does use the same controller in the drive. I've got one of the 
> (museum-owned) drives back in the UK, along with the Shared Disc 
> software so that the drive could be made visible across a network (one 
> step down from the full CHAIN network fileserver that I have). One day 
> when I have time I'll try and make it Do Something...
> I'm lacking the connecting cable, but as there are SIOs at either end 
> that shouldn't be a problem to figure out.

The pinout of the 480Z port is known, I think it's on the web somewhere, 
if not I have the manual. There's a 380Z service manual on the web 
somwehre which has a schematic of the intellegent disk controller board. 
I assume it's just a matter of matching up signals, or doing the obvious 
null-modem swap.

> I believe that the 480Z hosting the drive then becomes a decicated 
> fileserver in this setup; it can't be used to run normal programs.

I can't see why it should. There's enough intellegence on the disk 
controller board to act as a simple fileserver, I can't see why it would 
need the 480Z's processor as well. 2 Z80's just to run a floppy drive is 

> The software on EBay would sure be nice though as it seems that's 
> designed to allow a single user to boot CP/M from a 480Z, without 
> futzing around setting up a full network (not all 480Zs come with the 
> analogue side of the network hardware fitted anyway)

Mine didn't....

> > 480Z machines are hard to find now, although there' a plastic-cased one 
> > on E-bay at the momnet, I think. The older metal-cased version (black 
> > painted, like a 380Z keyboard) is, I am told. rarer.
> That's certainly been my (limited) experience. Shame really, as they 
> were pretty good machines - a lot better than much of the other 8-bit 
> stuff floating around at the time IMHO. Somewhat let down in the 

I don't think they were exactly cheap, though....

> graphics department though, even with the hi-res hardware fitted - plus 
> of course they don't have all the nice expansion options of a BBC micro.

No, no second processors, for example. But there was a user port (not as 
good as the Beeb one), and an optional GPIB port.

> (I've got a plastic-cased 480Z set aside for you btw, just in case you'd 
> forgotten!)

When you get back here, I'll have to find time to visit...


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