Amiga Sidecar (was Re: Computer auction in Vancouver BC)

Tony Duell ard at p850ug1.demon.co.uk
Thu Dec 3 14:08:39 CST 2009


> 
> Ethan Dicks wrote:
> > Very nice.  I have a couple of 8-bit and 16-bit Bridgecards, but never
> > ran across a Sidecar (and couldn't afford one when they were new, but
> > didn't really need one then, anyway).
> 
> Interesting! I've got a Torch Graduate, which is an almost identical concept 

I've got one of those somewhere. From what I rememeber it'll boot normal 
PC MS-DOS, byt video output is done by having the approriate BIOS 
interrrupt send stuff back to the Beeb over the 1MHz bus. So PC software 
that does direct writes to video memory doesn't run on it.

I think this is the machine that uses a curious feature of the BBC micro 
that if NMI (?) is asseted after a hard reset, the Beeb executes a 
routing in the 1MHz us address space. Meaning the Graduate doesn't need 
any special ROMs in the BBC micro, the boot ROM is built-in and accessed 
over the 1MHz bus.

> So, were there "external box" PC-a-likes for other vintage systems? I know 
> there were some internal boards for various machines...

HP did a 286-based DIO card for the 9000/200 series. I assume it ran 
MS-DOS, but probaly not a PC-compatible version (this is a DIO card I've 
never seen and would like...).

Wasn't there a thing cammed MacCharlie? A box that sat alongside a 
classic Mac and connected to the serial port (?). It had a 5.25" drive 
built in and would run PC software using the Mac keyaord and display.

-tony




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