Re: The Apple ][ was cool!

[Leonard Erickson <shadow@krypton.rain.com>]

Roy Miller wrote:
> 
> william strutts wrote:
> 
> > > No. EMM only works with the 80206 or higher CPUs.
> >
> > It seems to me I heard of large RAM cards for 8088 machines
> > but I could be mistaken.
> 
> But they weren't EMM. They were EMS.
> Two very different memory management systems.

EMM is the name of the *driver*. As in EMM386. Both XTs *and* 286
systems used LIM/EMS type *hardware*. 

The 286 had extended memory, but *using* it was a pain. It required a
*reset* of the CPU after each access as the 286 had no way to switch
from protected mode back to real mode. This lost interrupts among other
things. 

Expanded RAM is available on *all* PCs. It requires special hardware for
8088/8086, 80186, and V20/V30 systems. On 386 and up system, it can be
done in software.

Extended RAM is available on the 286 and up (*if* the extra hardware is
there to support the switch back to real mode), but isn't very well
implemented. Only on the 386 is it a decent choice.

> > I beg your pardon.  The 6809 machines could multitask using
> > OS-9.  The TRS-80 Model 16 could multitask using Xenix.
> > It had a dual processor if I recall:  a Z80 for I/O and a 68000.
> > The DEC Professional was a PDP-11 based computer
> > and could run various OS's designed for that machine.  Then
> > of course you have the Sun's and other workstation manufacturers
> > that build Unix boxes.  The Amiga released in 1985 could
> > multitask.
> 
> On one was building spreadsheets that were 512K or bigger in 1984 on those
> machines. You don't seem to read very carefully, do you?

You could do *that* on a TRS-80 model 4 with an add on memory expansion
setup. 512k of RAM, bankswitched. Multiplan would use it.

> > Microchannel
> > was dead out the box.
> 
> Really? Hmmm, then how did IBM sell millions of MC boxes for years?

Heck, at least two *other* companies licensed MC to use in their clones!

> > and the only licensee of it was Tandy with
> > the 5000 series.
> 
> There were other machines with MC.

Tandy was one of the ones, I can't recall the others.
 
> But EISA was more of the same. A kludge of a kludge of a kludge. Not real
> creative the cloners, were they? At least Microchannel was creative.

Hey, EISA works just fine. And a number of early PCI slots were done via
an EISA-to-PCI bridge!
 
-- 
Leonard Erickson (aka shadow{G})
 shadow@krypton.rain.com	<--preferred
leonard@qiclab.scn.rain.com	<--last resort