DR-DOS

[Liam Proven]

On 22 November 2017 at 11:25, Peter Corlett via cctalk
<cctalk at classiccmp.org> wrote:
> On Tue, Nov 21, 2017 at 08:15:00PM +0100, Liam Proven via cctalk wrote:
> [...]
>> A file-based virus could escape _if_ the VM had access to the host
>> filesystem. But mine don't, partly because it's moderately hard, partly
>> because it takes a _ton_ of RAM in DOS terms.
>
> Not really: QEMU can be configured to add a Virtio device, which exposes a host
> filesystem via 9P (the Plan 9 filesystem protocol). A DOS device driver for
> that would be of comparable complexity to a CD-ROM driver.

Which itself takes a ton of RAM, in MS-DOS terms.

So far, trying VMware Player and VirtualBox, you only seem to get
about 48 kB of so of usable UMBs, if you want a page frame as well.

CD support takes, well, about that. Circa 35 kB or so.

Network support is about 100 kB of RAM -- a hell of a lot for DOS.
Back then, the fact that the Netware client could run partially in XMS
or EMS was a big competitive advantage. The MS client was lardy, and
that was with efficient little protocols like NetBEUI. Add something a
bit chunkier like IPX/SPX or DECnet, and it became basically
impossible to keep the whole thing from eating a significant chunk of
conventional memory too.

TCP/IP basically postdates the MS-DOS era, in PC terms, and it's
Bloaty McBloatface. Couple that with needing SMB/CIFS support, and you
can be looking at something horrendous like 150 kB of RAM.

And you want 9p?!

I mean, be my guest, go implement it, but to talk to VBox or VMware,
you need CIFS.

I've tried QEMU and KVM for work, just before I was off sick.

My reaction is roughly that of Ford Prefect to Vogon poetry.

It might be OK if you want a server hypervisor, which I don't,
personally. But then, earlier this year, my reaction to modern server
VMware was broadly similar. Horrified incredulity and appalled
revulsion.

Now I have it working, I concede, it actually _works_ quite well. I
can run a bunch of VMs with a total of about 18-20GB of allocated RAM,
concurrently, on a host machine with 12GB of RAM, and it _works_, and
amazingly it's quick.

(Of course this is a play/text box, and they're all unloaded.)

But setup... *Screams and writhes*

KVM? Well, it's every big as unpleasant or more so, but it's agonizing
in a Unixy way, which is at least more familiar, so through the
suffering and the tears, I could just about see enough to get it
working.

But only someone who thinks that Emacs or Vi are usable editors could
think this was an appealing virtualisation solution.

Did I mention my more or less complete and utter loathing for C21 computing?

Why do you think I'm playing with MS-DOS again after 20y?

-- 
Liam Proven • Profile: https://about.me/liamproven
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