diskless DOS client

[T. Ment]

On Sat, 30 May 2020 19:04:57 +0800, Johann 'Myrkraverk' Oskarsson wrote:

> I'm still looking for a place that sells refurbished machines locally

For a diskless client PC, all you need is a motherboard, cheap Realtek
8139 NIC, power supply, and case.


> what people are currently using, and what hardware is available can be
> extremely helpful.

I always wanted a diskless DOS client and I finally got around to it.

You can do it with PXE but the ROM takes about 40k of upper DOS memory,
I wanted something smaller, so I went with RPL, the old way, back in the
DOS days. It's hard to find a motherboard with a NIC ROM that old, most
are PXE now.

But Realtek still has an 8139 RPL ROM for download. I burned it to a 32k
ROM chip, put it the NIC socket, activated the ROM size on the card with
the Realtek setup utility, and booted it up. It only takes 14k upper DOS
memory, much better.

The RPL boot ROM talks to a Personal Netware server running on DR-DOS
7.03 and loads a bare bones DOS image over the network. Once connected
to the server, you can load more files and do whatever you want.

It took a lot of trial and error to get it working, this old stuff is
not well documented. Documenting what I did would take days.

That's too much work, since no one else is likely to care, But if anyone
has specific questions, I will try to answer.

[Johann 'Myrkraverk' Oskarsson]

On 31/05/2020 2:15 am, T. Ment wrote:
> On Sat, 30 May 2020 19:04:57 +0800, Johann 'Myrkraverk' Oskarsson wrote:
>
>> I'm still looking for a place that sells refurbished machines locally
>
> For a diskless client PC, all you need is a motherboard, cheap Realtek
> 8139 NIC, power supply, and case.

That might work, thanks.

>> what people are currently using, and what hardware is available can be
>> extremely helpful.
>
> I always wanted a diskless DOS client and I finally got around to it.
>
> You can do it with PXE but the ROM takes about 40k of upper DOS memory,
> I wanted something smaller, so I went with RPL, the old way, back in the
> DOS days. It's hard to find a motherboard with a NIC ROM that old, most
> are PXE now.
>
> But Realtek still has an 8139 RPL ROM for download. I burned it to a 32k
> ROM chip, put it the NIC socket, activated the ROM size on the card with
> the Realtek setup utility, and booted it up. It only takes 14k upper DOS
> memory, much better.
>
> The RPL boot ROM talks to a Personal Netware server running on DR-DOS
> 7.03 and loads a bare bones DOS image over the network. Once connected
> to the server, you can load more files and do whatever you want.
>
> It took a lot of trial and error to get it working, this old stuff is
> not well documented. Documenting what I did would take days.
>
> That's too much work, since no one else is likely to care, But if anyone
> has specific questions, I will try to answer.

I'm still uncertain about what hardware/software combinations I'll go
with, but this sounds tempting. Since I'm unsure right now, I have no
questions for the time being.


--
Johann | email: invalid -> com | www.myrkraverk.com/blog/
I'm not from the Internet, I just work there. | twitter: @myrkraverk

[T. Ment]

On Sun, 31 May 2020 05:29:28 +0800, Johann 'Myrkraverk' Oskarsson wrote:

> I'm still uncertain about what hardware/software combinations I'll go
> with, but this sounds tempting. Since I'm unsure right now, I have no
> questions for the time being.

Sometimes I don't even use a case. Just a motherboard and power supply
with something plastic under it to prevent unintentional grounding. You
don't need much space for that.

But you need to know and practice electrical safety. Otherwise, it's not
recommended.

[T. Ment]

On Sat, 30 May 2020 18:15:39 +0000, T. Ment wrote:

> Realtek still has an 8139 RPL ROM for download.

VIA Rhine LAN adapters are common on old motherboards. VIA download
still an RPL ROM for them, named RPL.LOM (Lan On Motherboard).

Since it's on the motherboard, the ROM is embedded within the system
BIOS, and you have to fiddle with that. Not too hard with Award BIOS,
you can find a BIOS module editor named CBROM.

I tried it on a motherboard I could afford to lose. I removed the PXE
ROM module, replaced it with RPL.LOM, flashed the BIOS, and rebooted. It
worked.

Beware though, if your BIOS chip is soldered on, it's risky.

But even a bricked BIOS is not hopeless. With the right tools and skills
you can desolder it, solder a socket in its place, burn a good BIOS into
the chip with a universal programmer, insert the chip in the socket, and
there you go.

It tedious and delicate though. I've killed boards with too much heat
while desoldering. They factory uses lead free solder, which is harder
to work with because it requires higher temperatures. Not a problem at
the factory, but it makes field repair difficult.

Flux helps. Don't skip the flux to avoid the sticky mess.