Building an ARCNET (also Pure Data PDI 508+)

20Oct/250

Building an ARCNET (also Pure Data PDI 508+)

No, not an ARPANET, an ARCNET. I was recently given a box'o'junk from a friend who was cleaning up a telco engineers house and, honestly, had no idea what I was look at!

Turns out that it's a box full of ARCNET cards and some patch panels. Tiny 8-bit cards, longer 8-bit cards, huge 8-bit cards and even some 16-bit cards! A lot of them are Pure Data branded. Another name I'd never heard of... I did see a bit of SMC though!

I then went down a rabbit-hole of research... with everything seeming to indicate that these cards will simply work as the physical layer to whichever protocol you wish to run on top... so... let's try it!?

The Machines

First up we have a Toshiba T3200 286 Laptop. This thing has an 8-bit and 16-bit ISA slot in the rear, and the usual IEC-13 power plug. Quite the beast. Although it's old and tired, it'll work nicely with Microsoft LAN Manager. Turns out the drivers are already there!

Next up is a 486 DX4/100 and a P2-350. These are the usual desktop workhorses for writing floppies and testing old hardware. They've been sleeping for a while and are quite buried... so it'll be a bit of work to spin them up and test things.

SMC ARCNET PC270E

I chose this card as the first test article. There's a few in the box and they have the least dipswitches of all cards (that have dipswitches) that aren't PNP?. Turns out there's also a one-size-fits-all driver for this card and it's included in all systems I tried.

2. PC130 (SMC 8-bit driver): Newer 8-bit SMC boards with SMC90C63 controller
   chips use the PC130 family workstation driver. RXNET and TRXNET drivers
   can also be used. Boards in this group include the PC120, PC130, PC130E,
   PC220, PC260, and PC270E. The PC130 driver is a workstation only driver.
   If you wish to one of these boards in the server please use the RXNET
   or TRXNET drivers.

Being dipswitch-based, the jumper settings can be found here. Note that 0 is ON and 1 is OFF. That really confused me and I kept configuring the switches in the reverse order; wondering why nothing was working.

With a card in each of the machines, I started hooking up the cabling was exactly the same as an Apple LocalTalk network. RJ11 cables between nodes (any port on the cards) and terminating resistors at the far ends.

After setting some static IPs, I could ping from PC to PC! Unfortunately, the MSLANMAN 2.x installation on the 286 wouldn't ping in either direction.

SMC ARCNET PC260

This card works with the stock drivers but, with the driver installed, Windows 95 started to actually lag. Window and control re-draw rates slow right down, but the card still works. I can only really recommend using these in DOS or lower?

Although I did also try with Windows 98 and it worked fine... so it may have just been an incompatibility with the DX4/100 motherboard and/or resource settings.

PUREDATA PDI507

This seems to be very similar to the SMC above. It also includes BNC for when you don't feel like stringing RJ11 around the house.

PUREDATA PDI508+

This was a can'o'worms. I couldn't get a response from the card in any machine I tried. Windows has the drivers for these cards by default, but they always just showed up as driver failed to load.

There are hardly any settings, as it seems this is a very early PNP card!? Amazing... but frustrating as this EISA configuration document indicates that we need a custom configuration app to configure the settings:

Select desired Network Operating System or General Use to obtain valid hardware configuration options.
PDI508 ArcNet provides a configuration file CFGI508.EXE that will set all memory, I/O, and interrupts (also set through jumper JP2).

Oh great... well... I'm sure this blog will become the first (and only) hit for CFGI508.EXE on the web... as it's lost to time. Or is it? Turns out there's currently an auction for a 5 1/2" disk with, I assume, that exact configuraton app on it... but it's exorbitant. Then again, it's not like I haven't scoured auctions to find configuration apps before.

What is hilarious though, is that this auction has photos of the manual... and I stole them:

Hah.. look at that... default settings! Of course, it's the exact default of the earlier PureData/SMC cards.

Option	Default value
Memory Address	0xD000
I/O Base Address	0x2E0
IRQ	2
Node Address	0xF0 or 0xF1?
Response Time	74us

But how, you may ask, do we get the default settings to apply? Turns out there's a jumper on the card to clear the settings! stason.org to the rescue with the board layout! I assume it's a bridge-jumper and boot to clear... then power off, remove bridge, power up and go.

And well, it just worked with the default settings. Perfectly! But, you know what? I want the software... so I bought it...

and...

Yey! The files! I backed it up straight away. The configuration app works in the laptop... but not on the Windows 98 Dos Prompt. Either way, I can re-configure cards now!