The Sinclair QL Forum

QL with a very unusual expansion board on Ebay
I presume this is some custom industrial expansion board - Does anyone knows what this might be?

My guess would be stepper motor controller and driver...

The screen shot says it's an engineering company.

Could it be a IEEE interface for driving things like milling machines.

I asked my son, as he works with modern engineering machining systems. Not being a QLer, he couldn't identify it specifically, but agrees with comments made about what it might be. He says that there is still a company called Hurn Brothers (engineering) Ltd in Dereham, Norfolk UK, although that might be a coincidence of names.

CST made a SCSI interface for QL back in the 1980s, though this doesn't look like the pictures I've seen of those.

A SCSI interface would commonly have a 50 pin connector.

Hope whoever won this auction on eBay is on here and can give us the lowdown on what it was!

Would be worth contacting the engineering company to see if they have the software still (or even any QLs still in use!)

Andrew wrote: Mon Jun 24, 2024 9:54 amI presume this is some custom industrial expansion board - Does anyone knows what this might be?

Probably servo motor control as steppers were not so prevalent back then when CNC were coming in.
https://united-kingdom.exportersindia.com/stebon-ltd/
https://www.daxautomation.co.uk/part/pa ... d40/338615

I think the question is mainly about the QL expansion board.

Without the two obviously missing chips, what remains is the EPROM and a bit of address decoding, and it's nearly impossible to tell what might have been in the two empty sockets. But they somehow yell "UART" at me. In the mid-1980s, serial comms was ubiquitous in controlling machinery. From the pin count, the missing chips could very well be Intel 8251 UART chips.