Yes, I did this with an SX52 board.

It was surprisingly easy. I'd been worried about satisfying the refresh requirements, but as I was using RTCC-controlled interrupts anyway for RS232 communication, I was able to just stick a refresh command into the ISR and it worked like a champ.

Here's some code. I was developing a bike speedometer/heartbeat sensor at the time, so you'll see lots of semi-developed code for those things. But the dynamic RAM and the RS232 ISR parts were working perfectly.

David

David,

   Yes I should've mentioned using interrupts to maintain refresh.  That's how it was done with the Z80 back when I studied that myself.  I didn't think anyone had really messed around with it on an SX though.  Refreshing to see something new and thought to be too difficult to bother with.  Nice work.

David,

   I remember doing a college project on the refresh for Z80, but not on a PC Memory Module, instead using 8 DRAM chips which were 1K X 8.  In any event when I started making my own boards I used SRAM.  More expensive, but a lot less complex and you could even get a Dallas version with battery backup.  But I do remember the DRAM Refresh thing.  You are bringing back memories of details I forgot.  I had thought we used an interrupt to handle it, but now that you mention it...In my own boards NMI was used for the watchdog and the IRQ line was used to update an RTC.  Amazing how many chips I went from down to a BASIC Stamp Module and a few misc chips.  Anyway thanks for providing all that information.  The more ambitious SX'ers will be able to turn that into some cheap mass storage.