To follow up on this with what I’ve learned: As expected, lots of places online will say they have a thing on their web site, and then when you ask for a quote they won’t actually have it.
However, ServerWorlds not only had HP 98229-66524 16MB memory modules listed, they also had a price and in-stock quantity listed! So I ordered a couple to try. https://www.serverworlds.com/hp-98229-66524-16mb-simm/ They have a whole lot fewer now, because it turns out that despite what it says in the HP-Apollo 9000/400 Series Owner’s Guide, the 425t *does* support 16MB modules! My system comes right up, all self tests pass and it says it has 32MB of memory with two modules. So I’ve ordered six more to get to 128MB. In the worst case, I figure it’ll only allow me to put half that in, and I can pass the memory along to someone else who buys a 9000/375, 380, or 400 series with no RAM. All that said I’m quite surprised MAME doesn’t include HP-Apollo 9000/400 series emulation. The hardware is very similar to the 9000/380, which is supported, and several Apollo DN series systems are also supported… Hopefully I can install Domain/OS on a virtual disk using MAME (using the same node ID) and just blast the raw bits to a SCSI disk to make something bootable. Anyone know whether that wouldn’t work? — Chris
