Haven't really moved on much further at the moment but the files posted by Andrew look interesting, thanks.
I've discovered that the reason the Nexus cards don't work on RISC OS 4 is possibly because of the ROS4 custom !Boot structure.
Pre RiscPC machines boot directly from the Nexus once configured correctly. On a RiscPC the Nexus software needs to be booted the first time holding down the 'X' key on the RiscPC when it starts up. It should then alter the universal boot. I think this allows it to load items from the Nexus during the boot process but leaving the RiscPC universal !Boot as the primary. I haven't worked out what it alters yet, if I can do that then maybe I can get it to work with the ROS 4 !Boot structure, including softloading 4.39. Haven't looked at RISC OS 6 yet.
Anyone know of a utility that compares !Boot structures? ie, so I can compare before and after to see exactly what files it alters/adds?
I believe SJ Research product support was eventually taken over by Cumana, possibly Explan for a bit and then finally Design IT.
I'm guessing Rob Cowell may have newer SJ Research related disc releases and source code as proprietor of Design IT. A couple of the RiscPC Nexus cards have Design IT labels with version 2.24 printed on them but I have no release discs that mention Design IT. I contacted Rob a couple of times over the past year or so and he seemed able to help with binaries/documents, he believed he had them on his personal MDFS that he'd have to dig out but he never got back to me and I didn't want to annoy him any further. Perhaps if he sells his Acorn kit we'll get hold of the Nexus/SJ Research stuff.
Nexus Card ROM versions
Version 2.22 doesn't have any markings, I'll try plugging it in to my RiscPC and see if there's any clues.
Version 2.23 possibly the Cumana version, but not confirmed that yet.
Version 2.24 SJ, Design IT markings on ROM.
I've discovered that the reason the Nexus cards don't work on RISC OS 4 is possibly because of the ROS4 custom !Boot structure.
Pre RiscPC machines boot directly from the Nexus once configured correctly. On a RiscPC the Nexus software needs to be booted the first time holding down the 'X' key on the RiscPC when it starts up. It should then alter the universal boot. I think this allows it to load items from the Nexus during the boot process but leaving the RiscPC universal !Boot as the primary. I haven't worked out what it alters yet, if I can do that then maybe I can get it to work with the ROS 4 !Boot structure, including softloading 4.39. Haven't looked at RISC OS 6 yet.
Anyone know of a utility that compares !Boot structures? ie, so I can compare before and after to see exactly what files it alters/adds?
I believe SJ Research product support was eventually taken over by Cumana, possibly Explan for a bit and then finally Design IT.
I'm guessing Rob Cowell may have newer SJ Research related disc releases and source code as proprietor of Design IT. A couple of the RiscPC Nexus cards have Design IT labels with version 2.24 printed on them but I have no release discs that mention Design IT. I contacted Rob a couple of times over the past year or so and he seemed able to help with binaries/documents, he believed he had them on his personal MDFS that he'd have to dig out but he never got back to me and I didn't want to annoy him any further. Perhaps if he sells his Acorn kit we'll get hold of the Nexus/SJ Research stuff.
Nexus Card ROM versions
Version 2.22 doesn't have any markings, I'll try plugging it in to my RiscPC and see if there's any clues.
Version 2.23 possibly the Cumana version, but not confirmed that yet.
Version 2.24 SJ, Design IT markings on ROM.
Statistics: Posted by Alanex — Mon Jan 22, 2024 11:48 pm