More expansion cards join RISC OS 5
Posted by Steve Revill Fri, 11 Oct 2013 14:27:00 GMT
Background
Since the first fully 32 bit RISC OS appeared over a decade ago a relatively small proportion of expansion cards have been updated compared with the number of general purpose applications that have been.
This need not be the case – the platforms running RISC OS 5 which have an expansion bus inside (Iyonix PC; Risc PC; A7000; and A7000+) are all electrically unchanged when the processor talking to them is in 32 bit mode, so a podule which works on the Iyonix PC can just as easily plug into an A7000.
It’s just the software that needs attention.
The process of updating an expansion card driver is fairly formulaic, and by using official operating system calls the result is still backwards compatible with earlier versions of RISC OS. This makes maintaining the driver a lot easier as there’s only one version to keep track of!
The main steps in the conversion are:
- any modules need to be made 32 bit compatible either by recompiling the source code (or hand modifying if written in assembler)
- if a loader is used (pre-Risc PC era IOC or MEMC podules only) this will need to be made 32 bit compatible too, and marked with the signature word “32OK” at offset 16 of the loader’s header
- make sure all hardware addresses are requested from Podule Manager using the Podule_ReadInfo SWI as the address of the I/O controller should not be assumed to be down at 0×32000000 where it was on the Archimedes computer
- if support for pre RISC OS 3.50 (when Podule_ReadInfo was introduced) is required, then it is safe to assume the original Archimedes memory map if the Podule_ReadInfo SWI is not found
Following these guidelines, RISC OS Open Ltd are pleased to announce the immediate availability of two expansion card driver updates. The first is an updated Ethernet driver (“EtherY”) for the Castle 10/100 network interface, and the other is an updated set of SCSI drivers for the Acorn SCSI podule.
The SCSI podule is a good example of how updating just one expansion card unlocks large chunks of other functionality with relative ease: it includes the latest SCSI filing system and CD-ROM drivers as featured on the Raspberry Pi.
Summary
Neither of the companies that produced the hardware are still active in the area, but it is still possible to produce updates. Developers can feast on the large number of expansion cards available that can be ‘adopted’ and brought back to life. Alternatively, why not contact the vendor of your expansion card and ask when they’ll be updating it?
Availability
The EtherY driver can be downloaded by clicking on the “NICDrivers.zip” link on our downloads page. The ZIP includes an update to apply to the !Boot sequence for disc based loading, or the driver can be put into flash memory on the expansion card itself.
The SCSI drivers are available on ROM chips from the ROOL store. The update is easily installed by following the provided fitting instructions, requiring a small flat head screwdriver.
