Nov 152017

A couple of years ago, RISC OS Open Ltd started building versions of RISC OS with “zero page relocation” – with the memory map changed such that the kernel’s workspace that started at the bottom of the addressable memory was moved to a higher location. This was an important step for security and stability, and for the future of the operating system.

However, it wasn’t ever going to happen without some casualties along the way; software that in some way tried to use or access certain information held in that workspace and which therefore found it no longer available. Aemulor, the 26-bit emulator that allows applications that are not yet fully 32-bit run on newer hardware, was one such casualty – and an important one at that. Continue reading »

May 192013

Wave, Gen, you’re on RISCOSitory!

A couple of old applications for generating RISC OS sounds have been updated for 32-bit compatibility by Jon Scott.

The first of these, announced by Jon on the RISC OS Open forums as a re-release of a very old voice module generator, is Wavegen, an application that can create perodic sounds based on mathematical formula such as a simple sine or complex harmonic wavforms. Continue reading »

May 192013

No, just because it’s on the internet and it’s called Cat_Draw, that doesn’t mean there are cute pictures of cats.

Long time RISC OS user Martin Carradus popped up on the RISC OS Open forums in February in response to a comment about his application, Cat_Draw, not being 32-bit compatible. Martin initially offered to supply his source code, presumably to allow someone else to make the application 32-bit compatible, but a couple of hours later posted again to say that he had now recompiled it himself. Continue reading »

Apr 072013

Sound as a 32-bit compatible pound.

There are a number of ways to make RISC OS computer play sound samples – perhaps for sound effects in games – and one of these is to turn the sound sample into a voice module, an option often provided by software that works with audio samples. One such example was Armadeus, which came from Clares Micro Supplies – and is the software I used myself for the sound samples used in some of the budget games released by Soft Rock Software in the late 1980s and early 1990s. Continue reading »

Sep 082012

Make your 32-bit computer do an Impression (ho-ho) of a 26-bit one!

When Castle Technology Ltd launched the IYONIX pc, back in 2002, there was a significant question users needed an answer to before upgrading to the new computer: Would their old software run on the new hardware?

The problem was that for all the previous RISC OS computers, the ARM CPUs worked in (or supported in the case of StrongARM) an addressing mode we refer to as ’26-bit’, in which the program counter and processor status flags are contained in a single register; six bits are used for the status flags, and 26 bits for the program counter – the pointer to where in memory instructions are read for execution. With instructions always being word-aligned, rather than byte-aligned, the 26-bit program counter actually provides a 28-bit address range, representing bits 2 to 27 in the actual address – the lower two bits pointing to the instruction to be read are always zero. Continue reading »