recursive emulation

On 25 January 2017 at 00:19, Jecel Assumpcao Jr. <jecel at merlintec.com> wrote: The Risc PC had a 2nd processor slot. It wasn't able to be a full SMP machine, but there were options for a 2nd ARM chip (which would have to be custom programmed), a 3rd party multiprocessor board: http://chrisacorns.computinghistory.org.uk/32bit_UpgradesH2Z/Simtec_Hydra.h… ... Or Acorn's own official "PC card". http://www.retro-kit.co.uk/page.cfm/content/5x86-Risc-PC-PC-Card/ I actually have 2 or 3 of these, boxed, awaiting restoration of my RiscPC. The card didn't do much for RISC OS, but allowed a native-CPU-speed PC emulator app. The card had a real processor, but used software-emulated I/O -- disks, screen, sound etc. -- so it wasn't very compatible. It would run MS-DOS, Windows 3 and 95. Win98 very slowly with significant caveats. Win95 ran in a minimally acceptable mode, using "MS-DOS disk and file access" -- in other words, dropping to BIOS calls, as there was no real disk or screen hardware for its VxDs to address and control. There is/was a commercial app to use the PC Card's onboard FPU to accelerate RISC OS FP operations: http://www.wss.co.uk/products.html#FPEPC This is only faster on ARM6/ARM7 RiscPCs, though. StrongARM machines could do faster FP in software. -- Liam Proven ? Profile: https://about.me/liamproven Email: lproven at cix.co.uk ? Google Mail/Talk/Plus: lproven at gmail.com Twitter/Facebook/Flickr: lproven ? Skype/LinkedIn/AIM/Yahoo: liamproven UK: +44 7939-087884 ? ?R/WhatsApp/Telegram/Signal: +420 702 829 053