Deja News Toolbar BuyDirect BuyDirect message/thread Message 237 of 305 for search * return to search results help Re: Porting Minix to the SuperCPU Author: Will Rose Date: 1999/02/12 Forum: comp.os.minix more headers author posting history post reply prev next _________________________________________________________________ Patrick/RPG (cr@interlog.com) wrote: : Here's a question for all of you hardware hackers and OS programmers! : Which processor was Minix originally designed for? From older postings, : I've received the impression that the original versions of Minix were : written for a 16-bit architecture. It was intended for a _standard_ IBM PC with two floppy drives and 256K of RAM. However, it's got fat over the years and even 1.5 wasn't really happy without 10-20MB of hard drive. : Now, how hard do you all think it would be to write a port of Minix for : the SuperCPU accelerator board for the C128? Reasonably hard. : For those of you who don't know, the SCPU is a plug in board for the : Commodore 64 and Commodore 128 computers. The board offers 20 MHz : processing speeds on a W65C816S 16-bit processor, which has an x502 : 8-bit processor emulation mode. : However, is it possible to run the SCPU in stock 16-bit mode, and still : use available stock-Commodore I/O, ie: Disc Drives and Video? El Cheapo : Assembler would seem to indicate so, as it is a 16-bit assembler, no? : Add to this that the C128 already has facilities for accessing 256K of : RAM, and there are modifications for 1024K of RAM _inside_ the C128 : (with it's internal MMU), and the SCPU can have 16MB of it's OWN : internal RAM, and you have the potential for 17MB of RAM. On top, add : in a 1750XL REU, and you have 19MB total RAM. Minix doesn't need a lot of RAM; it can run on an XT with 640K, tho' it's better off in 2MB. : Video would be a problem of course, but the C128 VDC chip already : supports a nice 640*400 interlaced format for graphics, which should be : more than enough graphics power for a text-based OS such as Minix. : Also, it is my understanding that Minix is a micro-kernal OS, meaning it : runs on top of the host OS's Kernal. All we would have to do is : interface the entire thing with the C128 Kernal. Better yet, interface : it with ANOTHER microkernal such as ECOS or ACE on the C128, or ACE or : LUnix for the C64! And you have a very powerful OS! No, Minix runs on the bare silicon (apart from the Mac version). It's not a micro-kernel by any stretch of the imagination; it's a simple and pretty modular message-passing kernel. You'd need a cross-compiler, probably, on your development system; and then you'd need to write the drivers for floppies, video, keyboard and clock at least; preferably for the hard drive. I don't think it would be worth the effort, on the whole. Have you looked at the current version of UZI (ask in comp.os.cpm)? That's a lot smaller, designed for the Z80, and might be a simpler port. Will cwr@crash.cts.com _________________________________________________________________ view for bookmarking text only mail this message to a friend post reply << prev · next >> subscribe to comp.os.minix SPONSORED LINKS Yellow Pages · Save$$ at uBid · Express by Infoseek · Shopping · Free Stuff AutoConnect · Trade with Datek · Auctions & Classifieds · GET IT NOW @ NECX Home · Communities · My Deja News · Power Search · Post About Deja News · Ad Info · Our Advertisers · Deja News Store ____________________________________________________ Copyright © 1995-99 Deja News, Inc. All rights reserved. Conditions of use · Site privacy statement reviewed by TRUSTe