Deja News Toolbar Complimentary Resources for Developers. Complimentary Resources for Developers. message/thread Message 278 of 305 for search * return to search results help Re: Porting Minix to the SuperCPU Author: Patrick/RPG Date: 1999/02/12 Forum: comp.os.minix more headers author posting history post reply prev next _________________________________________________________________ Will Rose wrote: > 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. No big deal. RAMLink's go up to 16MB, and most users now have a CMD-HD kicking around. Even if not, the are readily available from CMD. If you ever move to another system, take the CMD with you, it is an investment in the future. :) And if it was designed for 256K of RAM, then the C128 is perfect. Also, fat? Hm. Well, stick with the basics then, and customize as required. When you say fat over the years, are you referring to the original version with the book, or the "public" version that is available on the 'net? > : 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. Elaborate. Other than the drivers, which I have explained below. > 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. No, I could have sworn that I had read somewhere that Minix was a micro-kernal. I believe I read this in the MacMinix FAQ, or somewhere similar. > 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. Cross compilers are available. Writing the disc drivers isn't as hard as it would seem. At first glance, you could simply copy the standard CBM ROM routiens. Many ppl have also already rewritten their own routines for disc I/O. If you restrict the OS to the C128, every 1571 and 1581 manual comes w/ routines for the BCIS, which is initself the disc driver. Of course, you you have to write the BDOS for the drive itself. However, since CMD devices have natural sub-directories, let the HD take care of all of the grunt work, IE: making diretories and such. Keyboard routines? Look at ACE. Craig Bruce has already written them. Same goes for Video. Writing screen drivers is _NOT_ as hard as it would seem. The fastest way is to use a simple lookup table, calculate the memory position on the screen, and POKE the value directly to video-RAM. Keyboard drivers? As I said, CSB has written them. Although his article in C=Hacking jumps to the standard CBM kernal for decoding the values (I *believe* he does this), it isn't hard to write your own. I already have, and can post the source if anybody is interested. [Note: the routine is huge, as it uses look-up tables right now.., and is a variant on CSB's routines..]. > 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. I've been looking at Z80 code, as I had considered this already. NOt for UZI, but for porting other Z80 programs to x502. However, the instruction set's for both processors (at first glance) seem hardly compatbile. IE: Z80 has facilities for 16-bit operations, relative jumps and the like. The only relative commands that the x502 have are branch instructions, and there are no 16-bit operations. Although you could hack it together with software. -- Cyberad/RPG aka Patrick M Pritchard * http://www.interlog.com/~cr PLUR- Peace Love Unity Respect -Live It, Love It, Be It, BELIEVE! RENEGADE PROGRAMMING GROUP IN 1999 -- Taking It To The Next Level _________________________________________________________________ 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