Deja News Toolbar NECX: #1 for Computer Hardware Get It Now: NECX [Today's Best Buys] GO message/thread Message 301 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: : 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? The version discussed in edition 1 of the OS:D&I was AFAIK 1.0, possibly 1.1. 1.2 had a kernel around 110K, 1.3 around 125K, 1.4 didn't exist, 1.5 around 140K. 1.6 was probably similar to 1.5, and 1.7 to the current 2.0, around 190K. 2.0 is discussed in the current edition 2 of OS:D&I, and the current release version is 2.0.2. (Don't quote me on any of those numbers, which are from my failing memory. They assume minimal kernel buffers, and no networking). You do _not_ want to deal with any version of Minix early than 1.3, or preferably 1.5. You also don't want to run any version of Minix in less than 512K of RAM. : > : 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. I've written a lot of code under Minix, and considered doing a port to the PowerPC; I dropped it for reasons unconnected with Minix, but I put the effort at 50-100 mandays, depending on how much time had to be spent porting a compiler, and how much functionality was needed. The networking code, for instance, is pretty obscure and I didn't include it in the porting work. : > 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 may be thinking of Amoeba, which is a distributed OS using a microkernel, and for which ast was the lead architect. It's very different to Minix. [...] : > 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. Well, to be honest, in a project of this size you shouldn't be writing too much assembler; you haven't got the time. As a rough check, the mm, fs, and kernel directories of Minix 2.0.2 contain 25,000 lines of C code and 2000 lines of assembler; the assembler functions being needed mainly to handle i/o ports, interrupts, and fast data moves. UZI will have much less - I wouldn't worry too much about the processor differences if I were you. 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