a577@mindlink.UUCP (Curt Sampson) (04/07/90)
> karn@jupiter..bellcore.com writes: > > Yes, my code did indeed begin life on CP/M, specifically the Xerox 820. > But this was five years ago, and much has happened in the meantime to PC > clone pricing and availability to make me wonder why anybody would still > be interested in CP/M. With XT clone boards having bottomed out at $60 > or so, and with a well-established and highly competitive supplier network > supporting PC technology, why bother with Z-80s and CP/M? I just don't see > the point. There are several reasons. One is cost. I bought a Kaypro 4 for $200, which is the price of two double sided drives up here. (Buy two drives, get computer thrown in free! What a deal!) To get an equivalant IBM system would have cost me about $500-$600 for the hardware and probably another couple hundred for the software. A good electronic type writer costs as much as my whole system (it cost me another $85 for the printer). Another reason is speed. My Kaypro runs faster for non-number crunching tasks than an 8 MHz XT with floppy drives (and in some cases, even a hard drive system). There's no way that a machine can load a 200K program faster than a machine can load a 25K program. And because the CP/M machine is doing a lot less, even with less processing power it is often faster. I get by fine without a lot of the extras that the IBM programs do. (I have no particular need for windows.) The last reason is that it's fun! CP/M machines are simple enough that you can play around and hack with the OS without any major problems. If this is what makes someone happy, then that's what they should be doing, no matter how cheap XT motherboards are. I'm not trying to start any kind of a "my computer is better than yours" war here, just trying to point out why I prefer my CP/M machine to my IBM XT clone. (I just bought the XT clone to run a BBS.) Feel free to flame me though--just send it to net.comp.amiga. :-) -CJS ( Curt_Sampson@mindlink.UUCP )
cs2591aq@carina.unm.edu (aNk1ez) (04/09/90)
No kidding! I have come across TWO S100 CP/M machines, both with nice hardware (HDU, consoles, etc) for FREE. when you realize the raw power that a z80 has you can see why many of us "who are stuck in the past" LIKE the Z80! according to a test done by a friend of mine (also reachable through this common account; email to Dent / cs2591aq@carina.unm.edu) the Z80a at 4MHz does a MIP. far as I can tell, the IBM XT doesn't even come close to a MIP. Back to my topic tho... the BIG Z80B machine @ 6MHz runs considerably faster than a 286 /16MHz machine.. when you throw in the 80mb hard drive and a hacked up copy of Uzi (very nice) this machine does more than i could ever want in a personal computer. ( for any one thats ever used ariel.unm.edu, this machine is comparable. (not it power, but in time that it responds to user requests. )) anyways... Techs / cs2591aq@carina.unm.edu aNk1e ByT0rz common account
jensting@skinfaxe.diku.dk (Jens Tingleff) (04/09/90)
While on the subject of cheap systems, I bought a CP/M-68k system (8MHz 68000, 0.5 MB, 2x1MB drives, .....) for appr. $400. The original list price was some $8000 (yes, 20 times as much), back in the dark ages (spring -85). Of course, until the C compiler appeared in comp.os.minix, I had practically given up on using it due to the nature of the Alcyon CC. The reason for the cheapness was CP/M, meaning NO software avaiable (the only software I found was an Modula-2 compiler, at the same price as a single-user license for a SUN...). Today, I couldn't even sell it without loosing money. Some day I'll overcome my nostalgia, and sell it as scrap. SIGH. Jens jensting@diku.dk is Jens Tingleff MSc EE, Research Assistent at DIKU Institute of Computer Science, Copenhagen University Snail mail: DIKU Universitetsparken 1 DK2100 KBH O
madd@world.std.com (jim frost) (04/10/90)
cs2591aq@carina.unm.edu (aNk1ez) writes: >far as I can tell, the IBM XT doesn't even come close to a MIP. About .4 mips at 4.77MHz with an 8086 (although you realize that "mips" is pretty meaningless). jim frost saber software jimf@saber.com
dg@pallio.UUCP (David Goodenough) (04/10/90)
A couple of points: > According > to a test done by a friend of mine (also reachable through this common > account; email to Dent / cs2591aq@carina.unm.edu) the Z80a at 4MHz does > a MIP. Only assuming it's executing single byte instructions. Something like ld a,(0x1234) takes 13 T states, so those done repeatedly would only achieve 1/3 MIP. On average, I'd guess it'd hit about 1/2 MIP doing _REAL_ work, although some instructions ('inc (ix + dd)' or 'call xxxx') really hog CPU T states. On the other side though, it still chugs along nicely: a 4MHz Z80 can do the CRC and data transfer to keep an Xmodem transfer going at up to about 22000 BPS, and that's doing the CRC the hard way (i.e. bit banging), with a table driven CRC, it'd probably exceed 38400 BPS. Now, why do _I_ bother with CP/M: One reason is that you gotta keep it small: 57K of TPA can vanish in a real hurry. Keeping it small usually means keeping it simple, and simple programs are easier to write and maintain. -- dg@pallio.UUCP - David Goodenough +---+ IHS | +-+-+ ..... !harvard!xait!pallio!dg +-+-+ | AKA: dg%pallio.uucp@xait.xerox.com +---+
gpz@bridge2.ESD.3Com.COM (G. Paul Ziemba) (04/11/90)
dg@pallio.UUCP (David Goodenough) writes: [somebody else writes:] >> a MIP. >1/3 MIP. >1/2 MIP Aaaaaarrrgggghhh! If I may nit-pick for just a moment... MIPS = Million Instructions Per Second. MIP = ??? Ahh. There, I feel better now :-) :-) ~!paul -- Paul Ziemba zapi!gpz gpz@3com.com (415)940-7671 Current nemesis: CA "winters", cold enough to drive the ants indoors but not cold enough to make them hibernate.
cs2591aq@carina.unm.edu (aNk1ez) (04/12/90)
>[somebody else writes:] >>> a MIP. > >>1/3 MIP. >>1/2 MIP > >Aaaaaarrrgggghhh! If I may nit-pick for just a moment... >MIPS = Million Instructions Per Second. MIP = ??? Arrgh! MIP, MIPS.,. its all the same thing... you knew what we were talking about.. why gripe? MIPS - Million INteractions Per Second. I know that. it sounds rather silly to say 1 MIPS, 1/2 MIPS, 1/3 MIPS. So, we've all just depluralized the acronym... makes PERFECT sense to me.... :-) Techs / cs2591aq@carina.unm.edu aNk1e ByT0rz k1Ub common account this disclaimer space intentionally left blank.
compata@cup.portal.com (David H Close) (04/12/90)
dg@pallio.UUCP (David Goodenough) writes:
" On the other side though, it still chugs along nicely: a 4MHz Z80 can
" do the CRC and data transfer to keep an Xmodem transfer going at up to
" about 22000 BPS, and that's doing the CRC the hard way (i.e. bit banging),
" with a table driven CRC, it'd probably exceed 38400 BPS.
Actually, it will do even better. I know of a 4MHz Z80 pumping 56Kbps SDLC.
Dave Close, Compata, Arlington, Texas
compata@cup.portal.com OR compata@mcimail.comkleinj@jacobs.CS.ORST.EDU (Justin the Blue) (04/14/90)
Why bother with CP/M? It's not much of an answer, but more of a preface: my very first computer was a Xerox 820/I, the single-board wonder. The guy who put it all together used old steel Tektronix cases as chassis. They are indestructible, and give one the added advantage of having an extra seat around for a guest. "Can't find a seat!" "Go ahead...sit there." "But, that's the computer!" Seriously though, We here at SunDial use two computers. One is an IBM PCI, which we lucked into...the salesman was under the impression that the drives were Single Side Single Dense, and only 128Kb memory, and when we got home with it ti turned oout those drives were DSDD, and 256Kb memory...for $250, and IBM original. I have been exploring the PCDOS 3.3 world as a child with the bestest new toy in the universe. I really like it...features like sub- directories allowing me to organize files to my liking, and compatibility with all the shareware I could ever want. Sure couldn't do that with CP/M. But what I can do with CP/M is: the same basic stuff, simply, quickly, and well. So your computer is a '386 that runs at 32 Meg with so much storage I could move a Cambodian family in. Last time I looked at my applications, I just plain didn't need such conspicuous consumption. So, I like the IBM world, more so that I now can tak a part in it. But don't tell me that CP/M is: Outmoded Difficult Too Simple, Or, that favourite stupid comment that I mostly hear snooty Clone and Macintosh users spout.... Isn't that an OBSOLETE OS? NO, no more than breathing air an obsolete way of getting respiration. (next time a snooty IBM/Clone/Mac user starts getting your goat, remind them of a great advantage of 'obsolecence'.... When was the last time you heard a CP/M user all upset about Whether or not a virus was getting at their system. They shut up real quick after you remind them of this.) -Justin the Blue-