Maybe we're talking about two different things, Sam. I thought we were
going to put forth a specification for participants to code for whichever
processor they wanted or both, just to see which one came out fastest,
smallest, or whatever...est.
You were the one who mentioned the graphics so one could see what was going
on. What I had in mind was a computation, e.g "compute the product of three
M x N x L matrices, where M, N, and L are <127, containing prime decimal
numbers of not more than 511 and not fewer than 256 digits each".
An environment has to be selected for a task like this. You know what I
mean. There has got to be some limit on how much a process is helped or
hindered by the environment.
Dick
-----Original Message-----
From: Sellam Ismail <dastar(a)ncal.verio.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 17, 1999 4:15 PM
Subject: Re: z80 timing... 6502 timing
>On Sat, 17 Apr 1999, Richard Erlacher wrote:
>
>> Let's not start throwing up our respective hands in disgust! Nothing's
been
>> attempted yet. In fact, nothing's been suggested yet except a couple of
>> things which at first inspection didn't seem like they'd work. Now, Hans
>> Franke suggested something like a KIM-1. There's no reason one couldn't
>> code for something LIKE a KIM-1, even the guys working the Z-80 side, but
>
>You want people to have to learn 6502 in order to participate in this?
>So, I've never touched a Z80, but conversely you'd want me to have the
>added burden of having to learn Z80 assembler if we chose to do this on
>the Z80?
>
>I think part of the idea is to implement this exercise on different
>processors so that we can all collectively learn how the code to perform
>the same algorithm works on the many different varieties.
>
>> it's inappropriate to choose. If one wants the hardware, it should be
the
>> SAME hardware throughout the exercise, though. That's why I was
suggesting
>> a simulator. All that's really needed is a run to see if it actually
will
>
>Ok, Richard. You go off and write this simulator, and design the board to
>run it. Then when you're all done with this masterpiece, the rest of us
>will have long been done with this little mental challenge and talking
>about something more contemporary, like how two years prior the world
>did not in fact end on the January 1, 2000.
>
>> execute and end up with the desired result when code is submitted to the
>> hardware. A simulator would be adequate so long as it was trusted to
give
>> honest timing results. That way, nobody would have to risk burning his
>> fingers.
>
>I think counting clock cycles would be a lot simpler, but that's just me,
>always trying to find the sensible solution.
>
>Sellam Alternate e-mail:
dastar(a)siconic.com
>---------------------------------------------------------------------------
---
>Don't rub the lamp if you don't want the genie to come out.
>
> Coming this October 2-3: Vintage Computer Festival 3.0!
> See http://www.vintage.org/vcf for details!
> [Last web site update: 04/03/99]
>
I want to distance myself from the majority of this nonsense. Building a
simple computer with a processor, a ROM, a full compliment of RAM, and a
serial console interface is a 10-minute design and a 90-minute fabrication
task. If it's designed to fit already existing firmware/software, it's even
more or less practical to fit it into that firmware or software's
understanding of what the hardware is that fits with it. That means that an
operating system might be straighforward to accomplish in a day or two if
there's software in the form of a decent monitor or OS to support it.
HOWEVER, since there's little hardware support commonly applicable to both
of the subject processors, let alone for a number of others, It's silly to
consider anything but the simplest of hardware for a real-world
implementation. I'm sure most people in any way familiar with the things we
had to do back in the '70's will agree, that, from a hardware standpoint,
building a single-board system with 64K SRAM, Whatever size of EPROM you
like, overlapping it and disabled when copied into RAM, and a serial port is
a no-brainer, requiring , as I previously said, about 90 minutes to
wire-wrap. It might take longer if you have to find the parts. If you use
a WD FDD/HDD card, it will take another 15 minutes to wire up the cable
interface. If, however, you use just a WD1770 or 72 you have a floppy drive
as well. For the Z-80,that means you have CP/M. I don't know what's
comparable for 6502 development.
If you simply stop after the serial console interface, say,a 16C450 off an
obsolete but otherwise healthy PC serial board, you've got enough to run a
decent debug monitor. I have a couple for the 6502, though I was wanting to
incorporate the assembly/disassembly functions as well. That hasn't
happened yet, and until I'm properly motivated, probably won't.
Now I can't imagine why a graphics display, or anything so inane as that
could creep into the consciousness of an otherwise perfectly sane person
wishing to deal with one of life's fundamental mysteries, i.e. "which is
really faster, the XXXX or the YYYY?"
Dick
-----Original Message-----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Saturday, April 17, 1999 7:40 PM
Subject: Re: z80 timing... 6502 timing
>> Well, while you're at it, why not add a hard drive,
>
>1 or 2 chips for a SCSI interface...
>
>> a graphics accelerator,
>
>More nasty, at least if you want to keep it 'classic'. If I'm allowed
>bit-serial (like the MG1), perhaps a couple of dozen TTL chips at most.
>
>> a scanner,
>
>See above for a SCSI port
>
>> an ethernet adaptor,
>
>Oh, 3 or 4 chips...
>
>> a pencil sharpener,
>
>PIA chip + relay driver + relay to control sharpener motor.
>
>> and a juicer attachment?
>
>Ditto.
>
>>
>> Jesus Christ! Can't anything be simple for you, Richard? This is a
>
>You call that _complicated_ :-) :-)...
>
>-tony
>
'nuff said?
I saved a pair of these critters at the Paxotn auction, now need some docs
so I can figure out exactly what I'm dealing with here.
-jim
---
jimw(a)computergarage.org
The Computer Garage - http://www.computergarage.org
Computer Garage Fax - (503) 646-0174
>>> Coming soon to www.computergarage.org - the CBBS/NW on-line archives
>>> Coming to VCF III (2-3 October 1999) - CBBS/NW live!
--- Lawrence LeMay <lemay(a)cs.umn.edu> wrote:
> Well, I didnt say that I would pay $100... Or that it was a great price.
> But it might be a fair price.
>
> And i'd probably try to locate Lassiter and see if my some miracle he
> could repair the board, etc.
I don't get the reference.
> But, thats just me. To me, having a PDP8/e is the ultimate dream machine.
> That, and having the room to store a PDP8/e...
A PDP-8/e isn't all that large. Some of the peripherals can cause a
space problem...
-ethan
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--- Marvin <marvin(a)rain.org> wrote:
>
> The only real measure I have seen is on ebay, although others can talk about
> what goes on in the newsgroups. The last PDP-8i core stack ended at $76.00
> with 14 bids and the reserve was not met. The URL is:
>
> http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=91272199
>
That's me. I had the high bid. The reserve was $100. The seller is willing
to sell to me first if I pay the reserve amount. I personally was not unhappy
when the price was around $50. I didn't _really_ mind $76, but at $100, I'm
forced to consider it hard. I mean, I already *have* working core, several
stacks in working machines. I don't _need_ this, thus the debate.
Thanks,
-ethan
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At 11:52 AM 4/17/99 -0700, Ethan Dicks wrote:
>I am attempting to back up some floppies from a project I did a few years
ago.
>The sets of 3.5" 1.44Mb IBM floppies have been stored in a box, in a cool and
>dry room. Out of one set of 12 and one set of 15 disks, I have four disks
>that have read errors that DOS won't get past, bad sectors and the like.
>
>Are there any tools to go divining on DOS floppies that work better than
>an endless succession of "R"etries?
Try several different drives on different machines. Drives can be
out of alignment with respect to each other, and this includes the
machine that wrote the disk as well as the machines that read them today.
Try reading them on other types of machines, like Macs or Amigas with
proper DOS-reading abilities. Another good trick is to hold the disk
between your thumb and first finger, then whack each edge on the table-top.
Also, get out the can of compressed air to clean out each drive before you
try this, and open the shutter on each disk and blow them out, too.
- John
--- John Foust <jfoust(a)threedee.com> wrote:
> At 11:52 AM 4/17/99 -0700, Ethan Dicks wrote:
> >I am attempting to back up some floppies from a project I did a few years
> >ago.
>
> Try several different drives on different machines.
Done. Used a *new* drive in case my regular drive was dirty, too.
> Try reading them on other types of machines, like Macs or Amigas with
> proper DOS-reading abilities.
That was my next trick. The Amiga reads disks strangely (one track at a
time in MFM mode, then converts MFM to binary data by using a portion
of the graphics hardware to run a miniterm transformation on the buffer;
it uses a 4096-bit shift register in the sound chip to slurp up the track
in the first place, the major reason why C= sold 1/2-speed high-density
drives that work on Amigas going back to 1985 with no hardware modifications).
I'll try the Amiga route this week.
> Another good trick is to hold the disk between your thumb and first finger, >
then whack each edge on the table-top.
I've done that. My question is, how does that work?
> Also, get out the can of compressed air to clean out each drive before you
> try this, and open the shutter on each disk and blow them out, too.
I typically blow gently on the open shutter, being *very* careful to keep
the airstream dry. I am not blessed with a collection of canned air.
Thanks for the tips,
-ethan
_________________________________________________________
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This is sort of a heads-up. Even though I am the actual "seller", I'm
really putting this item up for a close friend. I'd buy it myself if I
could, but I'm in an anti-aquisition mode myself. It's an OSI Challenger 1P
computer + documentation
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=93182204
There are some nice piccies even if you're not interested in bidding.
HI to all :)
A
