> >> Being unmarried means I get to put my server rack
> in the dining room.
> >> That's better than sex.
> > This is real geek porn:
> > ftp://ftp.franken.de/pub/people/m/pix/comp/
>
There's someone that has taken Kraftwerk a little too seriously. . . .
http://music.yahoo.com/Kraftwerk/Computer-Love/lyrics/656721
I'm not sure if I'll ever be able to look at my 11/83 the same way
again. ;-)
T
>
>Subject: Re: non-CP/M Z80 board
> From: Dave McGuire <mcguire at neurotica.com>
> Date: Wed, 18 Jun 2008 23:13:54 -0400
> To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org>
>
>On Jun 18, 2008, at 11:48 AM, Chuck Guzis wrote:
>>> They're all over the place. I have at least one tube of *brand
>>> new* NMOS Z80 (not-A) chips here...cost me all of three bucks on eBay
>>> in '06 or so. Need any?
>>
>> I think the chips under discussion were the 8085 specialty chips,
>> 8155, 8355, 8755, etc. Got tubes of those?
>
> I've got a dozen or so 8755s, two or three 8155s, and no 8355s.
>Not tube quantities, unfortunately.
>
> -Dave
I do. Several tubes of 8755A, 8155A, 8156A and 8085A and some A-5s.
Those parts are not that uncommon and they did have multiple vendors.
Most of the Z80 (2.5 ->8MHZ) and peripherals are available from
many vendors including JDRmicrodevices. Not all the peripherals
were availble to 8mhz though (DMA was never made faster than 4mhz
if memory serves).
Allison
>--
>Dave McGuire
>Port Charlotte, FL
>
A couple years ago there was talk about AV mods for the Atari 2600. Does
anyone here have a Cybertech AV mod? How is it different from the
standard CD4050 hack?
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
> Date: Wed, 18 Jun 2008 09:24:05 -0400
> From: Dave McGuire
> > Are those parts even around any more though? Easy enough to find?
> > I haven't
> > looked in a while...
> They're all over the place. I have at least one tube of *brand
> new* NMOS Z80 (not-A) chips here...cost me all of three bucks on eBay
> in '06 or so. Need any?
I think the chips under discussion were the 8085 specialty chips,
8155, 8355, 8755, etc. Got tubes of those?
Cheers,
Chuck
>> The monetary value of something is the price that a seller and buyer
>> are willing to agree to. If a replica sells for $2000, then its
value
>> to the seller and buyer must be $2000.
>
> I can't tell whether the responses along these lines are honest
> misunderstandings or well hidden sarcasm.
>
> We all know the sale price of this item. One sale does not a trend
> make. Why can't someone provide either a useful answer or some
useful
> information?
I don't know that there is an authoritative answer to that,
or to most other "what's it worth" type questions about vintage
computer equipment.
Consider for example "The Antiques Roadshow",
or auction houses like Sotheby's.
There are a number of folks out there who are experienced
at appraising artwork, old furniture, classic automobiles, and a
plethora of other items. Most of which has been around for
many many years.
Can the same be said of the computer and/or electronics industry?
I think the market is still in it's infancy, and there's probably not
enough interest in the vintage equipment to support expert opinions.
(Yet.)
Case in point: Check out this VERY cool Predicta television:
http://www.flickr.com/photos/72154009 at N00/2186381451/
I'm sure there are a number of folks out there who could give you
a reasonably accurate opinion about the overall value of this unit.
This is in part due to the niche market interest in old electronics
such as this. And it's been around for a number of years.
Now, who could tell me definitively, the "value" of this 1976 Magnavox?
http://www.tvhistory.tv/1976%20Magnavox%20TV.JPG
Probably not a whole heck of alot of people.
There were a large number of them made.
But there's not alot of interest in it, because it's
still "fairly" new, and by the time it started to wear out,
we had moved into an age when people didn't hold on to
their old electronics, they just threw them out, and got new stuff.
I find that people who ask "what's it worth?" can be divided
into two categories. Either they haven't a clue, and are
too lazy to do the research, or, they have an idea of what
they want, but don't want to lose out by paying too much,
or charging too little. Buyer's / Seller's remorse.
Do the research! Find out what they've sold for in the past.
Look at ALL the prices, high and low, and see if it jibes with
what you think it's worth. And don't assume that you'll get the
same amount as others have; there are simply too many variables.
Research is sometimes very difficult with unique or
limited-availability items,
which brings us back to the original topic:
Is a potentially non-working Apple I clone worth $2000 to me? No.
Is it worth $200 to me? No. But then, I'm not a collector of Apples.
As a rule of thumb, we shouldn't be asking the question
"What does someone else think it's worth?", we should be asking
the more important question, "What is it worth TO ME?"
This applies to both buying and selling.
Either way, if you buy and sell based on the opinions of
a limited number of people, you'll eventually end up getting burned.
Um, yeah. . . If you give me $10,
I'll be happy to haul away that old Altair for you. . . ;-)
Regards,
T
-------------------------------------------------------------------------
------
Note: The opinions expressed above do not necessary
reflect the views and opinions of the author.
The 279x (1,3,7) series chips actualy had a working pll data seperator.
Here is a link to the 279x controller chip data sheet:
http://retrotechnology.com/herbs_stuff/fdc_datasheet.pdf
As I recall, the 179x series chips could not reliably do sector reads from disks formated on a 177x controller. The 179x could do a track read of the disk. Morrow provided a program with the Disk Jocky controller which would do track reads, then write the track back out creating a disk which worked well with either the 177x or 179x series controllers. It was not a common issue, as very few people used single density once double density became available, and new single density disks worked well with either controller.
Les
----------
From: M H Stein[SMTP:dm561 at torfree.net]
Sent: Wednesday, June 18, 2008 9:38 PM
To: 'cctalk at classiccmp.org'
Subject: time to part with my PDP-11 system
----------ORIGINAL MESSAGE:
Date: Tue, 17 Jun 2008 01:52:09 +0000
From: Ethan Dicks <ethan.dicks at usap.gov>
Subject: Re: time to part with my PDP-11 system
On Mon, Jun 16, 2008 at 03:26:15PM -0400, M H Stein wrote:
> Date: Mon, 16 Jun 2008 03:54:51 +0000
> From: Ethan Dicks <ethan.dicks at usap.gov>
> Subject: Re: time to part with my PDP-11 system
>
> <snip>
> >...Eventually, I'll do another camping trip to Hamilton...
> <snip>
> -ethan
> ---
>
> I'm in Hamilton every week or so, and I have to ask: why?
> ;-)
The serious answer is because I have friends who live in an arc
between St. Catherines and the west edge of Toronto, and every
June since the early 80s, they've done a largish camping event
somewhere in the Hamilton area (Knight's Dunmark Park is where
it was 20 years ago, but that was turned into a golf course).
While these friends aren't into classic computers at all, it
does give me incentive to spend the gas to drive 7-8 hours
>from central Ohio, and puts me in that area for quick little
side trips (like to Jerome's house) every few years.
-ethan
-----------REPLY:
Ah, that explains it; although it's actually a very nice place aside
>from the steel mills and smelters, Hamilton's not really known as
a tourist hot spot.
If and when you do get up here again, I'd love to meet for a coffee
and say hi; haven't seen Jerome in many years either despite
being in the same city, but then I'm not a DECcie...
Looking forward...
mike
**********************************************************************
Does someone have a website of Tandy manuals who'd like to host the scans
of the user and service manuals for the PT210 printing terminal? I've
been hosting them for a while, but I don't have very much bandwidth to
spare.
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
Hi All,
Seth just built his N8VEM SBC and it worked on the first try!
Congratulations Seth! Great Job!
Andrew Lynch
PS, this is also an important milestone; it is the first of the shipped SBC
PCBs I know of to see "first boot" in the field.
-----Original Message-----
From: n8vem at googlegroups.com [mailto:n8vem at googlegroups.com] On Behalf Of
Seth Morabito
Sent: Wednesday, June 18, 2008 2:28 AM
To: N8VEM
Subject: [N8VEM: 108] Re: How are things going for builders?
P.S.:
The completed board: http://www.flickr.com/photos/twylo/2588823197/
The software, in action: http://www.flickr.com/photos/twylo/2588826647/
-Seth
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"N8VEM" group.
To post to this group, send email to n8vem at googlegroups.com
To unsubscribe from this group, send email to
n8vem-unsubscribe at googlegroups.com
For more options, visit this group at
http://groups.google.com/group/n8vem?hl=en
-~----------~----~----~----~------~----~------~--~---
bfranchuk at jetnet.ab.ca bfranchuk at jetnet.ab.ca
<mailto:cctalk%40classiccmp.org?Subject=Emailing%3A%20CP-M%20Z80%20home%20br
ew%20computer%20circuit%20board.htm&In-Reply-To=CAD07A50FEA44B73BFD2864883FC
644B%40andrewdesktop>
Sun Jun 15 20:05:45 CDT 2008
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________________________________
Andrew Lynch wrote:
> That means compromises had to be made and some stuff had to go.
>
> Anyone can design a great computer on paper. Making a real, tangible part
> is a lot more difficult.
>
> Using cool sounding but almost impossible to find parts seems easy but it
> makes the SBC practically worthless.
>
> If you can make a low cost Z80 SBC that includes floppy IO, I would love
to
> see it. I'd even buy one or two.
>
But when you think about it, most early CP/M machines were
8 inch single density. Not much on a disk and that I think is
the basic format to look at. I think I seen a data separator
using a 16 bit counter at 4x? the data rate but I can't remember
where.
> I look forward to seeing your design.
>
> Thanks and have a nice day!
>
>
I can't say I am having a nice day.
I am still grumbling over not getting PAD's
PCB and LAYOUT software when I could in
the late 80's. I am looking to do a 16 bit
(2901) cpu using EEPROM (2kx8 250 ns)
and am still trying to find a schematic capture
and PCB layout program that I can afford
with through the whole parts.
Sadly all seem to be Australia. :(
> Andrew Lynch
>
>
>
Well, as my Mom likes to say "Talk is cheap. It takes money to buy
whiskey."
Data separators require either available chips or replacements with specific
details.
I designed an FDC data separator using plain 74LSxxx parts which is great in
theory but there is no way I am going through the expense and time to build
it when there are more pressing things to do. There is no guarantee it
would work either. I am just an engineer, not a magician.
If you look closely at those old 8" SSSD 8080 CP/M machines generally they
use lots of SSI TTL and large PCBs.
Were a similar computer designed today, it would cost a LOT of money to
produce. They cost a lot then too.
A home brew SBC using PCB of those sizes would be prohibitively expensive
for most people.
As for low cost EDA tools, have you tried KiCad and FreeRouting.net? There
are links on the N8VEM website: http://groups.google.com/group/n8vem
Originally, I designed the N8VEM SBC on notebook paper by hand. Later I
recaptured the design with KiCad and used the FreeRouting.net
autorouter/manual router.
The N8VEM hardware documentation is done using KiCad/FreeRouting.net to
create schematics, PCB layout, Gerber files, drill files, BOM, netlist, etc.
KiCad is free (beer, speech) and FreeRouting.net is free (beer).
They do a great job of schematic capture, PCB layout, have fairly complete
parts library, have the ability to make custom parts, and do a great job of
both autorouting and/or manual routing of PCB traces. Total cost $0.
I doubt you'll find a 4 bit wide bit slice CPU (AMD2901) in the KiCad parts
library. That part is a bit obscure these days. However, it'd probably be
easy to do a custom part model since it is a plain 40 pin DIP with normal
IO.
The EEPROM is probably a 2816 or similar and is already in the extended
parts library.
Thanks and good luck with your project!
Andrew Lynch
So much for his friend giving him $1500 for it...
It was a scam attempt, plain and simple. Just so happened he got BuStEd in the process, which I am
SURE he did not expect - I assume he thought he was selling it in the land of the dimwits.
He could not have been more wrong.
With such a small number of originals, and him KNOWING THAT, I don't understand how his little brain
concocted what has to be the stupidest idea, and lamest execution, that I've seen in quite a while!
It was a failed attempt - too many loose ends, too many trackable things, and a LOUSY job of hacking up
the cassette adapter... Not to mention an EXTREMELY limited item with the following of a sports franchise!
Those of you thinking otherwise, and are giving him the benefit of the doubt, boy, have I got some REALLY NICE land out here for you in Southwest Florida.....
Tony
-----Original Message-----
From: Al Kossow aek at bitsavers.org
Sent 6/16/2008 11:43:38 AM
To: classiccmp at classiccmp.org
Subject: Apple I back up on ebay
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220246863432
only change from the original listing (along with dropping the price).
"Up for bids is an Apple I Computer, many experts believe to be infact a good
reproduction (of witch about 150 where made - my knowledge of more info is
limited) in good shape. One of the genuine ones recently reported selling
for in excess of $50,000, and with good reason, experts believe there is only
20-30 in existence of the original 200 handmade by Steve Jobs and Steve
Wozniak in early 1976."
For those intersted in DEC equipment and one aspect of their their usage (UK
I'm afraid)
Details of a now defunct Military installation that used various DEC
computers has recently gone online.
These documents from about 1980 show PDP 11/10's and 11/40's used for jet
engine research and how they were utilised.
I was the tech involved in the installation of the 11/40 in the mid 1970's,
and maintenance at that time of the PDP7, SDS9300 and Elliot 803B systems. I
also lists an ICL1904s running George Mk 8.64.
It was all decomissioned in 2002, who knows where all the kit went but the
urban explorer forums say it has all gone. Typical UK government, we dont
want it so nobody can have it.
Main document - http://www.ngte.co.uk/doc/doc/etf1.htm
Data processingsection - http://www.ngte.co.uk/doc/doc/etf5.htm
Mike.
>
>Subject: Re: CP-M Z80 home brew computer circuit board
> From: "Eric Smith" <eric at brouhaha.com>
> Date: Tue, 17 Jun 2008 11:53:23 -0700 (PDT)
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>Allison wrote:
>> As long as you can poll within the minimum read/write loop
>> time it's fairly easy. If not in the 8080/8085/z80 world you can use
>> processor ready line to do a stall-wait on DRQ to keep the loop in
>> sync and save some 22 T-states.
>
>I think you also need some logic to release the ready line if DRQ
>doesn't occur but an interrupt does, in order to handle error
>cases.
With the 765 you can OR the DRQ and the INT lines for that. Likely
that works for 179x (and friends)as well.
>
>> I forget if 6502 has a ready wait line.
>
>It does, but on the NMOS parts it only can stall read cycles, not
>writes. (In the early-to-mid 1970s, ROMs and EPROMs were much slower
>than typical SRAMs, so the designers apparently didn't think there
>was any need to stall on writes.)
I know so well Eproms were slow.
>
>For the controller I designed, I dealt with that by having a special
>address that could be read that only waited for DRQ, at an address
>in the page below the FDC's data register. By itself, that wasn't
>sufficient to get to 8" MFM on a 1 MHz 6502. However, by taking
>advantage of the spurious read that occurs on indexed write
>instructions when there is a page crossing, I got the read of the
>special polling adress and the write of the data in a single
>instruction. That gets it down to 16 cycles, which meets the
>nominal rate but isn't actually good enough. By unrolling the
>loop, though, it drops to 13 cycles per byte, which meets all
>the requirements:
Thats pretty crufty.
> LDA (DPTR),Y ; get data byte from buffer
> STA FDC_SPCL,X ; reads poll location, which stalls,
> ; then writes data
> INY
>
>The unrolled loop requires 6 bytes of code per byte transferred, which
>is 1536 bytes for a 256-byte sector. Not great, but it did fit in a
>2716 EPROM. I used two 2716s, one containing the read loop and one
>containing the write loop, both mapped into the same address space
>and selected by writing to another port address. The rest of the
>FDC driver fit in the remaining space of the two EPROMs.
>
>I didn't anticipate that they would "fix" the RDY behavior and the
>spurious read on the 65C02, so the same code wouldn't work on that.
>However, the fix was simply to replace the indexed STA with an
>absolute STA.
Don't you love it when that happens. In the 8080/8085/z80 world that
kind of processor tweek was less common by vendors as absolute
compatability with intel (the compatition) was desireable.
However having done that far to many times for many different cpus
I'll pass on further floppy integration. CF or even IDE gets me
to enough space and decent speed with far less pain.
Allison
>Eric
On Tue, 17 Jun 2008 David Griffith wrote:
> So, what's the value of the replica anyhow?
Hehe. I guess it's worth whatever someone is willing to pay for it.
I just found it surprising that someone still bid,
after all the various revisions to the auction.
Heck, even the 2nd auction was edited once or twice
after it was posted. It was most unusual.
I'm still puzzled as to why he indicated that it
came from a collector, and that there was a
display case. . . but then went on to say that
it was covered in a layer of dust.
Normally, you put items in display cases
to AVOID human hands, dust, and dirt.
But, I digress. It's over with.
We should move on to more important things. . .
. . . like the 11/73 system that I just listed on e-bay.
It's alot less expensive, and one can be reasonably sure
that the processor isn't a knock-off. ;-)
T
From: "Chris M" <chrism3667 at yahoo.com>
Sent: Sunday, June 15, 2008 8:26 PM
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Subject: any building 6800 sbc's out there?
> just curious. When I started piddling around with this
> stuff in the late 80's I guess, that was one of the
> chips I intended to use as the basis for probably a
> small breadboarded computer. Never got around to it.
> But I did *swipe* a coco off of a friend and played
> with that for a spell (6809 based). Close enough! :)
Oh, 6800 stuff. Brings back many old memories. When the 6800 was released
back in 1975 (+- 1 year) I had the great idea to build a ham radio repeater
controller. In the process I ended up doing a bunch more. Eventually we had a
bunch of "cards" that used 44 pin edge connectors (look, it is what I had at
work) and it worked out quite well. After the repeater project, I did some
work in testing Qume printers (you remember the Daisy Wheel things) and ended
up writing a small operating system using single density minifloppies and a
WD1771 controller chip (much better than discrete hardware!!). The data rate
was slow enough (64 us/byte) that I could get away with having the data use the
non-maskable interrupt to transfer data. Somewhere I've got some of the
hardware from that era. The boxes could be maxed out at over 60k bytes. One
of the 'projects' I ended up doing was the basis of a company I worked at from
'78 thru '83. One interesting thing was that GM had a special chip made that
plugged into a 6800 socket, and ran 6801 code at 6801 cycle times (about 20%
faster!). We got a couple and the system I've got in the garage still has it
working.
Never did get into S100/CP-M stuff. Oh, well.
I'm thinking about building a z80 board, with varying amounts of "stuff"
attached, with RAM and ROM that may be NMOS or CMOS, and some indeterminate
number of Z80-family and compatible peripheral chips.
My question is this: At what point do you _need_ to have address and data bus
buffer chips?
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220246863432
only change from the original listing (along with dropping the price).
"Up for bids is an Apple I Computer, many experts believe to be infact a good
reproduction (of witch about 150 where made - my knowledge of more info is
limited) in good shape. One of the genuine ones recently reported selling
for in excess of $50,000, and with good reason, experts believe there is only
20-30 in existence of the original 200 handmade by Steve Jobs and Steve
Wozniak in early 1976."
IIRC, when there was only the NMOS Z80/Z80A parts, this was one of
the reasons for the popularity of the Intel 8085. You could put
together a functional system for a dedicated application with some of
the made-for-8085 peripherals (e.g. 8155, 8355, 8755), with a very
low chip count compared to what's needed for an equivalent Z80
implementation.
Cheers,
Chuck
On Tue, Jun 17, 2008 at 8:33 PM, Zane H. Healy <healyzh at aracnet.com> wrote:
>
> You should also be able to find a dirt cheap, piece of crap Chinese EPROM
> eraser that will do the trick off of eBay for about the same price.
I just bought one of these dirt-cheap, piece of crap Chinese UVPROM
erasers on Friday. It should be here tomorrow. I'll let everyone
know whether it's capable of erasing anything once I've given it a
whirl!
(My modern electronics buddies practically did a spit-take when I told
them I was still working with UVPROMs! The irony is, I'm only just
now getting into this stuff, so 'still working with' isn't quite
correct, either. I'm perfectly happy to be stuck in the past!)
-Seth
Emailing CP-M Z80 home brew computer circuit board.htm
Eric Smith eric at brouhaha.com
<mailto:cctalk%40classiccmp.org?Subject=Emailing%20CP-M%20Z80%20home%20brew%
20computer%20circuit%20board.htm&In-Reply-To=D56A2F9DFFEA45C791E59FE9F179D5B
9%40andrewdesktop>
Tue Jun 17 19:54:54 CDT 2008
* Previous message: Emailing CP-M Z80 home brew computer circuit
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* Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
________________________________
Andrew wrote:
> Still how do you transfer stuff from a floppy ( or file online ) to a
> CP/M system with no external I/O devices?
I wrote:
> I have yet to see a CP/M system with no external I/O devices. That
> doesn't sound very useful, so why would one care about transferring
> stuff to it?
Andrew wrote:
> Who said the N8VEM SBC has no external devices?
I was replying to your question, quoted above. I never said anything
about an N8VEM SBC.
Eric
-----REPLY-----
Eric,
Oh, I think I see what happened. The quote you attributed to me is actually
>from Ben.
Everything I said is below the -----REPLY-----
I never asked that question and wondered why you asked it. Still, the
response is valid.
BTW, the N8VEM SBC is the actual name for the home brew Z80 SBC I built.
I am offering the PCB to others of similar interests.
Probably there has been enough discussion from me on the topic.
If anyone is interested please contact me offline or join us on the N8VEM
google group:
http://groups.google.com/group/n8vem
Thanks and have a nice day!
Andrew Lynch
73 de N8VEM
Hello CCtalk,
I'm hoping someone can help me with the pinout for the power connector
of a CDC 9410 Finch 8" 32MB harddrive. It has a power interface that I
haven't seen on other 8" drives. If you would like to see pictures:
http://www.dusicyon.org/temp/cdc01.jpghttp://www.dusicyon.org/temp/cdc02.jpg
I appreciate any advice or suggestions you can give.
Thank you,
Theo Wiegmann