Subject: Mark-8 Minicomputer Kit on E-bay

From: Mike <[email-masked]>
Date: Wed Mar 5 21:40:01 2003

Mark-8 Minicomputer Kit/Early Hobbyist First

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=177&item=3404840450&rd=1

Can I claim dibs?

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From: "Heinz Wolter" <[email-masked]>
Date: Wed Mar 5 21:40:12 2003

Dibs? No such thing on ebay ;)

I picked up a kit from this fellow on Ebay,
just the PCBs and chips- and everything looks
good.

As for dibs, you'll have to convince the other bidders ;)
Likely, the fellow mas many other kits available,
so email him. Personally I'd just buy the PCBs, hard
to get chips (CPU, latches, srams) and the toggle switches.
You can come up with a power supply and case yourself
and not get pay for their expensive shipping.

cheers
H.

"Mike" <[email-masked]> wrote
Subject: Mark-8 Minicomputer Kit on E-bay

> Mark-8 Minicomputer Kit/Early Hobbyist First
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=177&item=3404840450&r
d=1

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From: "Erik S. Klein" <[email-masked]>
Date: Wed Mar 5 21:40:35 2003

I saw this and asked the seller if it was an "original" kit from the 70s
or if it's a current reproduction.

I'm guessing it's current, but I'm going to wait for the reply (or ask
again since it's been a day or two).

It looks cool either way.

Oh, yeah: I had dibs first! :)

   Erik

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From: "Stuart Johnson" <[email-masked]>
Date: Wed Mar 5 21:41:06 2003

----- Original Message -----
From: "Erik S. Klein" <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, March 05, 2003 7:00 PM
Subject: RE: Mark-8 Minicomputer Kit on E-bay

> Oh, yeah: I had dibs first! :)

I saw another seller recently on eBay with a Mark-8 (reproduction) kit,
primarily the boards. He said that he was making the boards and would be
selling more. What I saw looked nice.

I looked briefly, but did not locate the auction or a link of any sort to
the seller. Perhaps one of the more interested parties can find additional
info.

Stuart Johnson

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From: "Erik S. Klein" <[email-masked]>
Date: Wed Mar 5 21:41:13 2003

> the seller. Perhaps one of the more interested parties can find
additional

I've been in touch with that other seller and even sent him a scanned
picture of a Mark-8 out of one of my old magazines.  I'll ask his
permission to circulate his email address for anyone interested in the
kits he's selling.

   Erik

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From: Bryan Blackburn <[email-masked]>
Date: Thu Mar 6 13:00:05 2003

It is most definitely a reproduction. It was made by Steve, AKA 
"obtronix". I've been watching him sell the exact same package on epay 
for a couple years now.

Bryan

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From: Ethan Dicks <[email-masked]>
Date: Thu Mar 6 13:03:24 2003

> "obtronix". I've been watching him sell the exact same package on epay 

What's a typical price?  I have been semi-interested in making one.
The only odd part I have would be an 8008 borrowed from a Unibus
console board (I have a few spare defective boards sets from Software
Results - turning machines on and off dozens of times per day to
insert and remove product under test is hell on equipment.  Naturally,
DEC Field Service would not cover equipment under such use, at least
not affordably).  The oldest SRAMs I have are 2101s; I have never 
even seen a 1101 close up, so I guess I'd need the whole enchilada
when it comes to "odd parts".

BTW, is there still a source for the old-style strip sockets?  I'm
sure that machined pins are a "better choice", but I was curious if
it was still possible to get period mountings.  (what I tend to do
if I need to see under sockets for stuff I'm building is to scavenge
individual machine pins from busted sockets and attach them under
a pristine socket and solder them in place - not necessarily as
mechanically stable, but at least you can see the traces).

-ethan

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From: "Erik S. Klein" <[email-masked]>
Date: Thu Mar 6 13:03:54 2003

>"obtronix". I've been watching him sell the exact same package on epay 

I contacted Stephen last night to see what he was up to.  As it turns
out, the kit on eBay is one of his that the buyer probably gave up on or
never had time for.

He's planning to make some more kits and he's working on a web site:

http://mark8.obtronix.com/
http://mark8.obtronix.com/gallery/

It looks like he's off to a really nice start!

Erik S. Klein
www.vintage-computer.com

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From: Bryan Blackburn <[email-masked]>
Date: Thu Mar 6 13:11:14 2003

>What's a typical price?  I have been semi-interested in making one.
I have seen them go for between $200-$1000+, depending on the 
completeness of the parts package. The last fully assembled one I saw 
went for a little over $3000 (For the soldering iron challenged).

>BTW, is there still a source for the old-style strip sockets?  I'm
You can buy them almost anywhere. Digikey, I think, has them. I buy them 
from local parts stores.

Bryan

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From: "Eric Smith" <[email-masked]>
Date: Thu Mar 6 22:19:21 2003

Ethan wrote:
> BTW, is there still a source for the old-style strip sockets?  I'm sure
> that machined pins are a "better choice", but I was curious if it was
> still possible to get period mountings.

Machined-pin sockets were available back then (e.g., Augat), and
that's what anyone sensible used if they could afford it.  So there's
nothing wrong with using machined-pin sockets to build one today.  New
machined-pin sockets are not any less "authentic" than new dual-beam or
single-beam sockets.

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From: "Jim Kearney" <[email-masked]>
Date: Fri Mar 7 16:26:21 2003

> The oldest SRAMs I have are 2101s; I have never 

I've been hesitant to bring this up here because it skates perilously 
close to the kind of commercial messages that are so annoying, but here 
goes: when I built my Mark-8 (from Steve G's boards), I located some 
NOS Intel P1101's.  I later found some AMD C1101's that look nicer, so 
I never used the Intel chips, and I would like to pass them on to 
someone who would use them.  However, they (being of 1973ish vintage 
and rare) cost me a fair amount, $4 ea, and I'd need to recover that.  
I think I have 26 of them, so 3 banks totalling 768 bytes.

Jim Kearney

p.s. my Mark-8: http://www.jkearney.com/8008/

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From: "Jim Kearney" <[email-masked]>
Date: Fri Mar 7 16:30:25 2003

> I'm wrestling with a partial redesign or a complete replica.  I guess
> if I had the total costs laid-out in column A and column B format,
> it would be easier to decide.

The Mark-8 design is markedly inefficient; ones with many fewer ICs are 
pretty easy to come up with.  It's not especially anachronistic to use 
2112's or 2101's, which are relatively easy to come by.

> Were you besiged by requests?

I wouldn't say I was inundated, but I'm happy to say that will be going 
to someone who will put them into an actual 1976 Mark-8.

> Nice.  You did one run of boards?  How much did they cost?

Thanks.  No, I got the basic board set from Steve Gabaly, who's been 
selling them on and off for a couple of years.  He seems to be actively 
selling again, as 'obtronix'.  

Jim

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From: Ethan Dicks <[email-masked]>
Date: Fri Mar 7 16:30:34 2003

--- Jim Kearney <[email-masked]> wrote:
> However, they (being of 1973ish vintage 

I'm wrestling with a partial redesign or a complete replica.  I guess if
I had the total costs laid-out in column A and column B format, it would
be easier to decide.

-ethan

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From: "Heinz Wolter" <[email-masked]>
Date: Fri Mar 7 16:31:00 2003

----- Original Message ----- 
From: "Jim Kearney" <[email-masked]>

> 2112's or 2101's, which are relatively easy to come by.
If you were wirewrapping or point to point soldering, you 
might consider 2114 static rams. Might be easier to get
hold of thah 2101/2102s or 1101, but they won't fit into
the original or copied Mark-8 boards. 

The pain and weakness of  the Mark 8 design is the bus
connection scheme- soldered wires and molex across the top.
It would be better if you can use RA SIP connectors..

heinz

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From: Ethan Dicks <[email-masked]>
Date: Fri Mar 7 16:31:14 2003

> the original or copied Mark-8 boards. 

Personally, I have quantities of 2114s left over from the COMBOARD-I
parts tubs (32K of SRAM each) and plenty of dud COMBOARDs I could
strip if I *ever* ran out.

As has been discussed here, though, they have long-term reliability
issues, but they are still widely available.  BG Micro stocks them
as well as 2102s, IIRC.
 
> connection scheme- soldered wires and molex across the top.

It's ugly and prone to problems, I know.

If I can find a quantity of 44-pin .156" proto hardware at Dayton
this year, I'm considering wrapping my own.  I need a supply of
WW wire, too... I'm down to two spools.  I need some 44-pin cards
anyway for Commodore and Cosmac VIP projects.

-ethan

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From: "Jim Kearney" <[email-masked]>
Date: Sat Mar 8 02:30:00 2003

> strip if I *ever* ran out.

2114's don't quite feel 'right' to me for a period 8008 computer.  I 
guess it's because I had an 8008 in 1976 but no 2114's until 1979.  
Personally I would stick to 2102's or 2112's, but that's entirely 
subjective.

---

From: "Heinz Wolter" <[email-masked]>
Date: Sat Mar 8 02:31:21 2003

Ethan Dicks wrote:
...
> issues, but they are still widely available.  BG Micro stocks them

I know - they're very static sensitive - and extremely power hungry!
when they go, they get even hotter ;)
...
> anyway for Commodore and Cosmac VIP projects.
Radio Shaft used to carry these - they were my fave proto boards
as a teenager - being my last resort for parts, but the only source
for people living in small cities, Radio Scrap hardly carries anything
useful to the hobbyist. They do carry a not half bad wire wrap tool
but their ww wire was prohibitively expensive. I picked up a couple
of 1000ft rolls of flourescent orange and red from the local surplus place-
so I've set for a while. I've seen deals on teflon, but it's too hard to
strip.
I'd love to get one of those professional ww guns though - make life alot
easier for my half dozen ww projects currently in progress...
-heinz