None of my recent posts have made it into the digests (probably
because Hewlett Packard sent me a security certificate) but most
topics are now stale so I wont bore you with things like 160 column
cards, but I will retry this one:
One of my Flexowriters has just had its mains cable replaced and then
turned on for the first time in about 25 years. Apart from surface
rust and the printing levers not going back down, and the ribbon
breaking, it seemed to work fine. Does anyone know what grade(s) of
oils/greases to use on which parts? The rubber parts and carriage
return band even seem good but would probably not appreciate dunking
the whole thing in oil. I guess WD40 or "3 in 1" oil would be out
because I've been told they both leave a residue. I have not seen
anyone selling 'light machine oil' for a few years here in the UK but
there must be a modern version surely.
Now that is a printer that is worth keeping. Especially with the Jet Direct
card. As for the toner cartridge .... you can get one on E-Bay for probably
$20 to $30, or you can get refill toner with instructions for under $20.
Barry Watzman
Date: Tue, 07 Apr 2009 01:52:46 -0400
From: Curt Vendel - Atarimuseum <curt at atarimuseum.com>
Subject: HP Laserjet 4 free for pickup - Putnam, NY
Would anyone like a working HP Laserjet 4 with 10mb Jet-Direct Card?
Curt
I have a potential client who is looking for old iron (i.e. mainframes,
minicomputers, unit record equipment, etc.) in the Chicago area for a prop
shoot. There's not a whole lot of money involved, so I'm probably just
going to send the guy a contact list of those who respond to this inquiry
and let you work out your own deals.
If anyone has any mainframe sections or minicomputers in racks with lots
of lights and switches or keypunch machines, 9-track tape drives, etc.,
and they are transportable, then please contact me directly (off-list) and
I'll give you the details.
Thanks!
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
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> Date: Sun, 12 Apr 2009 22:02:54 -0300
> From: "Alexandre Souza" <alexandre-listas at e-secure.com.br>
> I have a 4+ with jetdirect and
> postscript (and globs of memory, of course). This is one sturdy printer I
> don't want to let it go. I just cannot justify a newer printer! Maybe if
> someday I get a color one for cheap...
Definitions of cheap vary of course. This past holiday season there were
at least three color laser printers priced at $200 shipped to (IIRC) $300
shipped with postscript and ethernet connectivity built in.
The Kyocera EP C170N was $200 shipped from buy.com and through Amazon but
fulfilled by an arm of Buy.com.
The Xerox Phaser 6180 was (again, IIRC) $250 from Staples with free shipping.
Both of the above models accept an optional duplexer, but the duplexer
costs about what the printers were going for.
The third model was something from Brother, I think, with the duplexer
included and priced around $300 from Newegg.
I bought the Kyocera model because it includes AppleTalk support--not
LocalTalk, but support for AppleTalk over Ethernet. I still have some
old Macs around (bringing this sort of on-topic) and the extra
compatibility is nice.
Jeff Walther
P.S. The KTM1523/512 Kingston 512MB module works as an upgrade in the
C170N, so the expensive Kyocera upgrade can be avoided.
>>> How does magtape avoid the stream-of-bytes issue?
>>
>> Magtape has blocks.
>
> What exactly is a block?
>
> Is it defined as a sequence of bits or as a sequence of bytes?
>
> If its just a sequence of bytes that define a block, I'm not sure I
> understand how blocks avoid the stream-of-bytes issue.
At the physical level, what really defines a block is that between
blocks there are inter block gaps which gives the tape drive time to
stop. If the CPU writes one block and then does calculations or (on a
machine with a multi tasking OS), runs someone else's job, the drive
must stop and wait for the next block to be written. Similarly on
reading, but because the drive does not know what will happen on
reading, then it has to provide inter-block gaps even when two block
writes follow on immediately from each other.
Having this physical structure means a tape can ONLY be read as a
sequence of blocks, you cannot just ask for n tape frames arbitrarily.
By the way, tape frames are really defined by the tracks on the tape,
9 track is 8 bits plus parity, 7 track is I think usually 6 bits plus
parity, (1 inch)16 track is 8 bits plus 8 CRC bits, 10 track is 4 bits
plus 6 CRC bits. There are of course many formats for 1/4 inch and 1/8
inch, and helical head formats, there was even a VCR backup system for
Apple ][ which worked with a VHS recorder and these add an extra
physical structure of stripes, though I think these were streaming
drives without CPU control of the tape deck, hence no proper inter-
block gaps, merely unused tape if the CPU could not keep up whilst
writing. Reading was I presume usually of individual files, so
stopping was not necessary.
Hello all,
I'm not sure how to put this, but I really hope someone on the list -- and local to me -- will buy this machine.
eBay item 270372433812. Sun Fire 6800 in Verdun (QC), pickup only. Zero bids, starting at 100 USD, 4 days left. Yes, all 500 kg. Even if, as the seller says, "my cute friends [in the photo] are not included".
I don't know the seller -- and notice his nonexistant feedback -- but what's the risk if it's "pickup only" and you've paid by CC or Paypal?
If you buy it, you have to invite me over to check it out. I couldn't take this machine even if one paid me to haul it away, unfortunately. :-(
- Alex
-------------Original Message:
Date: Sat, 21 Mar 2009 17:06:19 -0300
From: "Alexandre Souza" <alexandre-listas at e-secure.com.br>
Subject: Which way to go, from now on?
Ok, now what?
I had most of the 8 bits' computers avaiable in Brazil
I had most of the 16 bits' computers avaiable in Brazil
I had most of the 32 bits' computers avaiable in Brazil
I had most of the 64 (!) bits' computers avaiable in Brazil
I'd like to find a new journey. I was thinking about S100 computers, but
it is too expensive to play. I cannot find S-100 connectors here in Brazil
and boards to play are almost inexistent here.
Any suggestion of a nice project to keep me entertained? :o)
Thanks
Alexandre
----------Reply:
Where to go, what to do... a profound question indeed...
Why not join Andrew's happy little gang building and playing with the
N8VEM SBC? Sounds like a lot of fun.
I'm still waiting to hear from you about that PPT BTW... ;-)
I'm interested to learn the titles of some standard reference books on
electronic and microcomputer design from the early 1980's. I've been
reverse engineering many aspects of the Commodore Amiga. While I have a
decent library of Amiga books, I'd like to expand the collection to
include the "de facto standard" reference texts of the day --- to give
me more of an insight into the minds of the designers.
I've read some "history of the amiga" columns, "Life on the edge",
various interviews and so on.
If you could go back, what books would you find on the bookshelves of
these engineers? If you graduated college or a technical school in
1980, what were the popular reference texts used?
68000 reference books?
6800 reference books?
standard information on bus arbitration, or memory controllers, or maybe
LSI chip layout?
standard OS design practices?
I know I'm all over the place.
I've started playing with FPGA's and while I'm wholly unqualified to be
doing so, I'm enjoying it --- but would like to understand how this
stuff was done prior to the modern age. It's like learning the command
line first, so that when the gui-front end comes, you know what's
happening in the back.
Thanks
Keith
P.S. I'd almost be willing to bet there is one or two books called
"contemporary microcomputer design" or "contemporary electronic design"
both with a copyright date of 1980. I could be wrong. :)
I may be mistaken, but I believe that the Palantir board was one designed by
our own Jim Battle, if it is what I think it is - a board for OCR. (Back in
1987 I used the stand-alone Palantir OCR machine - a cheaper $25,000(?)
alternative to the Kurzweil unit - to scan in 1100+ pages of all the
Sherlock Holmes stories. It used 5 68000 CPU's and 2 MBs of ROM IIRC.)
Any comments, Jim?
Bob Stek
Former Saver of Lost Sols
Message: 5
Date: Mon, 6 Apr 2009 15:02:46 -0600
From: Mike Maginnis <mmaginnis at gmail.com>
Subject: A few free items
A few items to give away.
I came across a box of stuff as I was cleaning out the server room.
Might be of interest to someone, might not. I'd prefer local pickup
(Denver, CO area), but could be persuaded to ship if you cover S/H.
* Unknown board from "The Palantir Corporation" (c) 1988 - has a
Motorola 68020. 16-bit ISA. Maybe a co-processor board?
