I was looking at a couple of documents describing the Pertec tape interface; the manual for my Kennedy 9610 tape drive, and a nice reference by a fellow with a rather familiar name:
http://www.sydex.com/pertec.html
According to my Kennedy manual, issuing a read command causes the drive to return one block of data. I can see how that would be used in block-oriented applications in which blocks may be randomly read, written and re-written on the tape. But most of my magtape experience has been using the tapes in a streaming mode, such as when reading/writing one or more tar archives separated by file marks.
When writing a tar archive on a magtape from a Unix system, is the archive written as a sequence of fixed-size blocks? Or is the entire tar archive effectively written as one continuous block which must be streamed with no repositioning?
I'm curious because I'm daydreaming about how to build a tape drive interface controller, and I wonder whether it might need to potentially stream an entire tape in one go vs. being able to safely assume some maximal block size.
--
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/
The silence may have led you to believe that it was all over. Oh no...
The 10th Vintage Computer Festival is a GO!
Bigger, bolder, nerdier than ever, a wonderful way to tack on our
second digit, VCFMW10 will be held August 29-30 at the Holiday Inn
Chicago-Elk Grove Village. A remarkable convergence of amenities and
price have come together in this spot. Among the features:
- A single 4550 sqft banquet hall - at long last, VCFMW and ECCC shall
truly be one!
- First-floor facilities - no more elevator rides or Level of Discharge!
- 11'x12' loading doors that open direct to the parking lot - you
could drive a truck right into the ballroom, but don't!
- A separate room for talks, videos, quiet time, etc - like we're a
real conference or something!
- No (known) conflicts with holidays, wives' birthdays or other local events!
- The quaint, vaguely Blade Runner-esque surroundings of industrial
parks, truck depots and factories - just the way we like it!
- An on-site restaurant, pool, exercise room, outdoor firepit/smoking
area, shuttle buses to/from the airport and Woodfield mall, close
proximity to fast-food and the two greatest Chicago eateries,
Portillo's and Lou Malnati's! (Seriously, those two alone are reason
enough to attend.)
I have updated the http://vcfmw.org web page and FAQ with most of the
information we have so far. Please give them a read before posting
questions. Hotel room rates will be slightly higher than last year's
$79 at the Fairfield Inn; I am still negotiating the block rate. Due
to the restaurant being on-site, there will be no continental
breakfast. Sorry :(
Now the hard sell: all of this geek-luxury does not come without a
price. Some of you know that the deal we had at the Heron Point was
extraordinary and unheard-of in the event hosting business. Since the
HP no longer rents to the public, we were faced with the choice of
resting on our successful nine-year record or figuring out a way for
the show to go on. And go on it shall...with your help. Without
getting into specifics, the cost of putting on VCFMW has more than
doubled - and we are getting a bargain if our comparison shopping is
to be trusted.
Donation links have been set up on the main VCFMW page for PayPal and
GoFundMe sites. Please use the GFM only if you do not have a PayPal
account, as GFM charges us a fee. If you'd prefer to donate in
person, contact me directly. I will get you a receipt (sorry, we're
not a 501.3c yet, so it won't be tax-free.) The main site features
our non-patented Donate-o-Meter which will (more-or-less) track our
progress. We have a lot of time to reach our goal as payment is not
due until the day of the show.
Extra money raised will be either spent on bonus features for the show
(more space, pizza bar, etc.) or put into a fund for next year. We
will engange with the community as much as possible before making any
decsion regarding extra funds.
There will be much to do between now and August - a new floor plan to
design, tables to allocate, speakers to recruit. But our first big
task is one where everyone can help: let's get the word out! Many of
you are on forums that I am not, so spread the news: the show will go
on!
-j
>
> On Dec 17, 2014, at 7:35 AM, Al Kossow wrote:
>
> > I should have one, somewhere.. Bear or Earl probably have one as well.
>
> Apparently I don't have an XY472, or at least one doesn't show in
> inventory. I was totally ready to jump in and save the day, too!
>
> ok
> bear.
I'll try to check tonight when I get home... spreadsheet says I have 8
Xylogics SMD controllers... have to see if any is an XY472.
Earl the Squirrel
Dave Tumey sent us a new rubber hammer for the Teletype. This is the part
that pushes the print drum against the ribbon and paper to print. These are
newly molded parts that have not been available for decades. Works very
nicely.
The ripple on the power supplies is still going lower as we put more run
time on the system. The power supplies are now within spec.
Warren wrote a better memory checkerboard program that shows the bits that
were being picked up or dropped in the MQ register. We tried adjusting the
STROBE FIELD 0 delay about +/- 100nS, but there was no setting that
resulted in completely working memory. Changing the delay did change the
location and number of bits that were picked up or dropped. Since the
failing addresses were all above 1000 we tried replacing the G221 modules
in slots C07 and C08. There was no change. We suspect that we have a
problem in the inhibit circuits.
Warren made an Arduino based programmable baud rate generator that works
for both serial ports. After some debugging, it works nicely.
The donor dropped off the work table that goes in front of the PDP-12. We
need to loosen the rusted feet so it will fit under the front panel.
--
Michael Thompson
Last week while bored and browsing eBay looking at things that are ending soon something I had never heard of caught my eye: an Altos ACS 8000-15A. I looked at the pictures and googled the brand and model and it didn?t seem to be a very common computer and there were no bids on the item so I put in a fairly low bid. I ended up winning! :-)
The seller asked if it would be ok to bring the item to me the next time he was in my area. I figured that was fine since I was concerned that since it has a large 8? hard drive in it that it would be more likely to be damaged in shipping. I actually didn?t even need to wait very long! Friday he set out to drive across 2 states and dropped off the computer at my front door on Saturday morning. Talk about excellent service!
I buy lots of untested items on eBay and usually they work just fine. But luck hasn?t held for me this time and so far the Altos doesn?t work. I can hear the drives spin up and all the voltages from the DC power supply are perfect. But nothing spits out on the Console 1 RS232 port. From what I understand the serial ports are wired DTE (which seems odd since you use it with terminals) and so I?m using a null modem adapter. Although with the null modem or without I get nothing.
Anyways, I posted an album with lots of pictures here:
http://imgur.com/a/9X8Gh
Yay another project for me to fix! :-)
--
Follow me on twitter: @FozzTexx
Check out my blog: http://insentricity.com
FYI - in the fairly near term, I plan to get rid of the "two views of the
same list" configuration on the classiccmp server. It has always created a
rather large administrative burden, but also lately just has not been
working right (problems subscribing, duplicate emails, a continuous stream
of bounces, etc.). The list would go back to the way it used to be - one
list, one view, at classiccmp at classiccmp.org.
The primary reason for the "two view" paradigm was due to (at the time) some
very substantial off-topicness, flamewars, etc. For a period of time I was
not regularly reading the list and thus missed those things when they were
occurring. For the past year or so (and it will very likely continue that
way) I have been back to regularly watching/reading the list - so on my part
I will do a better job monitoring the list for "outbreaks", and will email
the involved parties off-list whenever (if) it starts to occur. In addition,
many of the most vocal flamers are no longer here. Separately, those who are
more irked by off-topicness I would ask to get slightly more familiar with
the DEL key J
Best,
J
From: Dave G4UGM
Sent: Tuesday, June 30, 2015 8:43 AM
>> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Toby Thain
>> Sent: 30 June 2015 14:10
>> On 2015-06-30 4:44 AM, simon wrote:
>>> On 29-06-15 14:56, Toby Thain wrote:
>>>> On 2015-06-29 3:54 AM, simon wrote:
>>>>> the front of the internal bus options maintenance manual in front of me.
>>>>> But looking at the f in 8/f gives me the impression they mixed some
>>>>> fonts for the logo and taking a closer look at the line:
>>>>> "digital equipment corporation . maynard. massachusetts"
>>>>> is proving both of us wrong. the y in maynard is a rounded version,
>>>>> but both futura and avant garde hve a straight y.
>>>>> "...the search continues..."
>>>> Can you scan the page you're looking at?
>>> tada.wav: https://hack42.nl/mediawiki/images/a/a7/Dec_footer.png
>>> it is also used on the front of the pdp8/f here at our museum.
> If it?s the oldest logo why do Straight Eights have a serifed font...
> http://dustyoldcomputers.com/pdp8/images-3C8F62C8/R3378-hp.jpghttp://archive.computerhistory.org/resources/text/DEC/pdp-1/DEC.pdp_1.1960.…
This early brochure for the PDP-1 features the vertical d
e
c
logo in a picture, as well as a serif face for titles and *on the machine*.
Our PDP-7 likewise has a serif face for "Digital Equipment Corporation" on its
name plate, with an outline block sans-serif "PDP-7". A brief survey of the
manuals for the 18-bit systems on Bitsavers shows that the change from a serif
face for titles occurred during the development of the PDP-7 documentation:
The preliminary edition of the User Handbook has the system name in a block
serif typeface, while the release edition has the name in a block sans-serif.
The PDP-6 (36-bit system) also uses the serif face; the PDP-8 is schizophrenic,
and the PDP-9 et seq. use sans-serif.
Note that I use the terms (type)face and logo, not "font". Until Apple
bastardized the term, a _font_ was a package of metal type in a particular
_typeface_, and was the unit by which type was ordered from a foundry. A
_logo_ was a special item, cast as a single unit for printing, not a collection
of individual pieces of type.
Someone in this thread mentioned having been in the graphics design trade, and
can certainly back me up on this, as well as on the fact that advertising
houses and departments generally designed their own lettering for lithographic
reproduction rather than using commercially available typefaces; the latter
were used for printed materials consisting of large stretches of text rather
than one-offs. (A company might adopt a face, or commission one, as part of
the house identity, in which case the lettering done by the graphics people
would probably resemble the face, but it's unlikely that it would be cast at
the large sizes needed for advertising, since each size requires a set of steel
punches to be engraved and a set of matrices to be produced.)
Rich
Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134
mailto:RichA at LivingComputerMuseum.orghttp://www.LivingComputerMuseum.org/
Hi Guys
I'm just about done sending first batch front panels
Needless to say I have had some feed back on reqirements.
As well as the variations of 8/e panels, 8/f 8/i 8/L and 8/m have
been mentioned.
;
Of these the 8/f seemed like a good place to start. I have the white
border and DEC logo in place.
When it came to the address an interesting issue arose.
DEC used their own font, It can be identified like this
The letter a is formed by a circle with a vertical bar on the right hand
side.
This font is used for titles and the like in handbooks of this period.
I'm going to have go at building this font as a nornal windows font and
adding it those available on windows.
If anybody has aready done this I'd like to hear from them.
I'm on holiday from 25-JUN-2015 to 2-JUL-2015.
We go to the big Ham Radio meeting in Friedrichshafen every year.
I should be able to do email but not much else
Finally I am in need of the following cards for my 8/e
-- M8330 - KK8E Timing board (system clock)
-- M8340 \_ optional KE8E EAE board 1
-- M8341 / optional KE8E EAE board 2
xx M8310 \_ KK8E CPU control (/I already have this/)
-- M8300 / KK8E CPU registers
-- M837 - KM8E or MC8E extended Memory & Time Share control
Can I get a basic system up without the 8340/41 and the M837?
If yes then I just need the M8330 AND M8300
_Can you help bring my 8/e back to life?_
Rod Smallwood
I have a rather long list of enhancements to the classiccmp website that I'd
like to make, and IANAWD (I am not a web developer).
In the past I have always had one of the staff web developers here make
minor changes around the edges, but my list of enhancements is now "bigger
than that". Are there any experienced web developers on the list that have
some free time (*chuckle*) and would like to contribute some time to the
hobby? I'd rather a fellow hobbyist work on this as a labor of love than one
of my web developers who really doesn't "get it". I may be able to put
together a few clams to help entice.
If there's any interest, please contact me off-list.
Best,
J
A gentleman in Miami Springs, FL emailed me and has the following available:
Two DEC H960 cabinets with headers & side panels containing the below
11/34 cpu
Three RL01/RL02 drives (picture seems to show 1 rl02 and 2 rl01?s, can?t be
sure)
TE10W ? mag tape drive
Full library of RSXM manuals
Spare 11/34 cpu
Spare power supply
?Many spare circuit boards, disks, and tapes?
Two VT100 terminals
Two LP11-VA line printers
?Single owner, known to be working?
Owner is asking $600, does not want to pack/ship
If interested, email me off-list and I?ll get you contact information.
Please, only people that are serious about the system and are able to pick
it up safely.
Best,
J