>::> If we began to discuss the agents that can *actually* destroy data
>::> on floppies
>::
>::I find that scissors work well.
>
>Two words: paper shredder.
Microwave oven - haven't actually tried it but does wonders for CD's
Chuck
cswiger(a)widomaker.com
Several times in the past I've seen home-brewed and perhaps
CPU-driven signs that consist of a single vertical line of
perhaps a dozen or two LEDs.
The "sign" doesn't appear to be anything but a line of glowing LEDs.
Only when you view it at a glance, as your vision moves quickly
>from side-to-side, do you see that it is rapidly flickering the
vertical scanlines of a simple dot-matrix image: maybe the digits
of the time, perhaps a smiley face, or some other simple image.
Anyone here know the name of this sort of device, so I can web-search
for others who've made one? It wouldn't be hard to craft. To be
obliquely on-topic, I've thought about making a simple circuit that
would be driven by the parallel port of an old PC.
- John
List:
This may not fit the >10 year old criterion, but
just spotted an ad in a local trading paper
Sun workstation, 19" color monitor, works great $150 obo
details at 11
Chuck
cswiger(a)widomaker.com
I have recently obtained a machine that when carried resembles a sewing
machine in a carry case, marked Compaq Portable. It has a built in CRT
and is evidentally an 8088 or 8086 machine judging by the 8 bit slots.
Anyone have any info on it, and is there any collectability to these?
I'm in the process of cleaning and repairing it but I will inevitably
NOT keep it for myself due to space limits and am putting out feelers on
the list first for possible buyers/traders. I don't expect a lot out of
it, mostly what I have in it ($25) unless I have to put a lot of parts
or work into it, which I doubt since it appears to be semi-working at
the moment.
I'll probably put it on ePay around the 20th once I get it functional
and get no apparent responses.
Any info or prospects appreciated.
At 02:05 PM 11/12/98 -0800, you wrote:
>At 05:23 PM 11/12/98, you wrote:
>> There was also a Portable III. I have five of them!! They're a little
>>larger than a lunch box and have a 12 MHz 286 CPU and a fold out gas plasma
>>screen. They have a place for a MODEM on an ISA card in the bottom of the
>>case. And a place for a memory expansion card that held up to six SIMMs.
>>The SIMMS that were available were 256K or 1 meg so you could have up to 6
>>Megs & 640K of memory. There was an option to add a box on the back that
>>contained an 8 bit and a 16 bit ISA slots. Mine have the box with the ISA
>>card slots and I use them for portable instrument controllers.
>
>Did they market a Portable III to 386 upgrade kit? I've got a Portable III
>with a 386-20 (well, now a 486slc-40) in it, but it still has the III on
>the case and the XT-style keyboard.
I'm not aware of a 386 or 486 upgrade kit, but They use a weird board in
them so if your's has a 386 then it almost certainly had to have come from
Compaq. BTW the PIII came with two different styles of keyboards.
Joe
>> And dust particles will work like sandpaper and grind the
>> disk surface
> Which is why the inside of the disk jacket has material to sweep up
> dust and keep it from the disk surface.
Sometimes this works.
> Geez, people, I never claimed that you could dump huge piles of dust, smoke,
> dirt, and sand on the floppy disk and expect it to work for more than five
> seconds. My point was that you don't have to be super-careful with them. One
> dust particle isn't going to ruin the disk (at least not very quickly). You
> don't have to handle floppy media in a cleanroom. However, one dust or smoke
> particle *IS* enough to cause a head crash in a Winchester drive.
I have even seen SyJet drives working within a heavy
smokers environment - a friend of mine - he has ashes
all around the desk, the keyboard and everywhere else.
And the dam things are working prety good.
> > there are 4 basic technologies for the head/surface
> > management of disk Magnetic:
> >
> > 1. Fixed head over hard surface
> > 2. Flying head over fixed surface (Winchester)
> > 3. Fixed head over flexible surface (Bernulli)
> > 4. Head grinding over flexible surface (Floppy)
> > (also tapes go into #4 but since the head surface
> > speed is only slow, the effekt is less visible)
> Depends on the kind of tape. Helical scan tape has this effect
> *MORE* than floppy drives, because the head-to-tape speed is much
> higher.
:))) to modern in data processing - I'll ignore them.
Any tape with more than 1600 dpi isn't a tape to me :)
>> And we are talking about 2 vs. 4 (head flying over hard
>> surface vs. head on flexible surface). The other ones
>> have been used in several drive types thru the past. And
>> all in encapsulated (seled) and 'free' environment.
> That's my point. The Syquest SyJet and Sparq drives, and the Iomgea
> Jaz drive, appear to use what you have listed as configuration 2.
> They have to, in order to get .75 to 1.0G density per platter.
> Configuration 1 can't get the head close enough to the media. And even
> if they did use configuration 1 and get the head close enough to the
> media, then it would be just as susceptible to foreign particles as
> configuration 2.
They used #2 in the SyJet, since the problems are much
bigger with #1. My experiance with any kind of high
density media is that the process of insert and remove
has to be done in a aprobiate manner. Like back in my
operator times, the insertation of a Disk has just to
be done carefuly and sensitive. And this is still true
for any other modern removable media.
> That's precisely why they are so f*&#ing unreliable.
I just cant agree - I have several running without any
problem. As I mentioned earler, I have almost any drive
ever build from Syquest (and some other manufacturers),
and I'm prety satisfied with Syquests.
The only thin I learned to hate are MO drives. Once I
had a 640 MB Sony drive, and it died 5 times and had to
be replaced 5 times ... Later on I went back to pure
magnetics.
> Out of over 30 SyJet and Sparq drives, I don't think we've had a single
> one last more than 100 cartridge insert/eject cycles.
I son't know whats wrong, but I may just have had luck.
Servus
Hasn
--
Ich denke, also bin ich, also gut
HRK
Hi,
I haven't heard of a "Calcomp", but CompuCorp also made a line
of desktop calculators (also marketed by Monroe, Dietzgen, and
possibly others) that were offered in the early-mid 70's that
had an optional punch-card reader that you plug into the
back of the machine. I just obtained several of those card
readers, cards, and the card holder & stylus (which are much
like you described) and hope to have some photos of this
stuff on my Web site soon. The CompuCorp calculators were
designed such that you _had_ to use the punch-card reader to
access all of the programming functions - while the machines
were keyboard-programmable there were a lot of program codes
that couldn't be entered directly from the keyboard.
Also, so far I'm not aware of any CompuCorp desktop machines
that had both display and printer as you describe. The Monroe
1655 that's on my Web page (also sold by CompuCorp as their model
122) is a nixie machine, and the 1765 I'm getting is a printing-
only machine (with special surveyor's functions) with what looks
to be a 16-column impact printer.
Regards,
Alex
Calculator History & Technology Archive Web Page
http://aknight.home.mindspring.com/calc.htm
At 10:05 AM 11/13/98 -0500, Chuck wrote:
>Hi Alex;
>
> Interesting site. I'm curious if you (or anyone else here) has
>heard of a programmable calculator by, I beleive' "Calcomp". We had one
>in high school in mid 70's - it came with an integrated printer, probably
>about 40 columns, can't recall what the display was, maybe blue
>flourescent, - and the interesting thing is you could program it with
>punch cards. Once you code something, you put a card into a hand
>held card punch holder that was a rubber backing with slots beneath
>all the holes, and use a stylus to punch out the holes. Then you could
>program it by feeding the cards into a little motorized reader plugged
>into the Calcomp.
>
> That was my first programming experience which led to a lust
>for Mark-8's and Altairs, etc.
>
> Chuck
> cswiger(a)widomaker.com
>
>
>
From: Doug Yowza[SMTP:yowza@yowza.com]
Subject: Re: FREE DG Nova Stuff
>> I was scanning the web during lunch, and I came across a most
>> interesting entry. Check this out...
>>
>> http://www.hopco.com/surplus/s_free.htm
>
>I tried to move quickly given that collectible-computer dealers are known
>to lurk and strike based on these tips. Alas:
>
><<
>Unfortunately, you're a couple months late :( I've got to find time to
>update that list and remove that stuff. This represented 20+years of
Doh! Hopefully you at least educated them to spread the word
about where to go with such dumpster gems like that next time?
Once upon a time - while a field droid for NCR we used to maintain
stuff based on their '605' mini-computer and had one in the shop
to copy tapes and test boards (One of my grocery stores still used
one with do-nut core memory in mid '85). Suddenly we got a new
manager, suddenly the 605 was unceremoniously tossed into the
dumpster. Any one of 5 or 7 techs would have gladly taken it
home to their garage but nooooo, it was given an indecent burial
in the name of 'fairness'.
sniff-sniff
Chuck
cswiger(a)widomaker.com
> I wrote about the problems with "modern" removable-rigid-media drives:
>>> Air filters? Ha! They have nothing but a shutter on the cartridge and a
>>> door flap on the drive. Absolute rubbish. It's miraculous that they work
>>> even for a few weeks.
> "Hans Franke" <franke(a)sbs.de> wrote:
>> Dame has been said on 8" FD: These will be damaged within hours
> Same?
> No, no one with a grasp of how the technology works has ever claimed that a
> little dust or smoke will damage a floppy disk or drive. Floppy disks use a
> much different head/media interface than winchester rigid-media drives. Dust
> or smoke particles can and will cause head crashes on winchester drives.
And dust particles will work like sandpaper and grind the
disk surface (we have a nice wording in German for that:
FD are 'Spanabhebende Datenverarbeitung'. Datenverarbeitung
means data provessing and spanabhebend is the term for a
metal forming process thru producing fillings with using
cutting tools like on a lathe :). Any material will degenerate
the surface - and even in clean room condition, the head
itself grinds the magnetic surface away.
> I am not a technical expert on the innards of Iomega Jaz and Syquest SyJet
> and Sparq drives. However, a casual examination suggests that they use
> winchester technology. This is consistent with the manufacturers descriptions
> of the drives in product literature, and it is also consistent with the
> high failure rate I've observed (approaching 100% after four weeks on the
> Syquest drives). Winchester drive technology was developed for permanently
> sealed HDAs, not cartridge drives. And even the sealed drives were designed
> with air filtration.
Maybe to clear some things:
We are not talking about 'Winchester' technology
there are 4 basic technologies for the head/surface
management of disk Magnetic:
1. Fixed head over hard surface
2. Flying head over fixed surface (Winchester)
3. Fixed head over flexible surface (Bernulli)
4. Head grinding over flexible surface (Floppy)
(also tapes go into #4 but since the head surface
speed is only slow, the effekt is less visible)
And we are talking about 2 vs. 4 (head flying over hard
surface vs. head on flexible surface). The other ones
have been used in several drive types thru the past. And
all in encapsulated (seled) and 'free' environment.
Before there where capsulated 'Winchester' type drives
mainframes relied on removable disk stacks wit technology
#1. Of course these had air filtration etc., but the stacks
itself have not been encapsulated at all time, especialy not
air tight.
The old Syquest 44s (and following) are using this technology
(number 1), like back in the 60s to 80s on mainframes. The
head surface distance is basicly fixed by the drive mechanic,
althrough modern drives of this kind have some sort of control
to adjust it.
> Someone pointed out that he'd had no trouble with Syquest 230M drives; I've
> personally had reasonable results with their earlier 44M and 88M 5.25 inch
> drives. I don't what differences between the lower and higher capacity
> drives accounts for the huge difference in reliability.
I have used (and still use) the 44/88 drives over years without
any failiure. the same with the 3 1/2" drives, So I've no reason
to fight - instead I'm very sad that Syquest fades away.
Gruss
hans
--
Ich denke, also bin ich, also gut
HRK
Now moving the topic from Zip drives to RK05's:
In an earlier message Hans Franke wrote:
>> You mean they _don't_ haev the proper air filters? Ouch. High density
>> media needs a cleaner environment than the old RK05 units, and those have
>> pretty serious filters in them.
Well they (RK05's) don't use them much...
I did service on a pair of RK05's in a Tektronics chip test unit that
were installed and running (and under DEC Service) with the filters still
CAPPED by the idiot who was the service tech there before me.
(I was the next idiot, I don't know who Compaq's got as the current idiot.)
8-)
They were still working 6 months to a year after the capped filter install
which was probably the PM prior to my arrival on site.
The RK05's were running VERY hot, but still running without errors
(even under diags).
Man, you couldn't kill those RK05's. I hit a head with a 1/4 inch
bend on a disk and it kept running after I scraped the head with
a penknife and alcohol to remove the scarred oxide.
They flew those heads at about 10000 feet compared to the current
disks.
Now, 9766's (RM05's) flew a lot closer (even with the DEC high
altitude heads installed). They needed to be kept clean.
RP06's were less touchy and RM03's were just a nightmare.
Give me tape drives (even TS11's and Tu45's) to work on over disks
anytime. They don't get you up at 3am for a tape head crash.
Bill
