> Redactron dual mag card WP (with one card), schematic, no
> printer. Can I assume there's no interest and I can finally
> toss something without feeling guilty?
and
>One gone, one awaiting its fate: T300 dual floppy PC semi-compatible, no
monitor (but std >RGB OK), spare KB, 2 sets of 3 manuals, 123 & dBII,
diskettes & some tech info; also >service info & schematics for T100. Good
for converting 360 to/from 600 Kb diskettes.
Hi,
If there are no other (or nearer) takers for
these items, could I have the tech manuals
and schematics (and maybe diskettes?). I'll scan them if
there is sufficient interest.
Obviously I'll pay for shipping (surface mail).
I'm in the UK otherwise I'd be interested in the hw too!
Thanks
Antonio carlini
arcarlini(a)iee.org
Can anyone point me to a scan of the DEC TC01 tape controller? This is the
early dectape controller used with very early PDP8 machines at least.
Kevin Murrell
-------------
> I am pretty sure TI published a datasheet on the chip. It
> gave at least
> the pinout and the pin functions, it may have included the
> instruction
> set. I may hae some data on the chip in old TI databooks, I can check.
The only reference within TI's own site (that
I can find) is that the chip debuted in 1974.
freetradezone has a two page sheet which
has little technical information. It does say
that software simulators were available for
customer use as were hardware simulators.
Antonio
> I have a card in my 512 which increases memory and gives a SCSI port.
> It's called a MacSnap by Dove computer, dated 1985. It actually consists of
> 2 cards. One contains the memory chips aand circuitry and the other has
> the SCSI socket and also 2 large chips labelled upper and lower ROMs. I'm
> even able to boot off the external HDD.
Great product, I used mine with a Cutting Edge 30MB external drive
until the drive's piggyback OMTI SCSI <=> MFM adapter went south.
Anyone know where I can get one of these tiny adapters?
-dq
On October 15, Tony Duell wrote:
> > > Ahh, the 74LS181s are ALUs, as is the 'F582. Interesting that they
> > >used both. I'm curious...what kind of processor is this?
> >
> > Am I the only one who finds it a bit perverse that there are 74xxx standa=
> > rd
> > TTL circuits for such complex functions as ALUs? I thought that the way t=
>
> Actually, what suprises me is how _simple_ the 74181 gate schematic is
> (it's published in most TTL databooks). It doesn't take that long to
> understand how it works.
>
> In terms of the transistor count, I suspect there are TTL chips which are
> more complex than the '181.
The '181 is even used in the pdp11/04 and /34 if memory serves.
Anyone know of any others?
-Dave
--
Dave McGuire
Laurel, MD
I purchased a plastic bag mixed with new and used 5 1/4 floppy diskettes
and inside the middle was one of the famous "Fileware" or Twiggy
diskettes with it's sleeve used with the Lisa I. I could not believe
my luck as I had just watched one of these go for almost $50 dollars on
eBay for just one diskette awhile back. Now I just need to find a
twiggy drive or better yet a Lisa I. :-) Yes I went back to the
thrift store looking for more disk but no luck. The cost of the package
was $1.40 for about 20 diskettes.
>When I installed PhoneNet stuff into my mother's all-Mac shop, it
>specifically uses the yellow-black pair of standard (US) phone
>wiring and the documentation explicitly shows it as such. They
>even had a sort-of passive hub for your wiring closet to collate
>all the black-yellow pairs for a larger (floor-sized as opposed to
>room-sized) network. We had six Macs and one LaserWriter on the same
>floor of a smallish retail establishment, so it wasn't a problem.
>I can see networks near the edge of their physical spec falling off
>a cliff, though.
Yeah, phone net was designed with the idea that you would piggy back it
over your existing phone wiring... the theory being that a standard
house/business would be wired either all serial (one jack to the next) or
in a star (all jacks coming back to a central punch block). Following
this assumption, it was specifically designed to work over the unused
pair (being yellow/black in standard station wiring).
All PhoneNet REALLY cares about is having two wires from one box to
either the next box, or to a central hub. It need not be twisted pair,
and it need not be the yellow/black pair. Although, if you choose to use
a different pair, either you need to make sure you wire it to the correct
pins on the jack (and thus fake a y/b) or you will have to cut a custom
wired flat cord as the boxes all expect the wires to be the outer two
wires in an RJ-11. But there is nothing stopping you from using unused
pairs in Ethernet and just use a custom flat cord (or break them out into
their own jack).
The single biggest problem with Phone net that I ran into was it was VERY
picky over the wiring being correct. Unlike phones, you could not safely
reverse pairs in a serial setup. Also, the fact that it expects there to
be either serial wiring, or star wiring falls thru in most phone lines.
And even depending on the unused pairs wasn't a surefire idea. In every
Phone net system I installed, I was forced to do some degree of rewiring,
or correcting the wiring. POTS phones are very forgiving to poor wiring,
and many telco installers use that as an excuse to be lazy. In almost all
POTS phone setups you will find some degree of "non spec", things like
unused pairs not being connected, reversing pairs, mixing star and serial
wiring, tapping mid line into a drop to extend for a new jack. Tapping
was DEATH to phone net, it was the single worst thing you could do, as it
caused things like ghosting (items showing up after they have been
removed, or showing up more than once on the network), and random
dropouts of networked devices. It also proved hard to track, as you
almost had to physically trace every wire, looking for a tap.
But all things considered, phone net was a much more econimical way of
wiring a localtalk network. True localtalk cables were very expensive
compared to cheap 2 pair phone cable, so even with rewiring, it still
worked out to be the less expensive way to go.
Even today, phone net works as a nice quick and dirty network when all
you want is printer sharing. I keep a 25ft retractable cord and phonenet
connectors connected to a Localtalk to Ethernet bridge. It lets me
connect old Macs to the network (or my Newton) on the fly, and I can set
it up anywhere in my office. When I am done, I just unhook the phonenet
box, and let go, the retractable cord rewinds and pulls the box back to
my hub shelf, where it hangs waiting for my next use.
-chris
<http://www.mythtech.net>
> BUT... predating that was a "Macintosh Hard Disk 20" that was not scsi.
> Rather is was some drive (don't know what kind, but MFM seems sensible
> enough) that used a special adaptor board that enabled it to plug into
> the disk drive port on a bunch of the older macs. It was all enclosed
> (drive, power supply, adaptor board) in one nice zero footprint beige
> case (back when beige meant brown, and not grey like "beige" computers of
> today).
In spite of the now long-extant senility, I seem to recall that these
interfaces through the serial port, not the floppy port.
Regards,
-dq
On October 16, Gene Buckle wrote:
> > According to at least one movie I watched the part that is critical are
> > some special triacs so that each charge can be detonated within a fairly
> > tight time window.
>
> Klystron(?) I might be wrong though. I keep thinking it begins with a
> "K". For the gun type, all bets are off - it's a _much_ simpler design.
That would be "krytron". A Klystron is a microwave oscillator tube.
-Dave
--
Dave McGuire
Laurel, MD
