On 01/15/2014 08:03 PM, Gregg Levine wrote:
I think they still make dot matrix ones for those applications that
only a printer like that would do. Which includes financials and real
estate and possible insurance.
Yes, dot matrix printers are still being manufactured. Their primary
use is for multi-part forms. One I've seen recently (last week) is an
Okidata Microline 320, with a USB interface, at a truck rental company.
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
Hello!
Reminds me of how in our Apple days, my brother participated in a
course for computers in school. Naturally the others needed to wait
until after school, or worse the next day to do their homework. Jay
did his on ours. And had our new Epson MX100 printer print-out a fancy
banner for it. That printer worked its way past several systems. And
according to Epson they stopped making print heads for it, (alone)
before someone stopped making ribbons.
I think they still make dot matrix ones for those applications that
only a printer like that would do. Which includes financials and real
estate and possible insurance.
-----
Gregg C Levine gregg.drwho8 at gmail.com
"This signature fought the Time Wars, time and again."
On Wed, Jan 15, 2014 at 7:32 PM, Cory Smelosky <b4 at gewt.net> wrote:
On Wed, 15 Jan 2014, Dave McGuire wrote:
On 01/15/2014 07:20 PM, Johnny Billquist wrote:
Heh! The DZ-11 is a hog. We all know that.
But the LP11 is not really much better. It's also interrupt per
character unless I remember wrong. But it's only one printer per card,
and no input. And of course, much faster, since it's parallel with
handshaking.
The Unibus controller I used at work, and later at home, with an LA180
was an LS11. I don't remember if it was interrupt-per-character as
well, but since it was fairly non-dense TTL logic, I'd assume it was.
It fared very well on my 11/34 running (at the time) RSX. In the
mid-1980s, I was the first person to turn in high-school homework on
printer paper. Even some of the teachers were asking what kind of
"typewriter" made such "strange-looking print". ;)
You've reminded me of how I was the only person a teacher knew who did a
science project narrated by Microsoft Sam.
-Dave
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On Wed, 15 Jan 2014, Dave McGuire wrote:
On 01/15/2014 07:20 PM, Johnny Billquist wrote:
Heh! The DZ-11 is a hog. We all know that.
But the LP11 is not really much better. It's also interrupt per
character unless I remember wrong. But it's only one printer per card,
and no input. And of course, much faster, since it's parallel with
handshaking.
The Unibus controller I used at work, and later at home, with an LA180
was an LS11. I don't remember if it was interrupt-per-character as
well, but since it was fairly non-dense TTL logic, I'd assume it was.
It fared very well on my 11/34 running (at the time) RSX. In the
mid-1980s, I was the first person to turn in high-school homework on
printer paper. Even some of the teachers were asking what kind of
"typewriter" made such "strange-looking print". ;)
You've reminded me of how I was the only person a teacher knew who did a science project narrated by Microsoft Sam.
-Dave
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
On 01/15/2014 07:20 PM, Johnny Billquist wrote:
Heh! The DZ-11 is a hog. We all know that.
But the LP11 is not really much better. It's also interrupt per
character unless I remember wrong. But it's only one printer per card,
and no input. And of course, much faster, since it's parallel with
handshaking.
The Unibus controller I used at work, and later at home, with an LA180
was an LS11. I don't remember if it was interrupt-per-character as
well, but since it was fairly non-dense TTL logic, I'd assume it was.
It fared very well on my 11/34 running (at the time) RSX. In the
mid-1980s, I was the first person to turn in high-school homework on
printer paper. Even some of the teachers were asking what kind of
"typewriter" made such "strange-looking print". ;)
-Dave
--
Dave McGuire, AK4HZ
New Kensington, PA
On 2014-01-15 15:42, Cory Smelosky wrote:
On Wed, 15 Jan 2014, Dave McGuire wrote:
On 01/15/2014 06:35 PM, Cory Smelosky wrote:
A lot of people (myself included) insisted on direct-in-the-bus
printer controllers when we saw how badly serial printers tanked the
system when we connected them to DZ11s. ;)
Oh I can imagine that. A dedicated controller would have MUCH higher
bandwidth than the <1.5mbitcapable on the DZ11. ;)
It's the interrupt load that's the problem. It could TANK an 11/750.
Didn't the DZ11 depend on the CPU for interrupts?
Eh... Every controller depends on the CPU for interrupts. That's what interrupts mean.
However, the problem with the DZ11 is that it generates interrupts for each character sent as well as each character received. It do have some smart in it, so you can get a few characters per interrupt under some circumstances, but the interface basically just killed a machine when you did lots of I/O, because of the interrupt load.
Isn't that why say...the DHV11 had processors to offload serial
processing to?
DH11, DHV11 and DHU11 all use DMA for output, meaning you only get one interrupt when the output is done. Which is *way* better.
Johnny
On 2014-01-15 15:31, Dave McGuire wrote:
On 01/15/2014 06:27 PM, Cory Smelosky wrote:
The LA180 has more in common with the LA120 than the LA36. There is
also a serially-interfaced variant of the LA180, which has a
serial-to-parallel (*NOT* "Centronics" parallel, for others reading
this) converter board mounted internally.
That's...quite interesting. Why is it parallel internally...
Because the primary intended configuration for those printers is with
dedicated printer controller boards like the LP11, LPV11, and LS11.
Ahhhhh. Interesting design choice, to be honest. I bet it was a bit
proprietary though....fast as well.
Of course it's proprietary. You ordered a printer from DEC when you
ordered your computer from DEC. It was a very different world back then.
A lot of people (myself included) insisted on direct-in-the-bus
printer controllers when we saw how badly serial printers tanked the
system when we connected them to DZ11s. ;)
Heh! The DZ-11 is a hog. We all know that.
But the LP11 is not really much better. It's also interrupt per character unless I remember wrong. But it's only one printer per card, and no input. And of course, much faster, since it's parallel with handshaking.
Johnny
On 2014-01-15 15:28, Brian Schenkenberger, VAXman- wrote:
The LA120 was the de facto console terminal for the VAX-11/78*s. One reason
why I have three; albeit, one has been cannibalized for parts.
Also standard on PDP-11s as well as DECsystem-10 and DECsystem-20 machines...
Update have at least three... (Or had, last I looked. Two with 20mA and one with RS-232.)
Johnny
On 2014-01-15 15:27, Cory Smelosky wrote:
On Wed, 15 Jan 2014, Dave McGuire wrote:
On 01/15/2014 06:00 PM, Cory Smelosky wrote:
The LA180 receive-only printer was, I think, a derivative of the
LA36, not the LA120. The 1976 Peripheral handbook seems to support
that. Note that there also was an LA35, a receive-only variant of
the LA36. The difference is that the LA35 had a serial interface
while the LA180 had a parallel (line printer style) interface.
The LA180 has more in common with the LA120 than the LA36. There is
also a serially-interfaced variant of the LA180, which has a
serial-to-parallel (*NOT* "Centronics" parallel, for others reading
this) converter board mounted internally.
That's...quite interesting. Why is it parallel internally...
Because the primary intended configuration for those printers is with
dedicated printer controller boards like the LP11, LPV11, and LS11.
Ahhhhh. Interesting design choice, to be honest. I bet it was a bit
proprietary though....fast as well.
The interface on the LP11 is extremely close to Centronics. You need to invert a signal or two (I don't remember the details, but I did this many years ago for an LP8 controller). After that, you're all set.
It's much faster than serial, but no speed daemon.
Johnny
On 2014-01-15 15:17, Brian Schenkenberger, VAXman- wrote:
Mark Wickens <mark at wickensonline.co.uk> writes:
So, out of interest, what was the last/most reliable/most desirable DEC
true line printer - i.e. chain/band rather than matrix?
My first year at college ~ 1990 included VAX/Pascal programming with
assignments printed to a true line printer.
Happy times in that lovely warm computer room on cold, dark winter days...
IMHO, the LXY21!
Never used that one, but my experience with the LP26 and LP27 are good. I never had any problems with them. Never had problems with the LP14 either, as far as I can remember, but it was a beast.
Johnny
On Wed, 15 Jan 2014, Dave McGuire wrote:
On 01/15/2014 06:57 PM, Cory Smelosky wrote:
Note that these are larger-than-normal racks, and they're very
difficult to move. They weigh about 1200lbs. I've moved a pair of
these machines by myself without proper equipment, and thus at great
personal risk, to my old place a few years ago. I did so out of
necessity. The story (with pics) is here:
http://www.neurotica.com/wiki/Sun_Fire_6800_Unload
DO NOT TRY THIS AT HOME. I could very easily have gotten killed in
that operation. "Regular" racks are one thing...these weigh well over
half a ton, and are a different matter entirely.
Well, I'll stick it in the room where a piano used to sit. It should
hold there. ;) (Also no need for stairs, then.)
Measure the doorways. I have to rent special trucks to move 6800s due
to their height. If memory serves, they are 76" tall.
I think that would barely fit. Maybe i'll want to build a little shed for it. ;)
I could also fairly easily rig something up with a switch to change
between that and the oven, then...as nowhere else would I have minimum
30A service save for upstairs and the air conditioner. ;)
You'll have to do more than that. That machine has FOUR 230V 30A
power cables. It can run on two.
That would be a bit harder to manage. ;)
Getting to 230V is easy. Getting to 230V with 30A each is harder.
-Dave
--
Cory Smelosky
http://gewt.net Personal stuff
http://gimme-sympathy.org Projects
