25 Mar
2006
25 Mar
'06
7:44 p.m.
134.5 baud was the exact baud rate required to match the motor speed of the
main shaft in the selectric mechanism. At that speed, the printer main
shaft clutch would remain continuously engaged. At any other speed, the
mechanical wear would destroy the mechanism VERY quickly. Obviously, with
buffering and handshaking one could use a faster rate externally, but that
speed was essential at the mechanism level.
All selectric mechanisms, at the mechanism level, use tilt/rotate code. You
tilt the ball to select a row, and then rotate it to select a column, then
whack the paper through a ribbon (it's a mechanism that Tony Soprano would
love). That is simply how a selectric works, and any other code will
ultimately get converted into tilt/rotate before being applied to solenoids
in the mechanism.
25 Mar
25 Mar
9:07 p.m.
"Barry Watzman" <Watzman at neo.rr.com> wrote:
All selectric mechanisms, at the mechanism level, use
tilt/rotate code. You
tilt the ball to select a row, and then rotate it to select a column, then
whack the paper through a ribbon (it's a mechanism that Tony Soprano would
love). That is simply how a selectric works, and any other code will
ultimately get converted into tilt/rotate before being applied to solenoids
in the mechanism.
I believe that one of Don Lancaster's logic cookbooks shows how to
convert ASCII to tilt/rotate codes. Either that or some mid-late-70's
Radio Electronics article that also tells how to use surplus core
memory...
The one Selectric that I saw converted just used a bunch of solenoids
to whack the keys on a plain old keyboard.
Did any micro hobbyists actually succesfully use surplus core? I remember
it somewhat cheap (but not ridiculously cheap)
in the Meshna catalog etc. but never saw it being used. It is not
a trivial matter to time and calibrate all the drive and sense lines
especially when it's some random core plane and the first you ever
saw.
Tim.
9:28 p.m.
It's covered in the first ed. 1976 TV Typewriter Cookbook with green cover.
----- Original Message -----
From: "Tim Shoppa" <shoppa_classiccmp at trailing-edge.com>
To: <cctech at classiccmp.org>; <cctalk at classiccmp.org>
Sent: Saturday, March 25, 2006 3:07 PM
Subject: Re: Where have all the Selectrics gone?
"Barry Watzman" <Watzman at
neo.rr.com> wrote:
All selectric mechanisms, at the mechanism level,
use tilt/rotate code.
You
tilt the ball to select a row, and then rotate it to select a column,
then
whack the paper through a ribbon (it's a mechanism that Tony Soprano
would
love). That is simply how a selectric works, and any other code will
ultimately get converted into tilt/rotate before being applied to
solenoids
in the mechanism.
I believe that one of Don Lancaster's logic cookbooks shows how to
convert ASCII to tilt/rotate codes. Either that or some mid-late-70's
Radio Electronics article that also tells how to use surplus core
memory...
The one Selectric that I saw converted just used a bunch of solenoids
to whack the keys on a plain old keyboard.
Did any micro hobbyists actually succesfully use surplus core? I remember
it somewhat cheap (but not ridiculously cheap)
in the Meshna catalog etc. but never saw it being used. It is not
a trivial matter to time and calibrate all the drive and sense lines
especially when it's some random core plane and the first you ever
saw.
Tim.
9:35 p.m.
On Saturday 25 March 2006 04:28 pm, Keys wrote:
It's covered in the first ed. 1976 TV Typewriter
Cookbook with green cover.
Ah. I have that one, but it's been a *long* time since I looked at it. :-)
Also cheap video, and son of...
----- Original Message -----
From: "Tim Shoppa" <shoppa_classiccmp at trailing-edge.com>
To: <cctech at classiccmp.org>; <cctalk at classiccmp.org>
Sent: Saturday, March 25, 2006 3:07 PM
Subject: Re: Where have all the Selectrics gone?
> "Barry Watzman" <Watzman at neo.rr.com> wrote:
>> All selectric mechanisms, at the mechanism level, use tilt/rotate code.
>> You
>> tilt the ball to select a row, and then rotate it to select a column,
>> then
>> whack the paper through a ribbon (it's a mechanism that Tony Soprano
>> would
>> love). That is simply how a selectric works, and any other code will
>> ultimately get converted into tilt/rotate before being applied to
>> solenoids
>> in the mechanism.
>
> I believe that one of Don Lancaster's logic cookbooks shows how to
> convert ASCII to tilt/rotate codes. Either that or some mid-late-70's
> Radio Electronics article that also tells how to use surplus core
> memory...
>
> The one Selectric that I saw converted just used a bunch of solenoids
> to whack the keys on a plain old keyboard.
>
> Did any micro hobbyists actually succesfully use surplus core? I remember
> it somewhat cheap (but not ridiculously cheap)
> in the Meshna catalog etc. but never saw it being used. It is not
> a trivial matter to time and calibrate all the drive and sense lines
> especially when it's some random core plane and the first you ever
> saw.
>
> Tim.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
9:32 p.m.
On Saturday 25 March 2006 04:07 pm, Tim Shoppa wrote:
"Barry Watzman" <Watzman at
neo.rr.com> wrote:
I remember him doing something with converting either to or from Baudot code
(5-level), but not selectric...
Of course, I still don't have a copy of the RTL cookbook, and I suppose it
could be in there. :-)
All selectric mechanisms, at the mechanism level,
use tilt/rotate code.
You tilt the ball to select a row, and then rotate it to select a column,
then whack the paper through a ribbon (it's a mechanism that Tony Soprano
would love). That is simply how a selectric works, and any other code
will ultimately get converted into tilt/rotate before being applied to
solenoids in the mechanism.
I believe that one of Don Lancaster's logic cookbooks shows how to
convert ASCII to tilt/rotate codes. Either that or some mid-late-70's
Radio Electronics article that also tells how to use surplus core
memory... The one Selectric that I saw converted just used a
bunch of solenoids
to whack the keys on a plain old keyboard.
I remember some outfit selling those way back when.
Did any micro hobbyists actually succesfully use
surplus core? I remember
it somewhat cheap (but not ridiculously cheap)
in the Meshna catalog etc. but never saw it being used. It is not
a trivial matter to time and calibrate all the drive and sense lines
especially when it's some random core plane and the first you ever
saw.
I never really thought of actually using one, but thought that it might be
kind of neat to have one of those to hang on the wall. :-) And yeah, I
remember those Meshna catalogs too.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin
9:32 p.m.
On 3/25/2006 at 4:07 PM shoppa_classiccmp at trailing-edge.com wrote:
Did any micro hobbyists actually succesfully use
surplus core? I remember
it somewhat cheap (but not ridiculously cheap)
in the Meshna catalog etc. but never saw it being used. It is not
a trivial matter to time and calibrate all the drive and sense lines
especially when it's some random core plane and the first you ever
saw.
There was an article way back in one of the hobbyist mags (Microsystems,
Kilobaud???) about a guy who did adapt a core module to his S-100 box.
Note that it was a "module"--essentially a box with the core and all of the
drivers, sense amps, latches and rewrite circuitry inside. Mostly a job of
interfacing and supplying power.
Cheers,
Chuck
6926
days inactive
6926
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