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* [TUHS] CR delay for VT05
@ 2020-07-19 23:32 Richard Tobin
  2020-07-20  4:28 ` Random832
  2020-07-29 23:23 ` Dave Horsfall
  0 siblings, 2 replies; 6+ messages in thread
From: Richard Tobin @ 2020-07-19 23:32 UTC (permalink / raw)
  To: tuhs

Looking at the 6th edition man page tty(2), I see

     Carriage-return delay type 1 lasts about .08 seconds and is
     suitable for the Terminet 300.  Delay type 2 lasts about .16
     seconds and is suitable for the VT05 and the TI 700.  Delay
     type 3 is unimplemented and is 0.

     New-line delay type 1 is dependent on the current column and
     is tuned for Teletype model 37's.  Type 2 is useful for the
     VT05 and is about .10 seconds.  Type 3 is unimplemented and
     is 0.

Why would the VT05 (a VDU) need a delay for carriage return?
I can just about imagine that it might need one for linefeed
if it shifted the characters in memory.

-- Richard

-- 
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [TUHS] CR delay for VT05
  2020-07-19 23:32 [TUHS] CR delay for VT05 Richard Tobin
@ 2020-07-20  4:28 ` Random832
  2020-07-29 23:23 ` Dave Horsfall
  1 sibling, 0 replies; 6+ messages in thread
From: Random832 @ 2020-07-20  4:28 UTC (permalink / raw)
  To: TUHS

On Sun, Jul 19, 2020, at 19:32, Richard Tobin wrote:
> Looking at the 6th edition man page tty(2), I see
> 
>      Carriage-return delay type 1 lasts about .08 seconds and is
>      suitable for the Terminet 300.  Delay type 2 lasts about .16
>      seconds and is suitable for the VT05 and the TI 700.  Delay
>      type 3 is unimplemented and is 0.
> 
>      New-line delay type 1 is dependent on the current column and
>      is tuned for Teletype model 37's.  Type 2 is useful for the
>      VT05 and is about .10 seconds.  Type 3 is unimplemented and
>      is 0.
> 
> Why would the VT05 (a VDU) need a delay for carriage return?
> I can just about imagine that it might need one for linefeed
> if it shifted the characters in memory.

According to the VT05 manual, it only required a line feed delay [and other functions, most of which other than erase screen had in common that they moved or could move the cursor's vertical position] and only needed about .02 seconds ["slightly greater than one full cycle of the AC line", and the examples given were 1 character per 600 baud]

https://vt100.net/docs/vt05-rm/chapter2.html

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [TUHS] CR delay for VT05
  2020-07-19 23:32 [TUHS] CR delay for VT05 Richard Tobin
  2020-07-20  4:28 ` Random832
@ 2020-07-29 23:23 ` Dave Horsfall
  2020-07-30  0:56   ` Clem Cole
  2020-07-30 16:42   ` Paul Winalski
  1 sibling, 2 replies; 6+ messages in thread
From: Dave Horsfall @ 2020-07-29 23:23 UTC (permalink / raw)
  To: The Eunuchs Hysterical Society

On Mon, 20 Jul 2020, Richard Tobin wrote:

> Why would the VT05 (a VDU) need a delay for carriage return? I can just 
> about imagine that it might need one for linefeed if it shifted the 
> characters in memory.

Given that the VT05 (shudder!) is broken in so many others ways e.g. 20x72 
screen, sends upper-case only unless you flip an internal switch, etc, I'm 
not surprised that it would also need a CR delay...

Primitive firmware?

-- Dave

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [TUHS] CR delay for VT05
  2020-07-29 23:23 ` Dave Horsfall
@ 2020-07-30  0:56   ` Clem Cole
  2020-07-30 16:42   ` Paul Winalski
  1 sibling, 0 replies; 6+ messages in thread
From: Clem Cole @ 2020-07-30  0:56 UTC (permalink / raw)
  To: Dave Horsfall; +Cc: The Eunuchs Hysterical Society

[-- Attachment #1: Type: text/plain, Size: 731 bytes --]

You wish.  VT05 was designed in 71 - straight TTL, no microprocessor.  Same
for the VT-52.  First micro was an 8085A in the VT1XX
Prints are: http://www.pdp8.net/query_docs/query_all.html

On Wed, Jul 29, 2020 at 7:25 PM Dave Horsfall <dave@horsfall.org> wrote:

> On Mon, 20 Jul 2020, Richard Tobin wrote:
>
> > Why would the VT05 (a VDU) need a delay for carriage return? I can just
> > about imagine that it might need one for linefeed if it shifted the
> > characters in memory.
>
> Given that the VT05 (shudder!) is broken in so many others ways e.g. 20x72
> screen, sends upper-case only unless you flip an internal switch, etc, I'm
> not surprised that it would also need a CR delay...
>
> Primitive firmware?
>
> -- Dave
>

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [TUHS] CR delay for VT05
  2020-07-29 23:23 ` Dave Horsfall
  2020-07-30  0:56   ` Clem Cole
@ 2020-07-30 16:42   ` Paul Winalski
  2020-08-12  2:09     ` Dave Horsfall
  1 sibling, 1 reply; 6+ messages in thread
From: Paul Winalski @ 2020-07-30 16:42 UTC (permalink / raw)
  To: Dave Horsfall; +Cc: The Eunuchs Hysterical Society

On 7/29/20, Dave Horsfall <dave@horsfall.org> wrote:
>
> Given that the VT05 (shudder!) is broken in so many others ways e.g. 20x72
> screen, sends upper-case only unless you flip an internal switch, etc, I'm
> not surprised that it would also need a CR delay...

The VT05 was designed to be a glass teletype.  Literally.  Hence the
screen width (same as a model 33 tty) and default upper-case only
transmission.  The CR delay might be there to mimic the CR delay of a
model 33, too.

-Paul W.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [TUHS] CR delay for VT05
  2020-07-30 16:42   ` Paul Winalski
@ 2020-08-12  2:09     ` Dave Horsfall
  0 siblings, 0 replies; 6+ messages in thread
From: Dave Horsfall @ 2020-08-12  2:09 UTC (permalink / raw)
  To: The Eunuchs Hysterical Society

On Thu, 30 Jul 2020, Paul Winalski wrote:

> The VT05 was designed to be a glass teletype.  Literally.  Hence the 
> screen width (same as a model 33 tty) and default upper-case only 
> transmission.  The CR delay might be there to mimic the CR delay of a 
> model 33, too.

Aha, thanks!

I seem to recall that the VT05's timing was locked to the mains frequency, 
hence the delays were not easily changed.

Hmmm...  50Hz vs. 60Hz?

-- Dave

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2020-08-12  2:09 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-07-19 23:32 [TUHS] CR delay for VT05 Richard Tobin
2020-07-20  4:28 ` Random832
2020-07-29 23:23 ` Dave Horsfall
2020-07-30  0:56   ` Clem Cole
2020-07-30 16:42   ` Paul Winalski
2020-08-12  2:09     ` Dave Horsfall

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