* [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
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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
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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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