19 Aug
2015
19 Aug
'15
10:09 p.m.
Would anyone have a surplus-to-needs, or know of a source for, a VT100 keyboard?
This would actually be for the DECmateI/VT278 I mentioned on the list a couple weeks ago,
Rob and I are looking into doing something with it.
Alternatively, does anyone know if there is any degree of signalling compatibility between
the VT100 and VT220/320 keyboards?
Those RX floppies in the pedestal on ebay mentioned a week or two ago were just what was
needed to complete it, as they actually looked like they were part of a 278, but the
listing was removed from ebay.
19 Aug
19 Aug
10:17 p.m.
On Wed, Aug 19, 2015 at 5:09 PM, Brent Hilpert <hilpert at cs.ubc.ca> wrote:
Would anyone have a surplus-to-needs, or know of a
source for, a VT100 keyboard?
I have terminals and keyboards, but I don't know that I have more
working keyboards than working terminals.
This would actually be for the DECmateI/VT278 I
mentioned on the list a couple weeks ago, Rob and I are looking into doing something with
it.
Cool. I have one of those myself - just the basics - no addon cards,
one set of floppies (room in the pedestal to add more), but I do have
the "desk" upgrade (a metal clip that mounts where the keyboard tray
normally goes, and a desk top and left-side leg so you have a
workspace right in front of you rather than hunching up in front of
the pedestal).
Alternatively, does anyone know if there is any degree
of signalling compatibility between the VT100 and VT220/320 keyboards?
None. The VT100 keyboard is 3-wire: power, ground, and bidirectional
data with a dumb hardware UART in the keyboard; the VT220/320
keyboards (LK201 et al.) have a 4-wire interface with power, ground,
tx, and rx, and a sophisticated (by comparison) character protocol.
Those RX floppies in the pedestal on ebay mentioned a
week
or two ago were just what was needed to complete it,
as they actually looked like they were part of a 278
Yes. Except for missing the "wood" top, that did look to me like a
VT278 floppy pedestal. You don't "need" that if you have room for a
side-by-side RX01 or RX02. That pedestal is just mounting and
packaging (along with a passive DB25<->Berg 40 adapter). You could
use the same floppy cabinet as a MINC-11 with (AFAIK) the same cables.
I think there is only one DEC standard for running an RX drive over
DB25. The only part that might matter is RX01 vs RX02 (I _think_
MINCs came with either by the end). Either way, the floppy drive guts
are all the same across all the lines. You can just get them in 3
packages (rack-mount, tabletop, or pedestal). It's only about
mounting (and 40-pin internal vs 25-pin external).
-ethan
10:48 p.m.
On 2015-Aug-19, at 2:17 PM, Ethan Dicks wrote:
On Wed, Aug 19, 2015 at 5:09 PM, Brent Hilpert
<hilpert at cs.ubc.ca> wrote:
Thanks, that was a question I had been intending to ask, but to confirm:
If one obtained (as appropriate) bare RX01/2 floppy drive(s), it would just be a matter of
power supply for the floppies, and passive cabling to interface the drives to the
CPU/display?
I actually have the DB25-to-DC37 cable that goes between the disk unit and the DC37
connector on the CPU/display unit.
If we move this along we may be asking for system software in the future, I haven't
looked at what may be readily available (i.e. bitsavers) as yet.
Would anyone have a surplus-to-needs, or know of
a source for, a VT100 keyboard?
I have terminals and keyboards, but I don't know that I have more
working keyboards than working terminals.
This would actually be for the DECmateI/VT278 I
mentioned on the list a couple weeks ago, Rob and I are looking into doing something with
it.
Cool. I have one of those myself - just the basics - no addon cards,
one set of floppies (room in the pedestal to add more), but I do have
the "desk" upgrade (a metal clip that mounts where the keyboard tray
normally goes, and a desk top and left-side leg so you have a
workspace right in front of you rather than hunching up in front of
the pedestal).
Alternatively, does anyone know if there is any
degree of signalling compatibility between the VT100 and VT220/320 keyboards?
None. The VT100 keyboard is 3-wire: power, ground, and bidirectional
data with a dumb hardware UART in the keyboard; the VT220/320
keyboards (LK201 et al.) have a 4-wire interface with power, ground,
tx, and rx, and a sophisticated (by comparison) character protocol.
Those RX floppies in the pedestal on ebay
mentioned a week
or two ago were just what was needed to complete it,
as they actually looked like they were part of a 278
Yes. Except for missing the "wood" top, that did look to me like a
VT278 floppy pedestal. You don't "need" that if you have room for a
side-by-side RX01 or RX02. That pedestal is just mounting and
packaging (along with a passive DB25<->Berg 40 adapter). You could
use the same floppy cabinet as a MINC-11 with (AFAIK) the same cables.
I think there is only one DEC standard for running an RX drive over
DB25. The only part that might matter is RX01 vs RX02 (I _think_
MINCs came with either by the end). Either way, the floppy drive guts
are all the same across all the lines. You can just get them in 3
packages (rack-mount, tabletop, or pedestal). It's only about
mounting (and 40-pin internal vs 25-pin external). 
20 Aug
20 Aug
12:05 a.m.
The cable for the RX01/02 to the various interfaces is the BC05L-15. Either
cable will work on them.
Paul
On Wed, Aug 19, 2015 at 4:48 PM, Brent Hilpert <hilpert at cs.ubc.ca> wrote:
On 2015-Aug-19, at 2:17 PM, Ethan Dicks wrote:
On Wed, Aug 19, 2015 at 5:09 PM, Brent Hilpert
<hilpert at cs.ubc.ca>
wrote:
> Would anyone have a surplus-to-needs, or know
of a source for, a VT100
keyboard?
I have terminals and keyboards, but I don't know that I have more
working keyboards than working terminals.
> This would actually be for the DECmateI/VT278 I mentioned on the list a
couple
weeks ago, Rob and I are looking into doing something with it.
Cool. I have one of those myself - just the basics - no addon cards,
one set of floppies (room in the pedestal to add more), but I do have
the "desk" upgrade (a metal clip that mounts where the keyboard tray
normally goes, and a desk top and left-side leg so you have a
workspace right in front of you rather than hunching up in front of
the pedestal).
> Alternatively, does anyone know if there is any degree of signalling
compatibility between the VT100 and VT220/320 keyboards?
None. The VT100 keyboard is 3-wire: power, ground, and bidirectional
data with a dumb hardware UART in the keyboard; the VT220/320
keyboards (LK201 et al.) have a 4-wire interface with power, ground,
tx, and rx, and a sophisticated (by comparison) character protocol.
Thanks, that was a question I had been intending to ask, but to confirm:
If one obtained (as appropriate) bare RX01/2 floppy drive(s), it would
just be a matter of power supply for the floppies, and passive cabling to
interface the drives to the CPU/display?
I actually have the DB25-to-DC37 cable that goes between the disk unit and
the DC37 connector on the CPU/display unit.
If we move this along we may be asking for system software in the future,
I haven't looked at what may be readily available (i.e. bitsavers) as yet.
Those RX floppies in the pedestal on ebay
mentioned a week
or two ago were just what was needed to complete it,
as they actually looked like they were part of a 278
Yes. Except for missing the "wood" top, that did look to me like a
VT278 floppy pedestal. You don't "need" that if you have room for a
side-by-side RX01 or RX02. That pedestal is just mounting and
packaging (along with a passive DB25<->Berg 40 adapter). You could
use the same floppy cabinet as a MINC-11 with (AFAIK) the same cables.
I think there is only one DEC standard for running an RX drive over
DB25. The only part that might matter is RX01 vs RX02 (I _think_
MINCs came with either by the end). Either way, the floppy drive guts
are all the same across all the lines. You can just get them in 3
packages (rack-mount, tabletop, or pedestal). It's only about
mounting (and 40-pin internal vs 25-pin external). 
5:47 a.m.
Thanks, that was a question I had been intending to ask, but to confirm:
If one obtained (as appropriate) bare RX01/2 floppy drive(s), it would just be a
matter of power supply for the floppies, and passive cabling to interface the drives
to the CPU/display?
Depends on what you mean by 'bare floppy drives'.
An RX01/RX02 (all versions, rackmount, tabletop, etc) contains a pair of totally bare
drives (no electronics at all), a PSU, and 2 PCBs. One is essentially the stuff you would
expect to find on floppy drives (read/write, stepper drivers etc), the other is a
microcoded
controller (TTL in the RX01, AM2900 in the RX02). The host interface is a custom serial
one,
The rackmount units use a 40 wire Berg cable to link to the bus interface in the
PDP8/PDP11.
In the tabletop unit (and I assume the pedestal, but I have never seen one) there is a
little PCB
with a Berg plug and a DB25 connector that links to the controller board. It is just the
connectors,
no electronics. It route the signals to pins on the DB25.
So if you got a complete rackmount RX01/RX02 you could make up a special cable to link it
to the DECMate. I did the reverse to link a tabletop unit to a RX8E.
-tony
5:41 a.m.
Alternatively, does anyone know if there is any degree of signalling compatibility
between the VT100 and VT220/320 keyboards?
I am sure there is no compatibility. The VT220, etc keyboard (LK201) interface is a 9600
baud
asynchronous serial port. The VT100 keyboard has a single bidirectional data line, which
something
tells me carries clock and data.
It would of course be possible to make an interface between them, or to make a VT100
compatible
keyboard from scratch (schematics are in the VT100 printset and the keyboard is all
standard ICs,
including one of those dumb 40 pin UARTs). But it's not just a cable adapter.
-tony
3437
days inactive
3438
days old
5 comments
4 participants
participants (4)
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ard＠p850ug1.demon.co.uk -
ethan.dicks＠gmail.com -
hilpert＠cs.ubc.ca -
useddec＠gmail.com