5 Mar
2015
5 Mar
'15
10:34 a.m.
Can anyone tell me anything about the subject: line? It seems to be a high-end graphics
terminal from the
mid 1970s. I have found the electronics unit while unpacking here, I think I have the
keyboard (with a little
built-in joystick?) somewhere too. I don't have the monitor, but I am guessing
it's TV rates.
Pysically it's just a metal box (about the size of a 4U rack unit without flanges).
There is nothing on the front
panel. The back panel has the on/off switch and connectors for a keyboard (DA15),
'Digital Video' (ditto),
Host and Downstream RS232 ports (DB25, of course) Host and Dowstream current loop ports
(DE9), 3 video
outputs (BNC, I assume these can be used as R,G,B), mix video output (ditto) and video
input (my guess is that
the terminal video can be overlayed on some other video signal, again a BNC).
The top cover comes off with 2 screws. It reveals very little apart from a massive linear
PSU. The interesting
stuff is exposed by removing the front panel (4 screws) which gives access to the card
cage. There are 2
columns of half-width cards at the top, then about 7 full width ones. 2 of the half-width
cards are wire-wrapped
not PCBs. I forget what they do, one of them seems to be the video timing/sync counters.
On other half-width
cards are the processor (6800), ROMs (lots of EPROMs),Comms, video output (resistor DACs,
etc) and
a 'vector generator' which I guess is to draw lines, it's just a lot of of
logic ICs, no microprocessor.
One of the full-width cards is something like 'area fill'. So it does that in
hardware too? The others -- and there
are half a dozen of them -- are 'Pixel Store'. Each has 16K*16 of DRAM and a 16
bit ALU (4 off 74181).
I hate to think how much this cost when new. RAM and ALUs were not cheap!
-tony
5 Mar
5 Mar
1:14 p.m.
Cool find!
One of the full-width cards is something like
'area fill'. So it does that in hardware too?
Yes, probably, it is not that big trick (in theory). Example Amiga's custom chipsets
was capable for area fill (line mode), and btw, prototype of that custom chip set was made
from TTL chips:http://www.floodgap.com/retrobits/ckb/secret/cbm-lorraine-portrait.jpg
Please send some photos of that Sigma's miracle!
- Johannes ThelenFinland
Before microcomputers blog (Finnish) http://ennenmikrotietokoneita.blogspot.fi/
From: ard at p850ug1.demon.co.uk
To: cctalk at classiccmp.org
Subject: Sigma Electronics Systems Display Generator 5564
Date: Thu, 5 Mar 2015 18:34:30 +0000
Can anyone tell me anything about the subject: line? It seems to be a high-end graphics
terminal from the
mid 1970s. I have found the electronics unit while unpacking here, I think I have the
keyboard (with a little
built-in joystick?) somewhere too. I don't have the monitor, but I am guessing
it's TV rates.
Pysically it's just a metal box (about the size of a 4U rack unit without flanges).
There is nothing on the front
panel. The back panel has the on/off switch and connectors for a keyboard (DA15),
'Digital Video' (ditto),
Host and Downstream RS232 ports (DB25, of course) Host and Dowstream current loop ports
(DE9), 3 video
outputs (BNC, I assume these can be used as R,G,B), mix video output (ditto) and video
input (my guess is that
the terminal video can be overlayed on some other video signal, again a BNC).
The top cover comes off with 2 screws. It reveals very little apart from a massive linear
PSU. The interesting
stuff is exposed by removing the front panel (4 screws) which gives access to the card
cage. There are 2
columns of half-width cards at the top, then about 7 full width ones. 2 of the half-width
cards are wire-wrapped
not PCBs. I forget what they do, one of them seems to be the video timing/sync counters.
On other half-width
cards are the processor (6800), ROMs (lots of EPROMs),Comms, video output (resistor DACs,
etc) and
a 'vector generator' which I guess is to draw lines, it's just a lot of of
logic ICs, no microprocessor.
One of the full-width cards is something like 'area fill'. So it does that in
hardware too? The others -- and there
are half a dozen of them -- are 'Pixel Store'. Each has 16K*16 of DRAM and a 16
bit ALU (4 off 74181).
I hate to think how much this cost when new. RAM and ALUs were not cheap!
-tony
10:07 p.m.
Cool find!
I think I rescued it about 25 years ago, as it looked interesting. It then got somewhat
hidden in my old house and
has turned up in the move. Fortuantely [1] my new house is mine alone so I can put classic
computers everywhere
[1] Don't take that the wrong way. I wish my parents were still alive, I think of them
every day. But living in
their house meant I had to (very reasonably) go with their rules.
One of the full-width cards is something like 'area fill'. So it does that in
hardware too?
Yes, probably, it is not that big trick (in theory). Example Amiga's custom chipsets
was capable for area fill (line
mode), and btw, prototype of that custom chip set was made from TTL
chips:http://www.floodgap.com/retrobits
/ckb/secret/cbm-lorraine-portrait.jpg
Sure. My guess is that the line drawing on this terminal is going to be similar to that on
the HP2623. A simple
state machine where the main CPU (in the HP a Z80, in the Sigma a 6800) calculates various
parameters and
the state machine goes along setting pixels. The area fill board is perhaps 50 or so TTL
ICs. Not complex
really. But I think it is a high-end feature for a 1970s terminal.
Please send some photos of that Sigma's miracle!
Will do.
-tony
6 Mar
6 Mar
10:33 a.m.
On Mar 6, 2015, at 1:07 AM, tony duell <ard at
p850ug1.demon.co.uk> wrote:
It?s interesting to compare with the PLATO terminals. The first plasma panel terminal
(?PLATO IV?, ?Magnavox?) is from the early 1970, all hardwired logic. It does line
drawing in hardware, essentially the Bresenham algorithm. It doesn?t have area fill.
The ?PLATO V? terminal is a 1976 successor, using an 8080 with some hardware assist (the
Bresenham per-pixel step is in hardware, but the full line loop is in software). That one
initially did not have area fill but a somewhat later successor added that, in software.
So, high end feature, I suppose; PLATO terminals were used in fair numbers but were not
mainstream graphics terminals.
paul
...
One of the full-width cards is something like 'area fill'. So it does that in
hardware too?
Yes, probably, it is not that big trick (in theory). Example Amiga's custom chipsets
was capable for area fill (line
mode), and btw, prototype of that custom chip set was made from TTL
chips:http://www.floodgap.com/retrobits
/ckb/secret/cbm-lorraine-portrait.jpg
Sure. My guess is that the line drawing on this terminal is going to be similar to that
on the HP2623. A simple
state machine where the main CPU (in the HP a Z80, in the Sigma a 6800) calculates
various parameters and
the state machine goes along setting pixels. The area fill board is perhaps 50 or so TTL
ICs. Not complex
really. But I think it is a high-end feature for a 1970s terminal.
8 Mar
8 Mar
8:53 a.m.
Please send some photos of that Sigma's miracle!
I have posted a few pictures of the unit and the PCB in it on my flickr account. You can
find them here :
https://www.flickr.com/photos/tony_duell/sets/72157651171931246/
-tony
9 Mar
9 Mar
1:56 p.m.
Thanks for photos!
Chip codes seems from 77...79. It is obvious, it is not mass producted (board type, also
serial no. of vector board is 039). Maybe tailor made for some special CAD system?
"Vector Gen" board seems some nice Signetics chips, like weird multiport 8x4-bit
ram (82S112), maybe used as some buffer? Top of that same card goes 12-bit bus to 8263
multiplexers (wild guess: 4-bit for each color?). Also there is 32x8 PROMs (82S23),
maybe used as glue logic / sequencer, too small for look up table.
How many 16Kx16 + ALUs board there were? Three? Maybe there is one processor/memory for
each color plane...
You have to put that back to live, and make some reverse engineering. It seems to be
really exciting machine!
- Johannes ThelenFinland
Before microcomputers blog (Finnish) http://ennenmikrotietokoneita.blogspot.fi/
From: ard at p850ug1.demon.co.uk
To: cctech at classiccmp.org
Subject: RE: Sigma Electronics Systems Display Generator 5564
Date: Sun, 8 Mar 2015 15:53:19 +0000
Please send some photos of that Sigma's
miracle!
I have posted a few pictures of the unit and the PCB in it on my flickr account. You can
find them here :
https://www.flickr.com/photos/tony_duell/sets/72157651171931246/
-tony
2:04 p.m.
Thanks for photos!
Chip codes seems from 77...79. It is obvious, it is not mass producted (board type, also
serial no. of vector
board is 039). Maybe tailor made for some special CAD system?
The fact that 2 of the boards are wire-wrapped not PCBs suggests it was a low-production
unit, but equally it
is too well made to be a one-off kludge IMHO.
"Vector Gen" board seems some nice Signetics chips, like weird multiport
8x4-bit ram (82S112), maybe used as
some buffer? Top of that same card goes 12-bit bus to 8263 multiplexers (wild guess:
4-bit for each color?).
I suspect it's similar to the little state machine in the HP2623 terminal for line
drawing and these RAMs contain the
parameters for the state machine.
I doubt it's 4 bits per colour, I suspect lines are drawn one at a time, you specify
the colour, the state machine
does its thing and the colour setting simply determines which bits in the video RAM are
changed. So the
vector generator would not know anything about the colour
Also there is 32x8 PROMs (82S23), maybe used as glue
logic / sequencer, too small for look up table.
I think that's a state machine type of sequencer.
How many 16Kx16 + ALUs board there were? Three? Maybe there is one processor/memory for
each color
plane...
6 of them. It might be 2 boards per colour, but one thing I didn't notice until later
were the 74189 RAMs on
the video processor board (the one with the DACs on it). My guess is that these are a
colour look up table
forming a mapping between bits in video RAM and the DACs (maybe 3 off 5 bit DACs). This
suggests 4 bits
per pixel (to address the CLUT RAMs) at the video memory side, how that fits in with the 6
Pixel Store boards
I don't know.
You have to put that back to live, and make some reverse engineering. It seems to be
really exciting machine!
It is going to be a big job to sort it out, but one that will be worth doing. That is,
unless manuals for it turn up...
-tony
3:32 p.m.
Sounds really weird, six times memory and ALUs..? Maybe that another set of three CPU+MEMs
are just for another independend graphic layer?
I noticed before, but there is VIDEO IN connector. What if this is video mixer, I mean
system which you can made text and etc. effects to over real time video... Where that
video in goes, to same video processor board..?
Anyways, this can be long shot, but eBay is full of Sigma Electronics Inc. (not Ltd.)
video generators and mixers, like this...
http://www.ebay.com/itm/Sigma-Electronics-SS-2100-16-Plus-HSB-16-Video-Swit…
Same company..? http://www.sigmatechsys.com/index.htm ...send photo to them, maybe they
regocnize that box!
- Johannes ThelenFinland
Before microcomputers blog (Finnish) http://ennenmikrotietokoneita.blogspot.fi/
From: ard at p850ug1.demon.co.uk
To: cctech at classiccmp.org
Subject: RE: Sigma Electronics Systems Display Generator 5564
Date: Mon, 9 Mar 2015 21:04:28 +0000
Thanks for photos!
Chip codes seems from 77...79. It is obvious, it is not mass producted (board type, also
serial no. of vector
board is 039). Maybe tailor made for some special CAD system?
The fact that 2 of the boards are wire-wrapped not PCBs suggests it was a low-production
unit, but equally it
is too well made to be a one-off kludge IMHO.
"Vector Gen" board seems some nice Signetics chips, like weird multiport
8x4-bit ram (82S112), maybe used as
some buffer? Top of that same card goes 12-bit bus to 8263 multiplexers (wild guess:
4-bit for each color?).
I suspect it's similar to the little state machine in the HP2623 terminal for line
drawing and these RAMs contain the
parameters for the state machine.
I doubt it's 4 bits per colour, I suspect lines are drawn one at a time, you specify
the colour, the state machine
does its thing and the colour setting simply determines which bits in the video RAM are
changed. So the
vector generator would not know anything about the colour
Also there is 32x8 PROMs (82S23), maybe used as
glue logic / sequencer, too small for look up table.
I think that's a state machine type of sequencer.
How many 16Kx16 + ALUs board there were? Three? Maybe there is one processor/memory for
each color
plane...
6 of them. It might be 2 boards per colour, but one thing I didn't notice until later
were the 74189 RAMs on
the video processor board (the one with the DACs on it). My guess is that these are a
colour look up table
forming a mapping between bits in video RAM and the DACs (maybe 3 off 5 bit DACs). This
suggests 4 bits
per pixel (to address the CLUT RAMs) at the video memory side, how that fits in with the
6 Pixel Store boards
I don't know.
You have to put that back to live, and make some reverse engineering. It seems to be
really exciting machine!
It is going to be a big job to sort it out, but one that will be worth doing. That is,
unless manuals for it turn up...
-tony
9:59 p.m.
Sounds really weird, six times memory and ALUs..?
Maybe that another set of three CPU+MEMs are just for
another independend graphic layer?
Maybe, but I suspect it's more interesting than that.
I noticed before, but there is VIDEO IN connector.
What if this is video mixer, I mean system which you can
made text and etc. effects to over real time video... Where that video in goes, to same
video processor board..?
Yes, the 5 BNCs are wired to that 20 way ribbon cable (seen in the picture of the front
view of the cardcage). That
plugs into the header on the video processor board. There are 2 wires each for the centre
and shield of each BNC,
maybe to get the characteristic impedence of the cable correct.
My guess is that it is like the video input on the VT100. The video outputs from the unit
are added (analogue)
to this signal and fed to the output BNCs. The external video source has to be synced to
the terminal rather than
vice versa.
-tony
6 Mar
6 Mar
9:44 a.m.
tor 2015-03-05 klockan 18:34 +0000 skrev tony duell:
Can anyone tell me anything about the subject: line?
It seems to be a high-end graphics terminal from the
mid 1970s. I have found the electronics unit while unpacking here, I think I have the
keyboard (with a little
built-in joystick?) somewhere too. I don't have the monitor, but I am guessing
it's TV rates.
I think that the school were i was 1988-1989 had one of those.
The school had an PR1ME 9955.
The student computer association had the terminal. We mainly used it to
view mandelbrot sets.
It took 4 hours to render a complete screen.
3575
days inactive
3580
days old
9 comments
4 participants
participants (4)
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ard＠p850ug1.demon.co.uk -
johannesthelen＠hotmail.com -
paulkoning＠comcast.net -
stefan.skoglund＠agj.net