8 Dec
2011
8 Dec
'11
9:46 p.m.
On 8 Dec 2011 at 19:47, Bill Sudbrink wrote:
I'm thinking of building a "somewhat
vintage" two-channel DAC board,
intended to drive an oscilloscope as a vector display.
Well, if you want "vintage" (and I assume you do) there was at least
one such project in an old issue of Byte or Kilobaud (IIRC).
Given that typical period (I'm assuming vintage all the way) o-
scope's linearity is none too wonderful, you might get away with a
single 8255 PPI (or similar parallel chip) and a simple R-2R "ladder"
DAC. You can't get much cheaper than that.
--Chuck
8 Dec
8 Dec
10:13 p.m.
The HP1350 and 1351 are vector generators that have no CPU, just
a state machine. Service manuals are aon bitsavers, i.e.
<http://bitsavers.org/pdf/hp/graphics/01351-90904_1351A_svc_Jul81.pdf>
--
"The Direct3D Graphics Pipeline" -- DirectX 9 version available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
10:18 p.m.
Bill Sudbrink wrote:
I'm thinking of building a "somewhat
vintage" two-channel DAC board,
intended to drive an oscilloscope as a vector display.
Chuck Guzis wrote:
Well, if you want "vintage" (and I assume
you do) there was at least
one such project in an old issue of Byte or Kilobaud (IIRC).
"Build the Beer Budget Graphics Interface" by Peter Nelson, in the November 1976
Byte, is a simple point-plot display.
"Make Your Next Peripheral a Real Eye Opener" by Steve Ciarcia, in the November
1976 Byte, with errata in the March 1977 Byte, is a vector display.
"Microvec: The Other Type of Video Display" by Billy Garrett, in the November
1982 Byte, takes the Ciarcia "Eye Opener" design (completely uncredited!) and
adds a Z-80 processor system to turn it into a peripheral with a parallel interface.
Apparently Garrett won third prize in an IEEE Region 3 Student Paper Contest; I wonder if
the paper submitted to IEEE credited Ciarcia?
Eric
10:36 p.m.
Date: Thu, 8 Dec 2011 19:18:44 -0800
From: eric at brouhaha.com
To:
Subject: Re: Oscilloscope vector display driver...
Bill Sudbrink wrote:
You should start with this:
http://www.jmargolin.com/vgens/vgens.htm
I'm thinking of building a "somewhat
vintage" two-channel DAC board,
intended to drive an oscilloscope as a vector display.
Chuck Guzis wrote:
Well, if you want "vintage" (and I
assume you do) there was at least
one such project in an old issue of Byte or Kilobaud (IIRC).
"Build the Beer Budget Graphics Interface" by Peter Nelson, in the November
1976 Byte, is a simple point-plot display.
"Make Your Next Peripheral a Real Eye Opener" by Steve Ciarcia, in the November
1976 Byte, with errata in the March 1977 Byte, is a vector display.
"Microvec: The Other Type of Video Display" by Billy Garrett, in the November
1982 Byte, takes the Ciarcia "Eye Opener" design (completely uncredited!) and
adds a Z-80 processor system to turn it into a peripheral with a parallel interface.
Apparently Garrett won third prize in an IEEE Region 3 Student Paper Contest; I wonder if
the paper submitted to IEEE credited Ciarcia?
Eric
9 Dec
9 Dec
5:21 p.m.
The circuit from the Vectrex videogame console might be an interesting
option. It was based on the 6809 and so should be trivial to adapt for a
6800 machine. It uses analog circuits to draw lines: you set up the
initial x and y values, select the final x and y and let the circuit
interpolate between the two while the processor has time to do other
things.
The schematics are on pages 33 to 48 (and is explained in earlier pages)
of:
http://www.vectrex.nl/docs/vecman.pdf
The needed components are very cheap.
-- Jecel
4:44 p.m.
In article <201112092124.pB9LNw61073022 at billy.ezwind.net>,
"Jecel Assumpcao Jr." <jecel at merlintec.com> writes:
The circuit from the Vectrex videogame console might
be an interesting
option. It was based on the 6809 and so should be trivial to adapt for a
6800 machine. It uses analog circuits to draw lines: you set up the
initial x and y values, select the final x and y and let the circuit
interpolate between the two while the processor has time to do other
things.
The Tektronix 401x terminals also have a similar set of analog
circuitry driven by TTL combinatorial logic that handles decoding the
escape codes. Schematics are on bitsavers.
--
"The Direct3D Graphics Pipeline" -- DirectX 9 version available for download
<http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/>
Legalize Adulthood! <http://legalizeadulthood.wordpress.com>
11 Dec
11 Dec
7:38 a.m.
Am 09.12.2011 04:18, schrieb Eric Smith:
Bill Sudbrink wrote:
"Make Your Next Peripheral a Real Eye Opener" by Steve Ciarcia, in the
November 1976 Byte, with errata in the March 1977 Byte, is a vector
display.
I was able to find the Nov 1976 Byte online but not the Mar 1977 issue.
Does anyone have the errata scanned?
Thanks
Sebastian
12:51 p.m.
Sebastian Brueckner wrote:
Am 09.12.2011 04:18, schrieb Eric Smith:
> Bill Sudbrink wrote:
> "Make Your Next Peripheral a Real Eye Opener" by Steve Ciarcia, in the
> November 1976 Byte, with errata in the March 1977 Byte, is a vector
> display.
Bill didn't write that, I did.
I was able to find the Nov 1976 Byte online but not
the
Mar 1977 issue. Does anyone have the errata scanned?
<p><b>Why the DACs "Don't Work"</b></p>
<p>
Author Steve Ciarcia sent our way
(via his friend Chris Morgan who stopped
by one recent Saturday) the following
correction to his article "Make Your
Next Peripheral a Real Eye Opener" on
page 78 of the November 1976 BYTE. In
the schematic of pages 84 and 85 (fig-
ure 2), we (Steve or CH at BYTE? Who
knows?) omitted notation of the nega-
tive supply pin for the MC1408-L8
digital to analog converters, IC4 and IC5.
Pin 3 of each 1408 should be wired to
the -15 V supply.
</p>
9 Dec
9 Dec
7:02 p.m.
On 09/12/11 02:46, Chuck Guzis wrote:
Well, if you want "vintage" (and I assume
you do) there was at least
one such project in an old issue of Byte or Kilobaud (IIRC).
There was one in Popular Electronics way-back-when. The "Scopewriter".
--
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/
4608
days inactive
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