3 May
2004
3 May
'04
11:51 p.m.
Does anyone know, or know of a reference to, the serial-line protocol
spoken by Summagraphics tablet digitizers (specifically, the MM1103)?
I have one. After a bit of detective work, I got it to at least
somewhat work. I now have it to the point where I can connect it up
and turn it on. When I do, I get nothing until one of the buttons on
the puck is pressed, at which point it starts generating a stream of
samples, continuing for as long as some button is pressed. The format
is fairly easy, just %04d,%04d,%1d\n sent with the 0x80 bits set to
provide even parity, where the four-digit numbers are the location
(based on an 8.5" edge of a piece of paper and some arithmetic, it
appears to be 200dpi) and the last indicates what button is pressed.
This makes it all at least somewhat usable. But I'd really like to be
able to get samples back even when no buttons are pressed, whence my
question.
The back does include a sticker saying, among other things, "BIT PAD
FORMAT", which may or may not mean anything useful. I did go
a-googling, but either there's nothing to be found or I didn't guess
the right incantation to find it. `Summagraphics MM1103 serial
protocol' turns up no hits - though it probably will once this message
gets archived and googled :) - and neither did `"bit pad format"'.
It _is_ on-topic; there's a sticker on the back with a Date: field
containing a handwritten date that is clearly in 1984 (it appears to
read "10/17/84"), which contains other text implying it was added by a
leasing/service organization.
Thoughts?
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4 May
4 May
12:52 a.m.
I have a SummaSketch MM1201 and the documentation for it.
The protocol doesn't match your description.
But maybe it helps a little bit anyway.
Baud Rate: 9600
# Start Bits: 1
# Stop Bits: 1
# Data Bits: 8
Parity Bit: Odd
Data Format:
MSB bits LSB
7 6 5 4 3 2 1 0
byte 1 1 PR 0 Sx Sy Fc Fb Fa
byte 2 0 X6 X5 X4 X3 X2 X1 X0
byte 3 0 X13 X12 X11 X10 X9 X8 X7
byte 4 0 Y6 Y5 Y4 Y3 Y2 Y1 Y0
byte 5 0 Y13 Y12 Y11 Y10 Y9 Y8 Y7
F is the flag bit, identifying the stylus or
puck buttons being pressed:
Stylus Puck Binary Output
Buttons Buttons Fc Fb Fa
none none 0 0 0
tip button 1 0 0 1
barrel button 2 0 1 0
tip and barrel 3 0 1 1
- 4 1 0 0
- 1+2 0 1 1
- 1+3 0 1 1
- 1+4 1 0 1
- 2+3 0 1 1
- 2+4 1 1 0
- 1+2+3 0 1 1
- 1+2+4 1 1 1
- 2+3+4 1 1 1
- 1+2+3+4 1 1 1
Sy and Sx are the sign bits for the Y and X coordinates.
1 is positive.
0 is negative.
PR is the proximity bit.
When stylus or puck is in proximity, the bit is 0.
When out of proximity, it is 1.
X0..X13 and Y0..Y13 are the X and Y coordinates.
Gerold
der Mouse schrieb:
Does anyone know, or know of a reference to, the
serial-line protocol
spoken by Summagraphics tablet digitizers (specifically, the MM1103)?
I have one. After a bit of detective work, I got it to at least
somewhat work. I now have it to the point where I can connect it up
and turn it on. When I do, I get nothing until one of the buttons on
the puck is pressed, at which point it starts generating a stream of
samples, continuing for as long as some button is pressed. The format
is fairly easy, just %04d,%04d,%1d\n sent with the 0x80 bits set to
provide even parity, where the four-digit numbers are the location
(based on an 8.5" edge of a piece of paper and some arithmetic, it
appears to be 200dpi) and the last indicates what button is pressed.
This makes it all at least somewhat usable. But I'd really like to be
able to get samples back even when no buttons are pressed, whence my
question.
The back does include a sticker saying, among other things, "BIT PAD
FORMAT", which may or may not mean anything useful. I did go
a-googling, but either there's nothing to be found or I didn't guess
the right incantation to find it. `Summagraphics MM1103 serial
protocol' turns up no hits - though it probably will once this message
gets archived and googled :) - and neither did `"bit pad format"'.
It _is_ on-topic; there's a sticker on the back with a Date: field
containing a handwritten date that is clearly in 1984 (it appears to
read "10/17/84"), which contains other text implying it was added by a
leasing/service organization.
Thoughts?
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2:05 p.m.
I have a SummaSketch MM1201 and the documentation for it.
The protocol doesn't match your description.
[...]
Data Format:
MSB bits LSB
7 6 5 4 3 2 1 0
byte 1 1 PR 0 Sx Sy Fc Fb Fa
byte 2 0 X6 X5 X4 X3 X2 X1 X0
byte 3 0 X13 X12 X11 X10 X9 X8 X7
byte 4 0 Y6 Y5 Y4 Y3 Y2 Y1 Y0
byte 5 0 Y13 Y12 Y11 Y10 Y9 Y8 Y7
That seems to be the 'bianry' protocol that I remember from the Bit Pad
1. I couldnt have reproduced it from memory, but seeing that reminded me
of things like the 1st byte had the MSB set, all others had it cleared,
and so on.
-tony
2:02 p.m.
Does anyone know, or know of a reference to, the serial-line protocol
spoken by Summagraphics tablet digitizers (specifically, the MM1103)?
[..]
This makes it all at least somewhat usable. But
I'd really like to be
able to get samples back even when no buttons are pressed, whence my
question.
The back does include a sticker saying, among other things, "BIT PAD
FORMAT", which may or may not mean anything useful. I did go
The Sumagraphics Bit Pad 1 was a very common tablet at one time. From
waht I remember, and I do have the manual _somewhere_ (this being a real
manual which documents the data format and includes schematics), there
were 2 output formats. One was ASCII, sending the position in decimal
(that;s what you've got), the other was binary. Which you got was set by
a DIP switch inside.
Another switch turned on streaming mode (I think that's what they called
it) which caused the thing to send out coordinates all the time, even
without a puck button being pressed. I think that's the mode you're
asking for,
I would guess you need to find the right DIP switches inside, which are
doubtless different to those on the Bit Pad 1
-tony
2:16 p.m.
der Mouse wrote:
Does anyone know, or know of a reference to, the
serial-line protocol
spoken by Summagraphics tablet digitizers (specifically, the MM1103)?
I have two Summagraphics manuals, for the "Bit Pad One" and the "MM2101
and MM961 Data Tablets". They both list protocols, bit rates,
DIP-switch setting and so on.
Perhaps the Bit Pad One manual would be the one to look at?
--
John Honniball
coredump(a)gifford.co.uk
10:34 p.m.
[I wrote]
> Does anyone know, or know of a reference to, the
serial-line
> protocol spoken by Summagraphics tablet digitizers (specifically,
> the MM1103)?
[John Honniball <coredump(a)gifford.co.uk> replied]
I have two Summagraphics manuals, for the "Bit
Pad One" and the
"MM2101 and MM961 Data Tablets". They both list protocols, bit
rates, DIP-switch setting and so on.
Perhaps the Bit Pad One manual would be the one to
look at?
Maybe. But see below.
[ard(a)p850ug1.demon.co.uk (Tony Duell), responding to the same message
of mine]
The Sumagraphics Bit Pad 1 was a very common tablet at
one time.
From waht I remember, and I do have the manual _somewhere_ (this
being a real manual which documents the data format and includes
schematics), there were 2 output formats. [...] Which you got was
set by a DIP switch inside.
Another switch turned on streaming mode [...]. I
think that's the
mode you're asking for,
Right.
I would guess you need to find the right DIP switches
inside, which
are doubtless different to those on the Bit Pad 1
Quite likely.
I have the thing opened up right now. There are 24 DIP switches, three
banks of eight, labeled SW1 through SW3. The settings currently are
thus, with bits numbered according to the markings on the switch banks
and 1=on, 0=off:
12345678 <--bit numbers
SW1 11110110
SW2 11000010
SW3 10110110
There is a good deal of "small" logic, CMOS and TTL in the cases I've
bothered to look at the numbers on, a bunch of discrete components, and
three socketed "big chips": a 2732 UVEPROM with a sticker on which is
handwritten "1103" and "7.9"; a 74C154 (why this is socketed I have
no
idea); and something that looks like a CPU, on which is printed various
things in various ways; I think it's probably an 8031.
There's also a momentary pushbutton switch of no obvious function
(inaccessible with the cover on) labeled SW4 and a six-contact
card-edge connector of equally obscure function.
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5 May
5 May
5:08 a.m.
On Wed, 2004-05-05 at 07:34, der Mouse wrote:
I have the thing opened up right now. There are 24
DIP switches, three
banks of eight, labeled SW1 through SW3.
Yikes! That's a lot of combinations to run through! :-)
I was in the same situation with the old Numonics tablet that I was
given - no documentation anywhere and the standard mode it was
configured for didn't make much sense and wouldn't work with any
drivers. Luckily I only have 8 switches to run through though... I found
something that happened to work with one of the later Numonics drivers.
There is a good deal of "small" logic, CMOS
and TTL in the cases I've
bothered to look at the numbers on, a bunch of discrete components, and
three socketed "big chips": a 2732 UVEPROM with a sticker on which is
handwritten "1103" and "7.9"; a 74C154 (why this is socketed I have
no
idea); and something that looks like a CPU, on which is printed various
things in various ways; I think it's probably an 8031.
Well I suppose they run as a SBC, taking input from the pad and
converting to the necessary protocol before spitting it down the serial
line.
There's also a momentary pushbutton switch of no
obvious function
(inaccessible with the cover on) labeled SW4
reset, to allow an engineer to reset the pad without killing the power
all the time? My Numonics tablet has a reset on the back - I'm not sure
why the user would ever need to do a reset though.
and a six-contact card-edge connector of equally
obscure function.
My tablet's got both a pen and a puck; maybe that's a pen connector?
cheers
Jules
5:15 a.m.
I haven't really been following this thread from the start, and I
don't know what model tablet you have, but Googling for "Summagraphics
tablet switch settings" had a bunch of hits, of which this one looks
promising: http://www.surpac.com/refman/default/config/f.htm
Is that of any help? It lists the names and functions of 3 banks of
8 switches.
--jc
Jules Richardson wrote:
On Wed, 2004-05-05 at 07:34, der Mouse wrote:
I have the thing opened up right now. There are
24 DIP switches, three
banks of eight, labeled SW1 through SW3.
Yikes! That's a lot of combinations to run through! :-)
I was in the same situation with the old Numonics tablet that I was
given - no documentation anywhere and the standard mode it was
configured for didn't make much sense and wouldn't work with any
drivers. Luckily I only have 8 switches to run through though... I found
something that happened to work with one of the later Numonics drivers.
There is a good deal of "small" logic,
CMOS and TTL in the cases I've
bothered to look at the numbers on, a bunch of discrete components, and
three socketed "big chips": a 2732 UVEPROM with a sticker on which is
handwritten "1103" and "7.9"; a 74C154 (why this is socketed I have
no
idea); and something that looks like a CPU, on which is printed various
things in various ways; I think it's probably an 8031.
Well I suppose they run as a SBC, taking input from the pad and
converting to the necessary protocol before spitting it down the serial
line.
There's also a momentary pushbutton switch of
no obvious function
(inaccessible with the cover on) labeled SW4
reset, to allow an engineer to reset the pad without killing the power
all the time? My Numonics tablet has a reset on the back - I'm not sure
why the user would ever need to do a reset though.
and a six-contact card-edge connector of equally
obscure function.
My tablet's got both a pen and a puck; maybe that's a pen connector?
cheers
Jules
9 a.m.
["J.C. Wren" <jcwren(a)jcwren.com>]
[...] I don't know what model tablet you have,
I have an MM1103.
but Googling for "Summagraphics tablet switch
settings" had a bunch
of hits, of which this one looks promising:
Is that of any help? It lists the names and functions
of 3 banks of
8 switches.
...for five different tablets, none of which are Summagraphics. The
only place lynx finds the Summagraphics name in that page is the
emulation setting for ACECAD tablets.
Good thought, though, and thanks for checking.
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10:08 a.m.
Look at
http://www.gtcocalcomp.com/Summafiles/Bit%20Pad%202%20Tech%20Ref.pdf
on their website www.gtcocalcomp.com I also found
new drivers for my MM1201
This should be the right docu
(DIP switches are on the last two pages 60,61) ;-)
Gerold
der Mouse schrieb:
["J.C. Wren" <jcwren(a)jcwren.com>]
--
Gerold Pauler Tel.: +49 30 75 70 42 78
Katharinenstr. 7 Mobil: +49 173 23 49 440
10711 Berlin eMail: gerold.pauler(a)gmx.net
[...] I don't know what model tablet you have,
I have an MM1103.
but Googling for "Summagraphics tablet switch
settings" had a bunch
of hits, of which this one looks promising:
Is that of any help? It lists the names and
functions of 3 banks of
8 switches.
...for five different tablets, none of which are Summagraphics. The
only place lynx finds the Summagraphics name in that page is the
emulation setting for ACECAD tablets.
Good thought, though, and thanks for checking.
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6 May
6 May
10:33 p.m.
[Gerold Pauler <gerold.pauler(a)gmx.net>]
Look at
Lovely. Thank you very much. That is *almost* exactly what I wanted,
certainly close enough to be very useful.
This should be the right docu
(DIP switches are on the last two pages 60,61) ;-)
But those are pages D-2 and D-4, documenting switch banks 1 and 3; page
D-3, which presumably describes DIP switch bank 2, is missing (as is
page D-1, which the table of contents says has a command summary). I
find no documentation on at least one command I stumbled across by
accident, one which causes ASCII reports to end with CR rather than
CRLF; presumably there also exists a command which switches it back to
CRLF. There may exist others too; I'm going to try all 128 ASCII
characters....
However, those are minor. This document is extremely helpful, largely
because the incompletenesses are slight and what it does document
matches, as far as I can tell, the tablet I have. (When I saw the
report-version response documentation, I was fairly sure it would.)
Did you scan it? Do you have any channel to the people who did? I'd
be interested in getting whoever has the paper manual to check it
against the PDF and see what else may be missing....
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11:25 p.m.
der Mouse schrieb:
>http://www.gtcocalcomp.com/Summafiles/Bit%20Pad%202%20Tech%20Ref.pdf
But those are pages D-2 and D-4, documenting switch
banks 1 and 3; page
D-3, which presumably describes DIP switch bank 2, is missing (as is
page D-1, which the table of contents says has a command summary). I
find no documentation on at least one command I stumbled across by
accident, one which causes ASCII reports to end with CR rather than
CRLF; presumably there also exists a command which switches it back to
CRLF. There may exist others too; I'm going to try all 128 ASCII
characters....
Sorry, didn't check it for completeness. :-(
But you find some descriptions for switch #2 on pages 33 and 36 (4-10,
4-12).
Did you scan it? Do you have any channel to the
people who did? I'd
be interested in getting whoever has the paper manual to check it
against the PDF and see what else may be missing....
No, I didn't scan it and sorry I don't have any channel to them.
It was just slow working memory.
After I got my MM1201 I was searching for new drivers and I found them
on their Website.
Now after I remembered them, I thought maybe they also have
some documentation, looked and found it.
They also have stuff for other tablets like calcomp, ..
Gerold
11:27 p.m.
But those are
pages D-2 and D-4, documenting switch banks 1 and 3;
page D-3, which presumably describes DIP switch bank 2, is missing
(as is page D-1, which the table of contents says has a command
summary).
Sorry, didn't check it for completeness. :-( But you find some descriptions for switch #2 on pages
33 and 36
(4-10, 4-12).
Yes, some. It still leaves SW2 switches 1 and 2 undocumented. I have
twice accidentally caused it to switch from CRLF to bare CR for ASCII
reports, but despite trying all 128 ASCII characters have been unable
to do so deliberately. I also have been unable to switch to binary
reports.
I noodled around their website a bit and found an email address, to
which I have sent a note asking about these. We'll see what, if
anything, comes back.
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5 May
5 May
9:10 a.m.
I have the
thing opened up right now. There are 24 DIP switches,
three banks of eight, labeled SW1 through SW3.
Yikes! That's a lot of
combinations to run through! :-) There's
also a momentary pushbutton switch of no obvious function
(inaccessible with the cover on) labeled SW4
reset, to allow an engineer to reset
the pad without killing the
power all the time? and a
six-contact card-edge connector of equally obscure function.
My tablet's got
both a pen and a puck; maybe that's a pen connector?
2:49 p.m.
The pc board is only two-layer, though, just front and
back. I may try
to trace where the switches connect to to see which ones are plausible
guesses for what I want.
If it's anything like the BP1, those switches are read in firmware by the
microcontroller. Unless you fancy disassembling the firmware, you'll not
make any sense of them.
-tony
8:29 p.m.
I may try to
trace where the switches connect to to see which ones
are plausible guesses for what I want.
If it's anything like the BP1, those
switches are read in firmware by
the microcontroller. Unless you fancy disassembling the firmware,
you'll not make any sense of them.
2:46 p.m.
Well I suppose they run as a SBC, taking input from
the pad and
converting to the necessary protocol before spitting it down the serial
line.
The 'pad' has no intellegence of its own, and does nothing without the
microcontroller.
Basically, the microcontroller triggers a thyristor (SCR) on the tablet
driver PCB (actually iside the tablet, at one corner) which discharges a
capacitor through a 1-turn coil around one side of the tablet. This
causes a magnetic pulse to propagage down metal wires across the tablet.
IIRC, it sets up magnetostrictive strains in the wires, and thus
propagates essentially at the speed of sound.
The pulse is detected by a coil in the pen/puck, and fed back to the
control electronics. The microcontroller, aided by some external
counters, measures the time delay, and thus works out where the pen/puck
is on the tablet. The process is then repeated for the other axis of the
tablet using a coil and wires at right angles to the first one.
If you want to know how I discovered all this, well, <mumble> years ago I
obtained an Apple Graphics Tablet. This is a Summagraphics tablet without
the electronics, but with the counters, etc, on an Apple ][ plug-in card.
Not having an Apple ][ at the time, I made an interface, loosely based on
the Apple ][ card (the schemaitc is in the manual) to plug into my CoCo.
After sorting out noise problems due to common ground leads (to tie into
another thread!), I got it working fairly well..
I have the Bit Pad 1 on my PERQ, and a somewhat older one, based on the
same principles, on the I2S systems. I have all the manuals and
schematics, and they all work in much the same way.
My tablet's got both a pen and a puck; maybe that's a pen connector?
On the BP1, the pen and puck plug into the same 7 pin DIN connector
(allowing for 4 buttons on the puck).
-tony
8:32 p.m.
Basically, the microcontroller triggers a thyristor
(SCR) on the
tablet driver PCB (actually iside the tablet, at one corner) which
discharges a capacitor through a 1-turn coil around one side of the
tablet. This causes a magnetic pulse to propagage down metal wires
across the tablet. IIRC, it sets up magnetostrictive strains in the
wires, and thus propagates essentially at the speed of sound.
I'm not sure how accurate this is for the pad I have.
The pad is a two-layer PCB, with the working area covered by a grid of
printed-circuit "wires", in one direction on one side of the PCB and
the other direction on the other side. They are surprisingly far
apart, on the order of ?". I haven't traced the circuitry enough to
know how accurate your description is, though I didn't see anything
like the one-turn coil you describe - everything electrical, besides
the serial connector, power, and the puck, is on the PCB. Two parallel
etch runs could form a one-turn coil; I don't recall seeing them, but I
also wasn't looking for them.
Perhaps when I open it up to investigate the DIP switch banks I'll be
able to tell.
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6 May
6 May
1:57 p.m.
Basically, the microcontroller triggers a
thyristor (SCR) on the
tablet driver PCB (actually iside the tablet, at one corner) which
discharges a capacitor through a 1-turn coil around one side of the
tablet. This causes a magnetic pulse to propagage down metal wires
across the tablet. IIRC, it sets up magnetostrictive strains in the
wires, and thus propagates essentially at the speed of sound.
I'm not sure how accurate this is for the pad I have.
The pad is a two-layer PCB, with the working area covered by a grid of
printed-circuit "wires", in one direction on one side of the PCB and
the other direction on the other side. They are surprisingly far apart, on the order of =BE". I haven't
traced the circuitry enough to
know how accurate your description is, though I didn't see anything
like the one-turn coil you describe - everything electrical, besides
the serial connector, power, and the puck, is on the PCB. Two parallel
etch runs could form a one-turn coil; I don't recall seeing them, but I
I was assuming this was a magnetostrictive tablet, like the older
Summagraphics ones. Obviously not.
-tony
7 May
7 May
9:49 p.m.
Oh, it's a Kriz tablet (after Stan Kriz at 3
rivers).
I have never fully understood how they work either.
The 'wires' in
the PCB carry electrical currents, and are sequenced in some way by
the microcontroller. The puck/pen contains a pickup coil, the output
of which is amplified and fed back to the microcontroller.
[...]
And the resolution is _much_ higher than the spacing
between the
'wires'.
Much. The manual documents resolution settings as high as 20 counts
per mm; experimenting with it, I find it actually includes settings
that appear to attempt 1000 lines/inch and 1000 lines/mm, based on
dividing full-scale counts by pad size (in-my-head estimates; I could
be out by a factor of two or so). Of course, I doubt it's accurate to
anything like ?1 count at those settings. :-)
Actually, it's not accurate to ?1 count even at the documented
settings. I find that when I turn on stream mode and don't move the
puck, I get a stream of identical samples. If I turn on request mode
and request reports (at human typing speeds), I get identical reports -
but they are a few counts different from the reports I get in stream
mode. I conjecture that there is some kind of residual carryover when
doing two readings in quick succession, as stream mode does....
One day I'll disassemble the microcontroller ROM
and make sense of it
all...
Mine has a 27xxx-series UVEPROM (2732, I think it was), and it's
socketed. I'm very tempted to pull it and dump it, and see how much of
a schematic I can extract from the pcb (the only real problem is
component-side etch runs that run under components).
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8 May
8 May
5:06 a.m.
On Sat, 8 May 2004, der Mouse wrote:
Most likely the relative signal levels of the 2 closest wires to the puck are
measured and the position is then interpolated...
Peter Wallace
Oh, it's a
Kriz tablet (after Stan Kriz at 3 rivers).
I have never fully understood how they work
either. The 'wires' in
the PCB carry electrical currents, and are sequenced in some way by
the microcontroller. The puck/pen contains a pickup coil, the output
of which is amplified and fed back to the microcontroller.
[...]
And the resolution is _much_ higher than the
spacing between the
'wires'.
Much. The manual documents resolution settings as high as 20 counts
per mm; experimenting with it, I find it actually includes settings
that appear to attempt 1000 lines/inch and 1000 lines/mm, based on
dividing full-scale counts by pad size (in-my-head estimates; I could
be out by a factor of two or so). Of course, I doubt it's accurate to
anything like ±1 count at those settings. :-) 
7:46 a.m.
New subject: free: CIE CIT-101e User's Manual
Have one of these terminals? Get the manual.
Good appendices, illustrations, etc. Perhaps 200 pages.
Get it before it goes to epay.
John A.
5 May
5 May
2:34 p.m.
I have the thing opened up right now. There are 24 DIP switches, three
banks of eight, labeled SW1 through SW3. The settings currently are
Eeek!
thus, with bits numbered according to the markings on
the switch banks
and 1=on, 0=off:
12345678 <--bit numbers
SW1 11110110
SW2 11000010
SW3 10110110
There is a good deal of "small" logic, CMOS and TTL in the cases I've
bothered to look at the numbers on, a bunch of discrete components, and
three socketed "big chips": a 2732 UVEPROM with a sticker on which is
handwritten "1103" and "7.9"; a 74C154 (why this is socketed I have
no
idea); and something that looks like a CPU, on which is printed various
things in various ways; I think it's probably an 8031.
Possibly. The Bit Pad 1 used an 8035. And, IIRC a 2708 EPROM. It was
certainly a 3-rail thing, since one the problems with one of my BP1s was
that the PSU stopped giving the -5V output, the EPROM couldn't be read,
and the microcontroler did nothing useful...
There's also a momentary pushbutton switch of no obvious function
(inaccessible with the cover on) labeled SW4 and a six-contact
The BP1 has a reset button, but that's accessible without dismantling the
thing.
card-edge connector of equally obscure function.
No idea. PSU input?
-tony
7383
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7387
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22 comments
8 participants
participants (8)
-
allain＠panix.com -
ard＠p850ug1.demon.co.uk -
coredump＠gifford.co.uk -
gerold.pauler＠gmx.net -
jcwren＠jcwren.com -
julesrichardsonuk＠yahoo.co.uk -
mouse＠Rodents.Montreal.QC.CA -
pcw＠mesanet.com