| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 125.1 | The scheme of the scanner (I've not tested it) | HLDG02::VELZEN | | Thu Jun 16 1988 08:34 | 59 |
| NE555 is wired as a monoflop if pin 2 (trigger) is made low, pin 3 gets high
The time pin 3 stays high depents on the time it takes to charge the capacitor
If pin 6+7 are at a high potential the charching time will be short.
If the potential at pin 6+7 is low the charching time will be long.
+5V -----+-----------------------+------+--------------+ +5V (from joy-stick)
| | | |
\ 10K | | |
/ | \ 500 K \ PHOTO TRANSISTOR
\ | / <--+ \
/ | \ | | <-----LIGHT
| +--------+ | / | / <-----
| +---| |---+ | | /<
| | | NE555 | | | |
RTS ----+----------| |---+------+----+---------+
| | | | |
DCD ---------------| |---+ |
(RS-232) | | | |
| -| |- -----
| +--------+ ----- 10 NF
| |
| |
-------------+----------------------------- 0 V
RTS (pin 4 on RS-232 port) starts conversion
DCD (pin 8 on RS-232 port) is the output of this scheme
This routine should read in the time DCD stays high after RTS is made LOW
MOVE,W SR,-(A7) ;STORE SR
MOVE,W #$2700,SR ;NO INTERRUPTS
CLR,W D0
MOVE,B #14,$FF8800 ;SELECT PSG PORT A (PSG??)
ORI,B #40,$FF8802 ;MAKE RTS LOW
ANDI,B #$F7,$FF8802 ;MAKE RTS HIGH AGAIN
LOOP: ADDQ,W #1,D0 ;DO+1
BTST #1,$FFA01 ;DCD STILL HIGH ?
BNE LOOP ;
MOVE,W +(A7),SR ;INTERUPTS AGAIN
RTS ;READY
THE RESULT OF THE ROUTINE IS FOUND IN D0 (8-bit)
The article says that a complete scan-program can be purchased for f 59
this is about $35.
Excuses for this messy note, I haven't got too much time to type this in
(haven't got a modem)
Jan-Willem
|
| 125.2 | Another one, with free software this time | HLDG02::VELZEN | | Fri Jun 17 1988 11:06 | 10 |
| Just picked up the May issue of ST (a german magazine)
It has a scheme of a scanner (cost about $ 20 ) and a complete listing
of a gfa basic program (PD) which reads in the picture, changes
the gray-scale (it's for black and white only) etc.
The scanner (which is also mounted on top of a printer-head) is
connected to the joystick-port.
Jan-Willem
|
| 125.3 | Oops: April not May | HLDG02::VELZEN | | Mon Jun 20 1988 06:49 | 5 |
| It's not the May issue but the april issue.
It also has a joke, running the CPU at 10 Mhz, chancing a register.
That article is dated 1-april-88.
Jan-Willem
|
| 125.4 | Still aching in the fingers .. | PILOU::ANDERSEN | Relocating my way home ? | Mon Jun 20 1988 08:39 | 5 |
| Off the topic .. hihihi
You too, now we are two april-
fools in the club.
����Martin
|
| 125.5 | Real or Imaged? | RDGENG::KEANE | | Mon Jun 20 1988 09:13 | 42 |
|
Hi, Jan-Wellem and Martin,
I dont understand why you are disheartened by the "April
fool's joke"?.- There are a number of "electronics" companies selling
scanners that fit on printers just as you describe. I am sure that
the electronics in the scanner is as crude as your examples !! For
that these firms change around 150 pound sterling!.
What would be a nice design for a scanner would be to incorporate
some form of CCD Image cell, which could scan several rows of pixals
of the subject material in one pass of the printer head. The printer
could then advance the picture by a reasonable amount each row. It
might be neccessary to provide some form of averaging program, to look
at the top row of the last scan, and the bottom row of the current scan
and average or dither any differences away, to hide the joins.
I have seen these IC cells advertised in the past, and have
had a look through the old mags and pricebooks I have, but cant
find any adverts for them at the moment. Does anyone know roughly
how many cells these devices hold, and how much are they? Can the
CCD cell be used in "linear" mode?
The other interesting thought on scanners, is the diference
between a crude on/off white black scanner, and a true grey scale
device. If I remember my optics course at college, colour or grey
scale luminance is a square law, so some form of log amp is neccessary
to convert the output of a photo sensor and produce a reasonable
scale. you would then need a a-d and input interface.
There are two objectives, either to produce a picture suitable for
direct viewing on a high, med or low res screen, or to produce and
store an image for use with a very high res output medium >300 DPI
printer.
Are there many people interested in imaging???, I am interested,
and will be investigating further, when I finish my hard disk, (nearly
there now), I have had a bit of finger trouble on my part, my stupidity,
with power supplies, but I am slowly winning, soldering iron in
hand, whenever my wife allows me into the house from performing
the outside chores!!
Keep cheerful!
Pat K.
|
| 125.6 | No April joke at all | HLDG02::VELZEN | | Mon Jun 20 1988 12:24 | 23 |
| Lest get some things straight.
1) The april joke was running the cpu at 10 Mhz by setting a bit
in a secret register, it has nothing to do with the scanner's.
2) The first scanner (with the NE555) is real
3) The second scanner (with PD GFA-basic program) is also real.
My mistake to change May and April has nothing to do with the scanner.
Unfortunately I haven't got the time yet to test the second scanner
(I haven't programmed anything on the ST yet, so the second scanner
will work within less time), but when I'm leaving DEC (end of my
practical assignment) my hollidays start, so then I'll grap my
soldering iron and build those scanners.
If anyone is interested I can send them the article of the second
scanner, (remember it's in german).
Jan-Willem
|
| 125.7 | Grey Scales | DORIS::JAMES | Howard James/PSG Tech Support/Queens House | Wed Jun 22 1988 05:19 | 8 |
| I have a program (not PD but only cost �10) that decodes amateur
slow scan television and there is a grey scale on that. It seems
there are 8 true levels of grey and this program produces a further
8 pseudo levels. For an idea of what it's like I have put a .NEO
file in DORIS::DUA2:[JAMES.ATARI]HOWARD.NEO. The picture is crumby
(so was Van-Gough) as I have more work to do on the interface but
it does give you an idea of the grey scale obtainable with 4 bits.
...Howard
|
| 125.8 | Atari + nice projekts | HLDG02::VELZEN | | Wed Jun 22 1988 08:25 | 14 |
| Ha, another self-build topic, waiting for me !
Some time ago there was a scheme and software for a weather satelitte
decoder for the ST at usenet.
It produced pictures in DEGAS or in AIM format.
So now there is also activity for slow scan television.
Is this slow scan from shortwave?
How large is your decoder hardware?
What's the adress for the software?
Is this software for color only ? (I hope not)
Jan-Willem
|
| 125.9 | More SSTV info. | DORIS::JAMES | Left Handed People are Super Natural | Fri Jun 24 1988 09:04 | 16 |
| Jan Willem - Yes the slow scan is on short wave at around about
14.230 Mhz. You really need a SSB receiver to tune the sync pulses
at 1.2 Khz, Black video at 1.5 Khz and white video at 2.3 Khz. Take
the output from the speaker and convert it to RS232 level to drive
the CTS (pin 5) of the 25 way serial port on the ST.
The software is available from J&P Electronics Ltd., New Road
Complex, New Road, Kidderminster, DY10 1AL, England. Sorry to tell
you this but it is for LO RES only. That company can also provide
a lead and level converter so you don't really have to build anything
if you're that way inclined. Their tel. no. is 0562-753893 (leave
the 0 off if dialling outside England.
I am working on sample & hold, F-D and D-A to do the conversion
and drive the printer port. I'm afraid it will be the software that
will hold me up though.
Happy scanning....
...Howard
|
| 125.10 | STAD Manual tecnical info needed . | PILOU::ANDERSEN | Relocating my way home ? | Wed Jun 29 1988 10:10 | 13 |
| Anybody having a STAD manual ??
I have started building the scanner from the German magazine, and
I will also be using the software proposed in said article.
But I'm curious if the hardware I build will be supporting the STAD
programs SCAN input function.
Question goes like this:
From where do the STAD scan function expect the input ?
Greatfully yours
����Martin
|