[Coco] [coco3] upscan video converter

[RJRTTY at aol.com]

       Attached is a diagram of  the basic configuration for the upscan
converter I'm building and I present it here for your approval/rejection/
vilification/ridicule/etc... given the recent flame activity on the list 
lately
I'm hoping for the best.  :)

        The converter will consist of the Avelogic AL875  high speed
ADC to digitize the RGB video output of the coco3.   From there,
the digital video is input to the Averlogic AL250 upscan converter.
This will transform the digital signal back into an analog video
signal with a scan frequency of 31 Khz compatible with all
SVGA capable monitors.     The board signals will be line locked
with an ICS1523 programmable video clock synthesizer and line
delay.

       On board programming functions will be performed by the
ATMEL ATtiny12 microcontroller.    The three above video
chips are programmable via an I2C interface.  The ATtiny12
microcontroller will be programmed itself to interact with
the I2C bus.
        One function of the ATtiny12 will be hardware and
power up resets.    Whenever there is a hardware reset, the
microcontroller will set the registers of the three video chips to
coco3 specific default values.    The converter will do a hardware
reset with the push of the reset button on the enclosure or when
directed to do so by software command on the I2C bus.
A power up reset will also result in having all registers
either set to coco3 specific default values or to a list of
programmable values depending on the choice of the user on
power being initially applied to the converter.
A "simulated" power up can be also be performed
by software command on the I2C bus.

        Another function of the controller includes a software controlled
standby power down of the monitor.

         I have sent a proto type of the converter to Torsten Dittel for
evaluation of the Averlogic video chips and use with PAL systems.
The use of the coco3 RGB video cable to transmit I2C signals was
his idea and represents a great contribution to the project.    The use
of the ATMEL ATtiny12 controller was also the idea of someone
on this list tho I cant remember thier name at the moment.  Sorry.

        One regret I have is I could not find a way to power the
converter without using a wall-wart that did not involve opening the coco3
enclosure and modifying the motherboard.   Also, I have constructed
the input cable with the audio signal enabled.   This means I will
provide a sound output port on the converter.   Should I include an amplifier
and speaker?
         Someone also suggested I provide an output port for the I2C
bus in the converter for use with  external I2C devices.    Is there
any interest in this?

         So there it is.     Maybe somebody knows something I have
missed.      If so, let's hear it.    I have become quiet proficient at
using the PC board software I got from the PCB manufacturer so I expect
to come up with a more compact and cost effective design this time around.
All tho my first try at it was good enough to evaluate the concept.

         One more thing.     What do we call this device.    Anybody got a 
catchy name?

Roy

PS   sorry about using zip file.    Picture was too big as bmp
to post without Dennis' help.....
-------------- next part --------------
A non-text attachment was scrubbed...
Name: CC3CON.ZIP
Type: application/zip
Size: 2285 bytes
Desc: not available
URL: <http://five.pairlist.net/pipermail/coco/attachments/20050716/1c1fe713/attachment.zip>