Re: Membership Card PCB design
- So are you saying you want to have a different board than the current
front panel board and it would replace that board so it still fits in
an Altoids tin? (sorry if I'm slow on the uptake)
You could just use a ribbon cable with a connector on the end and
plug that into a plug on your board. (as opposed to a "hard connector"
that is soldered onto the board) That would give you the other signals.
I think that's probably how I would do it. And then you would just
not use that cable-connector when you had the front panel plugged in.
Or if it's a "separate product", then it doesn't matter either way.
That way you don't have to design or create a new board and it all fits.
- I've been using it in mode 1 thinking it was most compatible with the 1802 that way. I'll try mode 0. Thanks as always.
Date: Fri, 6 Jan 2012 19:21:05 -0600
Subject: Re: [cosmacelf] oops the CDP1854
On 1/6/2012 6:32 PM, bill rowe wrote:
> I've been experimenting with my fine new UART looping transmit to
> receive but I kept sending 0xFF and getting back 0x1F.It looks to me
> like the 1854 defaults to a mighty 5 data bits - perfect for that
> baudot terminal I've been wanting but not much good for cold-loading
> the 1802 via DMA! I'm going to carefully read the datasheet again but
> the USB->8 bit parallel thing is starting to look more interesting.
Remember that it's a CMOS chip. All inputs have to be tied to ground or
VCC; leaving them floating will cause unpredictable results!
Are you using it in mode 0 (6402 compatible) or mode 1 (1802 bus
In mode 1, you need to initialize the control register from the 1802 bus
with the number of bits you want (and other parameters).
In mode 0, the inputs to the control register are all on external pins
that you hard-wire to VCC or GND to determine the data format. The word
length is set with the word length select input pins:
WLS2 WLS1 Word
pin 37 pin 38 Length
------ ------ ------
0 0 5 bits
0 1 6 bits
1 0 7 bits
1 1 8 bits
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Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart at earthlink.net
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