22 Aug
2001
22 Aug
'01
2:23 a.m.
At 03:37 PM 8/18/01 -0400, you wrote:
I have one of the Codar boards... it is part of the
11/73 which
used to run the heating/cooling systems at the DEC mill complex.
The TOY-11 has a copyright date of 1983 on the board and the ic's have
date codes for 1986. Isn't old good!
If you can check the battery and replace it if needed,
put it
in a qbus machine and see how many registers there are after 176600
(open 176600 and then simply hit <LF> until it complains).
I used the MAP function in my 11/23+ boot rom to find the registers, there are
two used by the TOY-11. 176670 and 176672.
Keep track of the contents and see if they correlate to
the
current date/time... keep in mind the registers may have the
info in BCD...
In fact... I just found some datasheets for the chip on the web and
can see that the info is in BCD... and it is in successive registers
on the chip... the question is whether the qbus board implements
a direct one-for-one relation to the chip registers or if there is
a control register used as an index (write the register number to
read) and a buffer register which is read to read that chip register
and written to set that chip register.
It appears that the TOY-11 implementation is very simple. Address
176670 is write only and sets up the address code on the clock
chip. 176672 is read/write and I assume that means if you read you
get the current counter setting and if you write you set the counter.
At least that is what I have been able to do by writing codes to '670
and then reading '672.
Oh, another thing... it could be that the registers are
in successive
*BYTES*, not words.
It looks like the contents of 176672 contain a byte of data, 2 BCD digits.
Keep me informed... sounds interesting... I might be
able to help
with a program which reads the info and sets the RT system date/time
on bootup...
I'm going to look at the software for the Codar board, maybe that can be
adapted to work with the TOY-11.