4 Jul
2014
4 Jul
'14
2:30 p.m.
Sorry about the late reply. This letter ended up in my Gmail spam folder
for some reason.
That's brilliant Dave, It means I do have the board configured correctly.
No worries about the PSU. I've got two in C4P.
My systems telling me I have 18687 bytes. Obviously a crook RAM chip
somewhere.
Terry (Tez)
On Thu, Jul 3, 2014 at 3:14 AM, Dave <dfnr2 at yahoo.com> wrote:
Thanks Dave, I thought that might be the case. I was trying to find how to
RAM
set the jumpers (marked W1, W2, W3) in the board
so I could set the
RAM addresses to use it with an 8k 502 board.
It looks like the default jumper setting is set up for use with an 8K 502
board.
The '138 at F9 decodes A13-A15 to provide 8 selects corresponding
to 8K blocks. By default, the mapping is
W1->F9 pin 14 (Y1 = $2000)
W2->F9 pin 13 (Y2 = $4000)
W3->F9 pin 12 (Y3 = $6000)
which allows the 8K block at $0000. If you had a 505 board and one 527,
you'd move W3 over to the Y0 output on pin 15 of F9 ($0000), and have a
solid block from $0000-$5FFF.
Make sure, if you're adding the 527 into a system that previously only had
a 502 and 540 board, that you add a second power supply for the 527 (which
can be powered via the side power connector), or replace the original
supply with a beefier supply, because the 527 will suck a lot of current
and the single supply can't handle the additional load.
Good idea about joining the list.
We would be delighted to have you.
Dave
Terry (Tez)
On Wed, Jul 2, 2014 at 4:19 AM, Dave <dfnr2 at yahoo.com> wrote:
> Hi Terry,
>
> To more directly answer your question, for OSI, the schematics *were*
the
> manual in a great many cases, and the 527
board was one of those
cases. To
> my knowledge, OSI never published any text
such as theory of operation
or a
> troubleshooting guide to go with the
schematics for this board.
Luckily,
OSI
designs tended to be simple and robust, and easy to follow.
Dave
On Monday, June 30, 2014 6:25 PM, Terry Stewart <terry at webweavers.co.nz
> wrote:
>
>
> >
> >
> >The title says it all. I'm looking to repair/configure a OIS 527 24k board for my Challenger 4P. Anyone have or know of the
existence of a
manual for this board?
Thanks
Terry (Tez)