Thanks Dave, I thought that might be the case. I was trying to find how to
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 RAM
board for my Challenger 4P.? Anyone have or know of the existence of a
manual for this board?
Thanks
Terry (Tez)