20 Jan
2009
20 Jan
'09
10:59 p.m.
(SPC slot)
If the heads load and then the CPU halts on 000004, it might mean that
it can not read the first sector, or reads garbage. If the drive works
fine as RX02 ... is the floppy that you use as an RX01 formatted?
If the disk is RX02 formatted, you will certainly get read errors in
RX01-mode. The headers on RX01 and RX02 are identical, but the data in
each sector is NOT!
Hmm, that is a good point. I was fairly certain it was an RX01 disk but
its not got any labelling on it to positively identify it as an RX01 or
RX02 disk.
I don't suppose anyone (I'm in the UK) has a RX01 disk with a bootable
XXDP or RT-11 on it that I can borrow to test with?
You can look at the backplane and check if the CA1 pin
is connected to
CB1 in the "RX11 SPC slot". If it is not, I would suggest to NOT to work
on the backplane, but check the RX11 board if those two contact fingers
are connected by a trace on the board itself. If it is not, solder a
jumper wire on the board, not on the backplane. Some older SPC boards
which are not "DMA" have a jumper wire, some not "DMA" boards do not
have the jumper, so it must be on the backplane.
Thanks for that. Will have a look and put a wire across if necessary.
Best regards,
Toby
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