11 Nov
2017
11 Nov
'17
2:33 p.m.
On Nov 11, 2017, at 2:42 PM, Aaron Jackson <aaron
at aaronsplace.co.uk> wrote:
I too have had home built cables cause me grief because
of confusions around pins, keying or just being cable to properly fasten the
connectors.
Could elaborate a bit on this part of your earlier message.
Aaron,
Do not underestimate the need for termination, even with a very short external cable.
When you factor in the internal cables runs, crosstalk or signal reflections which
interfere
with operation may still be present, especially when data transfers start.
If you have access to another bootable drive (8inch floppy?), suggest you load the
XXDP+ diagnostics for RL Drives.
Jerry
Hi Jerry, thanks for the information.
I had built several terminators, but being terrible at geometry I always
did something wrong. I have now fixed one of the terminators I built. I
had pins 1 and 40 mixed up, the rest of the terminator is basically a
mirror copy.
Unfortunately I still have the same error.
I have an RX02 drive but no controller yet, so I'll have to continue
investigating in the dark.
Thanks,
Aaron. I managed to boot into XXDP today using tu58em and ran
the RLV12
controller test. It seems though that the version of XXDP I loaded does
not support the 22bit address (17774400) and defaults to the 16bit
address (174400) so it just shows errors for everything.
VRLBCO expects 16 bit addresses for hardware setup. Most of the
XXDP diagnostic programs understand the 16 bit address for IO page
type devices.
Separately, if this diagnostic itself is not able to use 22 bit memory
on an 11/73 with 1MB ram, then you may have other issues. It
should not be tossing errors. The fact that XXDP cannot boot
into extended addressing (XXDPXM) is not a good sign either.
Jerry