27 May
2013
27 May
'13
10:02 a.m.
blstuart at bellsouth.net wrote:
So I decided to write a TU58 emulator for my 6809 SBC
to serve "tapes"
from an SD card. So far, I've only implemented a first version of the
read side. It seems to work on an XXDP image I found online.
However, when I try to boot an RT-11 tape image, I get:
@1000G?BOOT-W-Error reading handler
?BOOT-W-Error reading handler
...
?BOOT-W-Error reading handler
RT-11SJ V04.00A
?BOOT-W-Invalid or missing TT.SYS
?KMON-U-Overlay read error
.
.SHOW
?KMON-U-Overlay read error
Any ideas on what might be causing this? I've dug up the old rtpip
code and gotten it partially working in a more current environment,
and it seems to be happy with the tape images I have. I've had this
happen on two tape images. Also the original tapes from which these
images were made are ones that I've booted from (after I made the tape
images), albeit over 20 years ago. So it looks like either something
strange in my tape images or something in my emulator that works to
load the secondary boot, but fails for loading some other parts of the
tape.
My first reaction is that the most likely problem is the
RT-11 image on the emulated TU-58. If you can
read the files on that image, there may be nothing wrong
with the emulation. What may be the problem is that
you RT-11 image on the emulated TU-58 tape is
missing the file TT.SYS and is giving those error
messages as a result.
Can you obtain another RT-11 distribution and copy it
to the emulated TU-58 tape image? After you do that,
you will need to:
COPY/BOOT DD0:RT11SJ.SYS DD0:
to make the emulated TU_58 tape image hardware bootable.
Otherwise, if that is not the problem, additional information
will be needed.
Jerome Fine