>Bob Shannon wrote:
> RT-11, the DSD boxes cannot use stock DEC drivers.
Jerome Fine replies:
I believe you are incorrect. The extra detail is as follows:
The DSD boxes can use BOTH the hard drive (emulating
an RL01 for the 8 MByte hard drive or 3 * RL02 for
the 30 MByte hard drive) and the single 8" floppy drive
(emulating an RX02) with stock (distributed) device
drivers. I have done so with BOTH V4.00 and V5.03
distributions of RT-11.
I agree there needs to be a SYSGEN to be able to use
all 3 * RL02 drives with the DL(X).SYS device drivers
and the hardware handles ONLY 18 bit addresses for
both the DYX.SYS and DLX.SYS device drivers.
BUT the RLV11 and the RXV12 from DEC also
managed to handle only 18-bit addresses. So the
DSD box was completely compatible with the stock
(distributed) V4.00 of RT-11.
However, V4.00 code in DY.MAC contained the
extra instructions to use a double-sided media which
would probably have been called an RX03. And
although those extra instructions had bugs (after all
they had never been tested) and were removed by
V5.00 of RT-11, I did fix the bugs and ran a DYX.SYS
device driver under V5.03 of RT-11 using the DSD
8" floppy as a double-sided drive. In addition,
I also added a bounce buffer in DYX.SYS so that
a user buffer above 256 KBytes could be used
with the 18-bit hardware addresses in the floppy.
I would appreciate any replies, especially ones which
correct the above information and what I actually
did with the DSD hardware and the RT-11 software.
Sincerely yours,
Jerome Fine
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Received on Mon Jul 21 2003 - 22:30:01 BST