VAX-11/780 boot disk

From: ajp166 <>
Date: Fri Jan 26 17:16:52 2001

From: Jerome Fine <>
>I have been told that starting with V5.05, "the high priced spread" was
>split onto 2 RL02 cartridges with each only slightly more than half
>Which versions of the RT-11 Source distribution do you have? Also,

DEC internal copy of the source kit for 5.4. Nominally you could buy
a license for it at some really obcence price (more that 3000$). It
the better part of one RL02.

>I missed something - or I just don't understand what you are getting at.
>What was partitioned - RD52 or RL02 or a much bigger drive? And
>I also don't know if "run" means "boot" or something else.

The RD52 into 3 10mb "RL02s" as virtual images.

>I tried the TK50 - ONCE. Since I do a verify on any backup tape 99%
>of the time, anyone who has tried to do a BUP verify using a TK50
>vs a hard disk will understand. While it took about 19 minutes to write
>one 32 MByte RT-11 partition, it was over an hour during the
>"/VERIFY:ONLY" operation that I gave up.
>Now the TK70 (which uses the IDENTICAL DLT tape - CompacTape I)
>is another matter. The TK70 drive writes 4 times as much data on one
>tape and writes the data three time as fast and the "/VERIFY:ONLY"
>operation is just as fast as the BACKUP. So a BUP with the TK70
>can place 8.5 RT-11 partitions on one tape using a TK70.

Apparently a difference in how it handle streaming of small block sizes.
The TK50 does very poorly at writes of short blocks.

>Reliable - yes. Useful as compared with 256 MBytes - NO!

Well it doesnt require a SCSI board and I had it. If you have MO
Cool and all the better. If I had one I'd have used it.

>But if you restrict the comparison to RD51,2,3,4 drives, then
>yes!!!!!!!!!! I have had too many RD53 drives go in the last
>few years to count. Most were Micropolis 1325 drives with
>the R7 jumper inserted so that the RQDX2 thought they were
>a real DEC RD53.

Which is a M1325! That drive was the poorest of the lot and
only a bit better than RD32 (ST251). The XT2190 (RD54) is a
good drive but like many of that type and size 31 Watts is a
lot of heat that is unhealthy over time. RD52 was the coolest
running of the pack and still fast for it size (and MFM).

>But with Hitachi DK515-78 drives and a Sigma RQD11-EC
>that handles four drives, there is not much to choose between
>4 * RD52 (= 120 MBytes) and 4 * DK515-78 (=2.4 GBytes).

Killer if you have MSCP compatable SCSI, useless with the
more common RQDX3.

>Now this is one area I would like to solve as well. But what
>OS is needed if I want to use the first 64 blocks on the CD?

With that many who cares? I'd just use it as an image copy of
the real thing. I'd have little interest in booting RT-11 from CD
as CDs most are slower than MFM! Also how would you handle
RT-11 SWAP.SYS? That has to be read/write.

Received on Fri Jan 26 2001 - 17:16:52 GMT

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