Reviving DEC RX01 power supply
Jerome H. Fine
jhfinedp3k at compsys.to
Fri Sep 7 13:46:06 CDT 2007
>Ethan Dicks wrote:
>My first -11 hard drive controller was an RLV11 that ran me about
>$100. I dropped into a BA-11N w/KDF11, DLV11J, MSV11-mumble (M8044),
>and LPV11 that all ran me $300 in 1986. I borrowed a VT220, an RL01,
>and an LA180 from my main PDP-8/a, I made a living on that -11 for
>almost two years. I still have it in a slightly improved form (I
>upgraded the backplane to 22-bit and threw more memory into it). I
>ran RT-11 v5.something on it for years (5.3?) Very nice system, but
>so is the OP's 11/03 w/floppy.
Jerome Fine replies:
I seem to remember that my first (i.e. not the system I used at work
a VT103 with a PDP-11/23 inside and a DSD 880/8 floppy / hard drive combo.
The latter was an 8 MB RL01 emulation combined with RX02 (actually RX03
although DEC never released their version) 1/2 MB SSDD 8" floppy emulation.
I seem to remember V04.00 of RT-11.
The floppy served as the backup, but I found the floppy far too slow to
useful as compared with the hard drive. Plus, with only the single
it would not have been possible to save files, etc.
>RT-11 works fine on a floppy-only system. It works *great* on a
>hard-disk system. It was one of my favorite environments before I
>managed to scrape together my first UNIX system a few years later.
I agree that if someone had a dual RX02 floppy system without
a hard drive, useful work could be done but much more slowly.
I also seem to remember that the VT103 backplane was upgraded
to 22 bit memory support and a Sigma RQD11-B MFM controller was
briefly added to the backplane to support a Seagate 10 MB hard
drive (was actually an old DEC RD51) that somehow was squeezed
in beside the power supply.
At one even shorter period of time, the VT103 backplane had a
PDP-11/73 quad CPU, 4 MB of memory, DHV11 and a Sigma RQD11-EC
controller that supported FOUR * 600 MB ESDI Hitachi hard drives
although it was essential that all of the hard drives were placed
OUTSIDE the VT103 since each required its own fan and all of the
hard drives and their fans also used a separate external power
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