2 Jun
2011
2 Jun
'11
6:39 p.m.
Johnny Billquist wrote:
Yeah. Nothing mythical about the 6-button panel. Glad
to see that I'm
not the only one thinking so.
The 6 button front panel on the BA23 box is specifically
for when there are 2 MFM RD5n / RD3n hard drives.
For a system using all DEC hardware in an approved
configuration, the 1/2 height MFM RD3n hard drives
can be stacked so that 2 hard drives will fit in one bay.
I remember_trying_ to put two hard disks in one
machine for quick
disk-to-disk copies. I have a fuzzy memory that it didn't work for
me, but I don't remember whacking either drive to the point that they
didn't work when returned to their former homes.
As far as I know, the BA23 backplane distribution panel can *not* be
used for two disk drives. I know there is a DEC note/article about
this not working. You need the external distribution board for the
RQDX3 to use two drives. If you use the BA23 backplane distribution
panel with two harddisk drives, you have a high chance of corrupting
both disks.
(If I remember right, the write gate signal somehow goes to both
disks, no matter what, which cause the disk to possibly start writing
when the disk is seeking, for example. Very bad.) The BA23 backplane distribution should only be used
for one harddisk,
and possibly one floppy.
The BA23 box which includes an RD distribution panel supports
two hard drives and two floppy drives. The RX50 is a dual
drive in a single enclosure and counts as 2 floppy drives.
While support for 2 floppy drives is standard, support for
2 hard drives requires a 6 button BA23 front panel.
Jerome Fine