23 Nov
2012
23 Nov
'12
6:31 p.m.
On 11/23/2012 08:40 PM, Eric Smith wrote:
Chris Elmquist wrote:
Wishful thinking.
I've disassembled the firmware its not there. It's not that hard to do
the reason I say modded is the 8085
has only has 256bytes of ram and 2k of rom on the board. So bypassing
the 8085 or extending the memory
and firmware by modding the board for more rom space and maybe ram space
could make the needed
formatter. In the end you need the TU58 board for the drive interface
and motor control.
TU58 core:
8085 at 2.4576mhz (4.9152 crystal), 8155 (22 io lines, timer used for
various timing needs), 2K rom,
64s004 ART (serial).
Bob at Spare Time Gizmos did a TU-58 emulator using ram devices and
DS5000 (8051 like) CPU back around 1995.
It's still the way to go save for flash is now available. I'd buy two
in a heartbeat now.
Allison
I do have some DC100A that are not DEC labeled.
They are just Scotch
(3M) brand and have a hand written "DEC" paper label stuck to them.
This suggests to me that someone had a method for formatting them.
Other labeling on the tapes suggests VAX 4500 (?) may have been
involved so I wonder if it was possible to format raw DC100A on some
flavors of VAX?
It is remotely possible that there's an undocumented "format" command
in the protocol. However, I've heard multiple people claim that
special firmware was required.
As far as I can tell, the TU58 drive hardware should be perfectly
capable of formatting a tape, unlike e.g. disk drives that use
embedded servo.