20 May
2013
20 May
'13
1:49 p.m.
On 05/20/2013 03:12 PM, Ethan Dicks wrote:
Actually thats not much of an issue. For the PDP-8 and serial mass storage
case it's easy no one(save maybe me) is using a real TU58 so the protocol
"tuned" for PDP8 is up to the designer. Things like a simple boot loader
and simplified block addressable packet protocol is not difficult. The
real trick
is a one page driver to OS/8.
On Sat, May 18, 2013 at 6:39 PM, allison <ajp166 at
verizon.net> wrote:
This is true, though small boards are getting real
cheap.
On 05/18/2013 04:50 PM, Dave McGuire wrote:
Indeed. For
$35, the Raspberry Pi gives you a 3.3V serial port (just
add one chip to do level shifting), plenty of local file store for
disk or tape images, and enough I/O lines to implement an
LCD/push-button interface.
Yebbut...having a grand old system like a
PDP-11 on "life support" by
connecting it to a PC is something that I (and others) find extremely
distasteful. A standalone device would definitely have a market.
I agree.
Besides a whole pc is wasted. All that is needed is a Beagleboard
or RaspberryPi running linux and the TU58 emulation for two drives. Heck an 8051 can do that (see spare time gizmos
tu58em)!
Yep, but building a solution around a Raspberry Pi is a lot cheaper
than rolling your own board. A more modern
version could easily put a 8gb micro SD effectively at the end
of a serial port... a serial board is the easiest thing to build for PDP8...
My
memory was that back in the day when the TU58 was new, the PDP-8
community was very excited about inexpensive block-addressable storage
but it came to naught because the TU58 RSP protocol relied on "break"
to synchronize the host and the drive and it's not easy to send a
break from a pre-DECmate serial port. I remember a lot of discussion
published in LUG newsletters, but I don't think anything was every
produced in the way of an OS/8 driver. Serial ports and PDP-8s and Kermit certainly go well
together.
PDP8 and anything serial. It was also the easiest bus to hack devices
for.
Allison
-ethan