27 Feb
2013
27 Feb
'13
4:33 a.m.
Hi Allison,
No flame intended but...
But?
USB is the least useful interface for PDP-8 as
it's all driver dependent and
PDP-8 is slow.
I think its a wonderful interface the way I currently use it. The
FTDI chip is
recognized as an USB serial converter. In Windows you need FTDI's standard
driver, Linux supports the chip via it's mainline ftdio_sio driver. Plug it in
and it works.
My current interface is designed to do direct transfers between the PC and the
PDP8 without too much software issues. And that's exactly what my solution
provides. There's no more simpler interface than the console TTY interface on
the PDP8 which is implemented on that side of the wire.
must USB devices do not fit into the 12 bit form well.
Console TTY is 8 bit only as well.
One that most users would want is a emulation of some
mass storage device like
DECtape or RX02, or
maybe RK05 (or 5F). This is the most often needed item,
Yes? The board is NOT (!!)
intended to replace any (probably missing) vintage
hardware. If you need an RK05 on your pdp8: Use an RK05! It is for those who
have RK05, DECtape etc. in quantities and want to be able to make quick backups
and restores to that *real* media.
Emulating a RK05 can be fun. But it's quite another approach. For making
frequent backups and restores, an SD card solution is considered quite
unpracticable - at least by me.
second only to memory
but that can be
built as semiconductor.
As above: I'm currently not talking about building
replacements for real big
iron. If you need core: Simply throw in some core memory.
To dump stuff from PDP-8 to PC a serial line is best
suited and most economical
to implement even if the host is
crippled and only has USB (use a USB to serial adaptor).
Oh, you seem to have
missed the central point.
Yes, a serial line is ideal. But slow! The board I designed is a plug-in
replacement for the PDP8's serial interface. It is software compatible and can
be plugged in without any changes in software. Most of the software (except
stuff like dumprest that makes assumptions on the expected data rate) runs with
it without *ANY* programming involved.
And on the PC side it presents itself as exactly one of those USB to serial
converters.
The only difference is that it's lightning fast and does not loose data when the
receiver stops fetching data.
Kind regards
Philipp
Allison
> It ist not meant as a console terminal replacement (which it could be used as)
> but as an alternative IO device used to dump (archive!) and restore mass
> storage media.
> To the people who don't know the problems of having MASSES of disks and tapes
> to dump: Please don't flame.
>
> Pictures and some more information can be found on my website:
> http://pdp8.hachti.de?gallery/omnibus_usb
>
> My intention is to design an improved (probably full height) version and do a
> little production run. As I'm currently out of work, selling those boards
> could help a bit. I can do it only if I get enough preorders. So I ask
> everybody with serious interest to tell me how many boards he wants and how
> much he could spend. Based on that feedback I'll decide if I can do it and fix
> a price. It won't be cheap - but very helpful and cool!
>
> I'd really like to make some more. It would be great if there's enough
> interest to do it.
>
> If you have any suggestions, let me know!
>
>
> Kind regards,
>
> Philipp :-)
>
--
Dipl.-Inf. (FH) Philipp Hachtmann
Buchdruck, Bleisatz, Spezialit?ten
Alemannstr. 21, D-30165 Hannover
Tel. 0511/3522222, Mobil 0171/2632239
Fax. 0511/3500439
hachti at hachti.de
www.tiegeldruck.de
UStdID DE 202668329