VAX 11/730 quickie

Mike Ross tmfdmike at gmail.com
Wed Feb 24 05:43:57 CST 2016


On Tue, Feb 23, 2016 at 4:26 AM, Mike Ross <tmfdmike at gmail.com> wrote:
> On Mon, Feb 22, 2016 at 10:14 AM, Mark J. Blair <nf6x at nf6x.net> wrote:
>>
>>> On Feb 21, 2016, at 23:09, Mike Ross <tmfdmike at gmail.com> wrote:
>>> Actually I do have a Mac within easy range of the 730. Could you do me
>>> a favour and throw a prebuilt OSX binary somewhere I can grab it? I
>>> have flaky internet in the workshop and this Mac isn't set up with
>>> Xcode or any other dev environment...
>>
>> https://dl.dropboxusercontent.com/u/29876211/tu58em.zip
>
> Thanks Mark... I played with this. I built a 3-wire cable; I'm sure I
> have it wired right because traffic happens - and if I disconnect, or
> switch Rx/Tx, it just sits there.... but this is as far as it gets:
>
> MikeUpstairs:~ Imac$ ./tu58 -s 38400 -p /dev/tty.usbserial -d -v -m -x
> -r vax73058
> info: unit 0 r    file 'vax73058'
> info: tu58 tape emulator v1.4j (NF6X fork)
> info: (C) 2005-2014 Don North <ak6dn at mindspring.com>, (C) 1984 Dan
> Ts'o <Rockefeller University>
> info: serial port /dev/tty.usbserial at 38400 baud
> info: MRSP mode enabled (NOT fully tested - use with caution)
> info: TU58 emulation start
> info: R restart, S toggle send init, V toggle verbose, D toggle debug, Q quit
> info: emulator started
>
> (I ctrl-c the VAX)
>
> info: flag=0x00 last=0x00
> info: <NULL> seen
> info: flag=0x00 last=0x00
> info: <NULL> seen
> info: flag=0x04 last=0x00
> info: <INIT> seen
> info: flag=0x04 last=0x04
> info: <INIT> seen
> info: <INIT><INIT> seen, sending <CONT>
>
> (?27 DEVICE ERROR on VAX)
>
> (I ctrl-c the VAX again)
>
> info: flag=0x00 last=0xFF
> info: <NULL> seen
> info: flag=0x00 last=0x00
> info: <NULL> seen
> info: flag=0x04 last=0x00
> info: <INIT> seen
> info: flag=0x04 last=0x04
> info: <INIT> seen
> info: <INIT><INIT> seen, sending <CONT>
>
> (?27 DEVICE ERROR on VAX)
>
> (repeat)
>
> Can you spot me being stupid? Does my command line look sane re.
> various options?
>
> (I've trivially renamed the tape image file for faster typing
> otherwise it's straight out of the box)

Just for giggles I decided to try Bela Torok's Arduino-based emulator:

http://www.torok.info/computing/pdp11/tu58/

I whipped that up from bits tonight and got it working surprisingly
quickly. But the VAX still doesn't want to play; from the behaviour
and messages it's falling over at exactly the same place. The Arduino
serial console displays:

Continue after 2 INIT flags. online!

And VAX shows the now-familiar ?27 DEVICE ERROR...

Which looks a HELL of a lot like how tu58em is ending. So I don't
think the problem is with tu58em...

Is there anything I should be looking at on the VAX end here? Any
configuration or cabling details that could be screwing things up
before I drag the RS232 analyser out? I've tried changing the 'delay'
parameter on the Arduino to various values between 0 and 255 to no
avail - and I've tried a couple of different tape images in case I got
a bad one...

Mike

http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'


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