VAX 11/730 quickie

[Mike Ross]

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

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