On Jan 16, 2016, at 12:15, tony duell <a...@p850ug1.demon.co.uk> wrote:

> I had considered that, or one of the TU58 emulators that use SD cards or 
> similar but (a) I am trying to restore this VAX, not make a machine that runs
> VAX software and is not original and (b) I do have this moral objection to 
> using more components to load the microcode than in the rest of the machine.

I am in that same camp. I am presently using TU58 emulation to make progress on 
the rest of the system, but I do plan to try to get my original drive and tapes 
working in the future. Even if I immediately unplug it and plug an emulator 
back in, because I thoroughly distrust the tape cartridge design and I am not 
confident that any of my tapes are any good. I would like to make an SD card 
based emulator that clicks into place in one of the tape slots and the plugs 
into the console I place if the original drive, so it can be as unobtrusive and 
standalone as possible. 


> 
> AFAIK the TU58 interface (at least on the 11/730) can run at RS232 levels, you
> don't need a level shifter board.

Correct. Regular RS232 levels. There is at least one really short timeout in 
the console code that can cause trouble with some emulators running on some 
platforms, but I managed to hack around that in tu58em running on a Mac. I put 
together hardware to use a RasPi instead so the 730 doesn't need to be tethered 
to a laptop, but I haven't gotten that working yet. 


> This, alas, means I am not going to have 
> ethernet since AFAIK you can't run the cable through that odd cable tray 
> thing on
> the 11/730.

I have Ethernet in my 730, though I don't have it working yet. My experience is 
that trying to route the round AUI cable through the bottom tray with the 
ribbon cables is doomed to failure, but the cable can instead be routed over 
the top of the cards, through openings in the power supply area, then along the 
folding gantry along with the power cables. I haven't gotten networking up and 
running on my VAX yet, and I don't yet know what combination of hardware, 
software and operator ignorance is causing it to not work.  I'm still pretty 
happy that I can boot VMS from either the R80 or RL02. 


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