[Simh] Rainbow100

[Johnny Billquist]

On 2017-07-20 18:58, Paul Koning wrote:
>
>> On Jul 20, 2017, at 11:31 AM, Ray Jewhurst <raywjewhurst at gmail.com> wrote:
>>
>> The DECPro 3xx series (same era I do believe ) is much more interesting than the Rainbow IMO. It runs with either a Fonz or a Jaws (PDP-11 on a chip) It's OSes are POS, a RSX-11M-PLUS derivative, RT-11, 211BSD and Venix, a Unix System III. Good news is there is an old emulator for it called xhomer which you can get at xhomer.isani.org. Also, it does build well on Ubuntu. Not sure on other distros. There is also a fair amount of documentation on Bitsavers. It may be worth looking into.
>
> xhomer is an ancient fork of SIMH with a license problem (hard conflict between the SIMH license on that version and the GPL intended to apply to the PRO mods).  I've tried to see if this can be cured by replacing the GPL, so far no luck though I did get one or two encouraging responses.  It would be good to merge it into SIMH.  Failing that, I suppose a new implementation would (done within SIMH) could be done; the PRO isn't all that hard and the Technical Manual on Bitsavers has most of the answers.

GPL can be such a headache.
I could perhaps be persuaded to help out some, if you go for 
reimplementing this, Paul.

> I've been wanting to add to the PRO emulation, stuff like Ethernet, or the obscure PC3XC 4-line UART card, or PRO-380.  But right now there is no place to do that.

The single most annoying thing about the PRO (well, of course there are 
so many with this machine) is the crippled state of the PRO-380. Here 
you have this nice J11 CPU, and then they still have the same support 
chips as on the 350, meaning you're running at a slow speed, and with 
P/OS you cannot use the split I/D-space, nor the supervisor mode.
Not sure if it would work ok if you did your own software.
Also, since the device drivers for the PRO specific things seems to have 
gone missing, I have no idea if it would be possible to build a new 
version of P/OS which could take advantage of the -380 hardware, but 
I've been peeking a little in the RSX sources about this a few times...

If only DEC had made that machine like a normal PDP-11...

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol