[Simh] Questions regarding future simulator development

[Johnny Billquist]

On 2013-04-11 02:13, Christian Gauger-Cosgrove wrote:
> Hello Mark,
>
> On 10 April 2013 13:37, Mark Pizzolato - Info Comm <Mark at infocomm.com> wrote:
>> Once again, anything is possible, but this would be a significant amount of work.   If there was some formal documentation available which described the RS03 and RS04 disks, then adding them to the pdp11_rq.c code would probably not be too hard.  Looking in the 'usual places' on bitsavers.org doesn't provide any information on these disk devices though.
>>
> Well it would be to the pdp11_rp.c code, but either way, they're just
> another form of MASSBUS disk, and in my quick browse through the
> pdp11_rp.c code, it looks likes like the various drives under its
> purview are only defined as their geometries. So to add the RS03 and
> RS04, all that would be needed to be added -- in my quick glance at
> the code, would only require entering the proper geometry for the
> devices.

There exists a couple of different types of Massbus disks, but I suspect 
adding RS03 and RS04 would be very easy.

>> Meanwhile, there already exists support for many disks within the current simh codebase.  There is existing support for 4 RQDX controllers each of which can support 4 drives.  The RL controller can support up to 4 drives.  The RP can support up to 8 drives.  The HK (RK611) can support up to 8 drives.
>>
> Speaking of the RK611, I noticed a problem, whereby an RK07 errors out
> in RSTS/E (10.1-L) with "device not ready" or something similar, while
> it works just fine with an RK06... weird.
>
> There is only one set of drives that isn't implemented in SIMH at
> present, is the pre-MASSBUS RP drives (on the actual RP11 controller,
> so RP01, RP02 and RP03). But I don't think much if any still extant
> software even supports the RP0[1:3].

RSX still supports them, and I suspect the same is true for RSTS/E and 
RT-11, but I haven't checked. In RSX, it is the DP: driver.

But I don't know if all various types of disks that ever existed for 
PDP-11s really are implemented in simh.

	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