On 15-Dec-17 22:14, khandy21yo wrote: > Can't you just load them into ram and run them from there? > Rom is just non writable memory. > > He could, except that these ROMs are probably in I/O space, so would need to be part of a simulated device for any code to execute properly[1]. (And any code in them probably touches the device registers, so you need the device to get anywhere.) As Mark pointed out, SimH doesn't currently support any devices that way - it does functional emulation of I/O devices. (It wouldn't be difficult to write such a device emulation if there were a reason to.)
However, to disassemble code/view data, they could be loaded into any RAM address & poked at with the SimH console. Some reformatting would be required, since ROMs of that era would typically be byte-wide, with 2 devices/word - e.g. one ROM contains the even bytes, another the odd ones. (There are other organizations.) FWIW, ROMs in I/O devices tend to be one or more of: * Code for on-board processors (rare in early PDP-11s, but Ethernet and (t)MSCP boards had them) * Identifying data for the device (e.g. device type, model, serial, timing, geometry, etc) * Bootcode/self-test/primitive driver for the host to execute * Data for the host (e.g. Fonts or strings) However, as Aaron says that the devices have been erased, it's all moot at this point :-) So that's probably more than you wanted to know... [1] While the code would likely be PIC, things like references to the device's registers would also be relative to where the code is loaded. Looping on a "done" bit relocated to RAM is likely to be frustrating... > > Sent from my Galaxy Tab® A > > -------- Original message -------- > From: Aaron Jackson <aa...@aaronsplace.co.uk> > Date: 12/15/17 10:37 AM (GMT-07:00) > To: Mark Pizzolato <m...@infocomm.com> > Cc: simh@trailing-edge.com > Subject: Re: [Simh] Custom ROMs on PDP-11 sim > > Hi Mark, > > It probably does not matter anymore unfortunately. I have a PDP-11 from > a Unimation PUMA robot, which has a 16x EPROM board in it but no power > supply. I was hoping to try running what was on them inside a > simulator. I started dumping them and realised that they have all been > erased before it was sent to me. > > Of course I could have tried installing the card in my PDP-11/73 but I > thought there might have been an easier way with the simulator. > > Never mind, thanks anyway. > > Aaron. > > > > > > Mark Pizzolato writes: > > > Hi Aaron, > > > > On Friday, December 15, 2017 at 7:18 AM, Aaron Jackson wrote: > >> I am wondering if it is possible to use attach ROM dumps in the > PDP-11 simh? > >> I haven't found anything about it in the documentation. If not, I > suppose it > >> wouldn't be too hard to modify the bootrom header. > > > > The PDP11 simulator (which simulates MANY different PDP11 models) > doesn't > > actually use any ROMs and doesn't currently support simulation of > any cards > > which user supplied ROMS might have been installed in. > > > > What problem are you trying to solve??? > > > > - Mark > > > -- > Aaron Jackson > PhD Student, Computer Vision Laboratory, Uni of Nottingham > http://aaronsplace.co.uk > _______________________________________________ > Simh mailing list > Simh@trailing-edge.com > http://mailman.trailing-edge.com/mailman/listinfo/simh > > > _______________________________________________ > Simh mailing list > Simh@trailing-edge.com > http://mailman.trailing-edge.com/mailman/listinfo/simh
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