[Simh] CDC1700 simulator update

2017-12-16 Thread John Forecast
I’ve updated the CDC1700 simulator to include: 1. Support for the 1752 Drum controller with capacities from 192KB to 3MB 2. Implement the ability to share subroutines between interrupt service routines at different priorities. 3. Implement a number of Simh expect

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Christian Gauger-Cosgrove
On 16 December 2017 at 19:20, Tim Stark wrote: > Well, there are some PDP-11 tech docs indicates that higher models like > 11/53, 11/73, 11/74, 11/83, 11/84, 11/93, and 11/94 have built-in own > firmware ROMs at starting 16 with switch bits for banking. > Don't include

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Tim Stark
Folks, Well, there are some PDP-11 tech docs indicates that higher models like 11/53, 11/73, 11/74, 11/83, 11/84, 11/93, and 11/94 have built-in own firmware ROMs at starting 16 with switch bits for banking. Tim ___ Simh mailing list

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Timothe Litt
On 16-Dec-17 15:42, Paul Koning wrote: > > >> On Dec 16, 2017, at 6:14 AM, Timothe Litt > > wrote: >> >> 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

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Johnny Billquist
On 2017-12-16 23:32, Timothe Litt wrote: On 16-Dec-17 16:38, Johnny Billquist wrote: However, such a device would be wrong to start with. And I've never seen anyone do that, but sure, it could be done. Read the OP.  He has such a device.  It has ROMs with PDP-11 code -- or at least,

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Johnny Billquist
On 2017-12-16 16:21, Timothe Litt wrote: On 16-Dec-17 07:35, Johnny Billquist wrote: Top-posting to make it simple, while still keeping the original text. While it is true that device access might be done using relative addressing, that would in general be a bad software design. Things like

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Paul Koning
> On Dec 16, 2017, at 6:14 AM, Timothe Litt wrote: > > 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

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Timothe Litt
On 16-Dec-17 07:35, Johnny Billquist wrote: > Top-posting to make it simple, while still keeping the original text. > > While it is true that device access might be done using relative > addressing, that would in general be a bad software design. Things > like device CSRs should never be accessed

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Johnny Billquist
Top-posting to make it simple, while still keeping the original text. While it is true that device access might be done using relative addressing, that would in general be a bad software design. Things like device CSRs should never be accessed as relative addresses, but should be absolute.

Re: [Simh] Custom ROMs on PDP-11 sim

2017-12-16 Thread Timothe Litt
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