Well looks like I have been living in the past ...
I have been using v3.9 SIMH from the SIMH website (the 'legacy' version) and
have now gone an upgraded to the github v4.0 version. This one it appears has
supported the serial virtual TU58 device since mid 2015 (at least by comment dates).
I have tried it, and it successfully boots my XXDP TU58 images, as one should
expect.
However, I tried mounting a larger than 256KB physical TU58 image on the virtual
TU58 (as one can do with a real TU58) but it does not appear to work as I
expect. I should be able to mount a 10MB RL02 XXDP image on a TU58 and then do
read-only accesses to the full image. The real TU58 protocol supports up to 32MB
devices (512 blocks of 512 bytes) but it seems that the SIMH TU58 only supports
a physical TU58 tape image of 256KB. I'll have to do some more experiments and
read some code to see what is going on.
If this restriction is in place it does rather significantly limit the utility
of the TU58 virtual serial device, in not allowing one to build an (up to) 32MB
disk image under SIMH, and then move it to a real TU58. Limiting simh to only
256KB sized images is being true to the physical limitation of TU58 cartridges,
but not true to the actual capability of the TU58 serial line protocol.
Don
On 3/11/2016 11:19 AM, Richard Cini wrote:
I had a little time after lunch to try the below procedure and using the beta
version of SIMH I am able to create a tape image that's bootable by SIMH
without the below error.
I copied the following to the image, which I will try with TU58em when I get
home tonight:
DD, TT, rt11sj, DU, SL, LD, pip, dir, swap, dup, and starts.com.
The size of the image is 504 blocks (264 free).
Rich
Sent from my iPhone
On Mar 11, 2016, at 1:26 PM, Mattis Lind <mattisl...@gmail.com> wrote:
SIMH has never directly supported mounting/attaching virtual TU58 devices.
Altho the required serial interface
is emulated (ie, a plain DL11 at 776500/300) the TU58 drive behind the
serial interface has never been emulated.
I just tested the latest SimH from github and it is indeed possible to
enable tdc and attach an image file to the tdc0 device. I then booted into
RT11 from a DU-device and did INIT DD0: no problem.
Then I made a bootable DD image. I did even do a BOOT DD0: which gave me a
RT11-prompt. But booting from SimH failed on me. I am not sure why.
MattisMacBook:BIN mattis$ ./pdp11
PDP-11 simulator V4.0-0 Beta git commit id: 1b6f28a7
sim> set tdc enable
sim> attach tdc0 rt11-dd.dsk
TDC: creating new file
TDC: buffering file in memory
sim> attach rq0 rt11v53-games.dsk
sim> b rq0
RT-11SJ V05.03
.init dd0:
DD0:/Initialize; Are you sure? Y
.copy dd.sys dd0:
Files copied:
DK:DD.SYS to DD0:DD.SYS
**** Copying some files *****
.copy rt11sj.sys dd0:
Files copied:
DK:RT11SJ.SYS to DD0:RT11SJ.SYS
.copy/boot rt11sj.sys dd0:
.boot dd0:
RT-11SJ V05.03
.dir
DD .SYS 5P 20-Dec-85 TT .SYS 2P 20-Dec-85
SWAP .SYS 27P 20-Dec-85 STARTS.COM 1P 20-Dec-85
DIR .SAV 19P 20-Dec-85 DUP .SAV 47P 20-Dec-85
DU .SYS 8P 20-Dec-85 RT11SJ.SYS 79P 20-Dec-85
8 Files, 188 Blocks
316 Free blocks
.boot du0:
RT-11SJ V05.03
.
Simulation stopped, PC: 146414 (BCC 146446)
sim> exit
Goodbye
TDC: writing buffer to file
PDP-11 simulator V4.0-0 Beta git commit id: 1b6f28a7
sim> set tdc enable
sim> attach tdc0 rt11-dd.dsk
TDC: buffering file in memory
sim> b tdc0
Trap stack push abort, PC: 000000 (WAIT)
sim>
I have no idea why SimH is not able to boot from the simulated DD0: device.
The steps to make a bootable dd0: was exactly the same steps as to make a
bootable RK0: which works just fine.
Ersatz-11 on the other hand works fine with the same image:
E11>assign tt1: dda:
E11>mount dda0: rt11v53_dd.dsk
E11>b tt1:
RT-11SJ V05.03
.dir
TT .SYS 2P 20-Dec-85 DD .SYS 5P 20-Dec-85
RT11SJ.SYS 79P 20-Dec-85 SWAP .SYS 27P 20-Dec-85
STARTS.COM 1P 20-Dec-85 DIR .SAV 19P 20-Dec-85
RESORC.SAV 25P 20-Dec-85
7 Files, 158 Blocks
346 Free blocks
.
This is the image that boots in Ersatz-11 but not in SimH:
https://dl.dropboxusercontent.com/u/96935524/rt11v53_dd.dsk.gz
Since it boots on Ersatz-11 when set to 11/03 CPU it should work on the
real hardware.
BTW. It not so that the LTC interrupt is enabled in your system? I have had
problem with that one. In certain cases it need to be disabled. If I
remember correctly I had problems booting RT11 from MSCP devices with LTC
enabled.
/Mattis
Don
