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Adventure on PDP-11/03

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jmdhuse

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Hello All,

I've built a small system consisting of:

M7264-YC PDP-11/03 CPU with no on-board DRAM
M8044-DH 32KW DRAM (only 28KW is exposed to the system)
M8043 Four-port SLU module (DLV11-J)

I have it running RT-11SB V05.07 by booting from the TU58FS emulator. I would like to run Adventure, as I was given to understand that it was commonly run on an equivalent configuration. However, when I try to run it, I get this error: "?Err 30 No room for buffers". The error message makes me think that it wants more memory than the system has.

Can someone shed light on this? Perhaps I am wrong in thinking this PDP-11/03 configuration is sufficient. Is there another version of Adventure that fits in this memory space?

Thanks, Jon.
 
Sure sounds like it wants more memory. I know that the pdp-8 version took the full 32k to run it. I was not able to find any info on an RT-11 version besides the info that there was one and it seems to have been in Fortran.
 
I have been running Adventure on a 28 kW machine. But it had RX02 and an older version of RT-11. You might try to boot RT11 v4 instead.
 
That seems to be the standard /03 configuration. I would ask which version of Adventure you are trying but I don't remember and can't find which one is most compact.

The FORTRAN manual does have a primer on how to free up the little bit of memory needed for buffers. Perhaps the setup is allocating a bit too much memory for functions not required.

NO ROOM FOR BUFFERS

There was not enough free memory left
to set up required I/O buffers.


(RT-11 only)

Reduce the number of logical units that are open
simultaneously at the time of the error. If using
double buffering or if another file is currently
open, use single buffering. Make more memory
available by unloading unnecessary handlers,
unloading the foreground job, using the single-job
Monitor, or SET USR SWAP, if possible.
Click to expand...
 
It will run on RT-11 V5 in 28KW, but you may need to unload some of the unused device drivers - especially the SL driver, or use an earlier version of V5...

Failing that, it could need a smaller sysgen - i.e. less options enabled, but I think you can get it working with just less drivers loaded

I am going to be setting this up sometime soon - so check back with me if you're still stuck!

Robin
 
Yes, you need to think about how to make a minimal RT-11 system to maximise the memory available to Adventure.

Dave
 
So here's what I did... Removed a couple of drivers and configured the memory to only reserve the top 2KW for I/O, instead of the normal 4KW... That freed up enough and now it runs fine. Thanks for the suggestion! Cheers, Jon.
 
Yep, going to a 2kw IO space makes a big difference. I also had Dungeon compiled up for RT11 on a PDT11/150, so there are a bunch of good games (space invaders is great on a VT52 as is DECMan)
 
As I think about this, there will be a restriction on tje type of boot ROM that can be used with the reduced I/O space... Boot ROM code written for the BDV module should work fine, as the ROM window is located in that upper 2KW of I/O space. However, the MXV-style boot ROM codes make use of two windows, one in the upper 2KW and one in the lower 2KW, so I'm guessing they are a no-go for this kind of system configuration.

I'll verify this when I get a chance.
 
jmdhuse said:
As I think about this, there will be a restriction on tje type of boot ROM that can be used with the reduced I/O space... Boot ROM code written for the BDV module should work fine, as the ROM window is located in that upper 2KW of I/O space. However, the MXV-style boot ROM codes make use of two windows, one in the upper 2KW and one in the lower 2KW, so I'm guessing they are a no-go for this kind of system configuration.

I'll verify this when I get a chance.
Click to expand...
+! for this, so you lose the 16xxxx address space for the MXV11-B and default address space for DZV/DHV11 boards and others

Adventure runs with the full I/O address space and just minimal drivers loaded, usually - you could have a command file unload what you don't need for ADVENT and still have them enabled by default
 
Last edited:
Radix said:
+! for this, so you lose the 16xxxx address space for the MXV11-B and default address space for DZV/DHV11 boards and others

Adventure runs with the full I/O address space and just minimal drivers loaded, usually - you could have a command file unload what you don't need for ADVENT and still have them enabled by default
Click to expand...
So maybe unload everything but the DD and TT drivers...
 
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