20 Feb
2003
20 Feb
'03
8:01 p.m.
I would like to do a bad sector scan on a RD52 connected to a RQDX1
controller (The machine is a pdp11/73 without OS) prior to installing
BSD2.11.Is there a standalone program like zrqch0(standalone version of
zrqc from the xxdp package - only for RQDX3) that can be downloaded
directly to the pdp via vtserver and recognizes the RQDX1 , i.e. a version
of zrqb or something similar?
22 Feb
22 Feb
11:03 a.m.
New subject: PDP11 - RQDX1 standalone format utility? --> XXDP
I documented the procedure to extract a program from XXDP and put a header
on it so that you can boot it from VTserver or a UNIX disk. It has been a
long time since I did this to ZRQCH0, so I practiced on the program that I
think Christos needs (ZRQBC1) and sent it to him.
There's a lot I don't know about the a.out header, so if someone can improve
my method, let me know.
http://users.safeaccess.com/engdahl/xxdp.htm#hackXXDP
"Teach a man to fish..."
--
Jonathan Engdahl
http://users.safeaccess.com/engdahl
"The things which are seen are temporary,
but the things which are not seen are eternal." II Cor. 4:18
----- Original Message -----
From: "Christos Papachristou" <chpap(a)ics.forth.gr>
To: <cctalk(a)classiccmp.org>
Sent: Friday, February 21, 2003 4:57 AM
Subject: PDP11 - RQDX1 standalone format utility?
I would like to do a bad sector scan on a RD52
connected to a RQDX1
controller (The machine is a pdp11/73 without OS) prior to installing
BSD2.11.Is there a standalone program like zrqch0(standalone version of
zrqc from the xxdp package - only for RQDX3) that can be downloaded
directly to the pdp via vtserver and recognizes the RQDX1 , i.e. a version
of zrqb or something similar?
23 Feb
23 Feb
7:46 a.m.
New subject: [pups] Re: PDP11 - RQDX1 standalone format utility? --> XXDP
Jonathan Engdahl wrote:
I documented the procedure to extract a program from
XXDP and put a header
on it so that you can boot it from VTserver or a UNIX disk. It has been a
long time since I did this to ZRQCH0, so I practiced on the program that I
think Christos needs (ZRQBC1) and sent it to him.
There's a lot I don't know about the a.out header, so if someone can improve
my method, let me know.
http://users.safeaccess.com/engdahl/xxdp.htm#hackXXDP
There isn't very much to know about the a.out header,
and what you are doing looks OK although I would probably
have set a_text to 160000 and left a_data and a_bss as 0.
While I am not really familiar with the BSD boot code that
vtserver uses when loading a program I am almost certain that
it will use the entrypoint address in the a.out header and
not just jump to address 0. (remember it's an actual program
loader that understands a.out format, not just something that
only knows how to load a boot block and jump to it)
This is confirmed by the fact that the code you are patching
into the image at address 0 is wrong if you want it to get
you to the restart address.
In your example you have:
000020/ 000167
000022/ 145702
If this was loaded at address 0 in memory and the boot code
jumped to address 0, you would end up at 145706 *not* 145702
(of course, you might very well get lucky and still land on
an instruction boundary, but you would have skipped the first
2 words of the restart code).
If this code were really necessary (and I'm 99.99% sure that
it isn't) you would want either:
000137
145702
or:
000167
145676
12:45 p.m.
New subject: [pups] Re: PDP11 - RQDX1 standalone format utility? --> XXDP
You are right: 000137. The funny thing is, I had it right the first time.
I'll go update the web page.
On the other header fields, I agree with your idea, but for some reason, I
have this vague recollection that there was a reason for what I did with
them. It's always a bad idea to second guess something you did a year ago
and "fix" it (see the 000137 thing). It's working, so I'd best leave it
alone until it's proven to be broken. I think I remember setting it up that
way after reading through the source for some boot loader.
Hmm, yes, it was the "boot" program. VTserver squirts down a small loader
via ODT, which then loads boot.dd. Same as the boot program that the 512
byte rauboot program loads. This one:
73Boot from ra(0,0,0) at 0172150
: ra(0,0,0)unix
Boot.dd knows enough to chat with the console so you can tell it what file
you want off the virtual tape or hard drive, and it does some decoding of
the header, but it's limited. Maybe I should go read that code again.
--
Jonathan Engdahl
http://users.safeaccess.com/engdahl
"The things which are seen are temporary,
but the things which are not seen are eternal." II Cor. 4:18
----- Original Message -----
From: "Michael Davidson" <michael_davidson(a)pacbell.net>
To: "Jonathan Engdahl" <j.r.engdahl(a)adelphia.net>
Cc: <cctech(a)classiccmp.org>rg>; <pups(a)minnie.tuhs.org>
Sent: Sunday, February 23, 2003 4:40 PM
Subject: Re: [pups] Re: PDP11 - RQDX1 standalone format utility? --> XXDP
Jonathan Engdahl wrote:
>I documented the procedure to extract a program from XXDP and put a
header
>on it so that you can boot it from VTserver or a
UNIX disk. It has been a
>long time since I did this to ZRQCH0, so I practiced on the program that
I
>think Christos needs (ZRQBC1) and sent it to him.
>
>There's a lot I don't know about the a.out header, so if someone can
improve
my method, let
me know.
http://users.safeaccess.com/engdahl/xxdp.htm#hackXXDP
There isn't very much to know about the a.out header,
and what you are doing looks OK although I would probably
have set a_text to 160000 and left a_data and a_bss as 0.
While I am not really familiar with the BSD boot code that
vtserver uses when loading a program I am almost certain that
it will use the entrypoint address in the a.out header and
not just jump to address 0. (remember it's an actual program
loader that understands a.out format, not just something that
only knows how to load a boot block and jump to it)
This is confirmed by the fact that the code you are patching
into the image at address 0 is wrong if you want it to get
you to the restart address.
In your example you have:
000020/ 000167
000022/ 145702
If this was loaded at address 0 in memory and the boot code
jumped to address 0, you would end up at 145706 *not* 145702
(of course, you might very well get lucky and still land on
an instruction boundary, but you would have skipped the first
2 words of the restart code).
If this code were really necessary (and I'm 99.99% sure that
it isn't) you would want either:
000137
145702
or:
000167
145676
_______________________________________________
PUPS mailing list
PUPS(a)minnie.tuhs.org
http://minnie.tuhs.org/mailman/listinfo/pups
2:36 p.m.
New subject: [pups] Re: PDP11 - RQDX1 standalone format utility? --> XXDP
Now that I think of it,
000137
145702
is wrong too. Assuming that the program is relocatable (which in this case
it probably is not), and you simply loaded the entire file into memory, it
would be offset by the 16 byte header, so you would want to jump to 145722.
I think I will remove that patch at 20 altogether.
Did you know that the output from PDPXASM can be loaded to a barely
twitching PDP-11 via VTserver? I used PDPXASM to write scope loops for an
RX02 (DSD 4140) board I resurrected.
--
Jonathan Engdahl
http://users.safeaccess.com/engdahl
"The things which are seen are temporary,
but the things which are not seen are eternal." II Cor. 4:18
----- Original Message -----
From: "Michael Davidson" <michael_davidson(a)pacbell.net>
To: "Jonathan Engdahl" <j.r.engdahl(a)adelphia.net>
Cc: <cctech(a)classiccmp.org>rg>; <pups(a)minnie.tuhs.org>
Sent: Sunday, February 23, 2003 4:40 PM
Subject: Re: [pups] Re: PDP11 - RQDX1 standalone format utility? --> XXDP
Jonathan Engdahl wrote:
>I documented the procedure to extract a program from XXDP and put a
header
>on it so that you can boot it from VTserver or a
UNIX disk. It has been a
>long time since I did this to ZRQCH0, so I practiced on the program that
I
>think Christos needs (ZRQBC1) and sent it to him.
>
>There's a lot I don't know about the a.out header, so if someone can
improve
> >my method, let me know.
> >
> >http://users.safeaccess.com/engdahl/xxdp.htm#hackXXDP
> >
> There isn't very much to know about the a.out header,
> and what you are doing looks OK although I would probably
> have set a_text to 160000 and left a_data and a_bss as 0.
>
> While I am not really familiar with the BSD boot code that
> vtserver uses when loading a program I am almost certain that
> it will use the entrypoint address in the a.out header and
> not just jump to address 0. (remember it's an actual program
> loader that understands a.out format, not just something that
> only knows how to load a boot block and jump to it)
>
> This is confirmed by the fact that the code you are patching
> into the image at address 0 is wrong if you want it to get
> you to the restart address.
>
> In your example you have:
>
> 000020/ 000167
> 000022/ 145702
>
> If this was loaded at address 0 in memory and the boot code
> jumped to address 0, you would end up at 145706 *not* 145702
> (of course, you might very well get lucky and still land on
> an instruction boundary, but you would have skipped the first
> 2 words of the restart code).
>
> If this code were really necessary (and I'm 99.99% sure that
> it isn't) you would want either:
>
000137
145702
>
> or:
>
> 000167
> 145676
>
>
>
>
>
> _______________________________________________
> PUPS mailing list
> PUPS(a)minnie.tuhs.org
> http://minnie.tuhs.org/mailman/listinfo/pups
3:45 p.m.
New subject: QBUS SCSI card...
Why is it that the UC08 SCSI controller on ePay right now is going for a
buy-it of$799? Are QBUS SCSI controllers THAT rare? I was going to try
to find one for my MicroVAX II, but not for that kind of dosh....
tnx.
g.
4:07 p.m.
New subject: QBUS SCSI card...
Gene Buckle wrote:
Why is it that the UC08 SCSI controller on ePay right
now is going for a
buy-it of$799? Are QBUS SCSI controllers THAT rare? I was going to try
to find one for my MicroVAX II, but not for that kind of dosh....
I've seen those too. I think the seller is a little over confident. A
UC07 went for $250 just a few days ago. Qbus SCSI cards seem to top out
at about $300 to $350 from what I've seen.
Chad Fernandez
Michigan, USA
4:19 p.m.
New subject: QBUS SCSI card...
Gene Buckle wrote:
Holy cow. Never mind then. :) I'll save my money for a new radio after
my upgrade to General. :)
g.
Why is it that the UC08 SCSI controller on ePay
right now is going for a
buy-it of$799? Are QBUS SCSI controllers THAT rare? I was going to try
to find one for my MicroVAX II, but not for that kind of dosh....
I've seen those too. I think the seller is a little over confident. A
UC07 went for $250 just a few days ago. Qbus SCSI cards seem to top out
at about $300 to $350 from what I've seen.
4:05 p.m.
New subject: [pups] Re: PDP11 - RQDX1 standalone format utility? --> XXDP
In article by Jonathan Engdahl:
Did you know that the output from PDPXASM can be
loaded to a barely
twitching PDP-11 via VTserver? I used PDPXASM to write scope loops for an
RX02 (DSD 4140) board I resurrected.
I'm glad I wrote VTserver, it seems it has more uses than I thought of.
I'm out of the development loop for the new VTserver, but hopefully
it's progressing along.
Warren
7925
days inactive
7928
days old
8 comments
6 participants
participants (6)
-
chpap＠ics.forth.gr -
fernande＠internet1.net -
geneb＠deltasoft.com -
j.r.engdahl＠adelphia.net -
michael_davidson＠pacbell.net -
wkt＠minnie.tuhs.org