fayne@tellab5.TELLABS.COM (Jeffrey Fayne) (02/07/90)
I seriously considering purchasing NuMega's 386 debugger, however
I have a few questions for anyone who has used this program:
1) Is it as powerful as the ads make it out to be ?
I'm particularly interested in it's 'back trace'
capability (will it allow you to step backwards
thru your code once a breakpoint is hit or will
it just show you how you got to the breakpoint?).
2) I understand the program is codeview compatable,
therefore it should be TurboDebugger compatible
as well. True or false ?
3) Talking to a sales type, he claims that there is
a beta version available that supports Plink86
symbol tables (however I believe he stated that just
the root is supported or is the beta version for the
overlays?) Is anyone using this beta version and if so
problems? As an alternative, I understand that SoftIce
is compatable with .RTLINK/PLUS, any recommendations as
far as switching linkers? I'm very happy with PLINK, but
if I find SoftIce 'invaluable', I may switch.
4) Ideally, I would eventually like to run SoftIce under
VM/386 (multitasker), is this possible? If not why not
and will it run under any other multitasker?
Any observations would be greatly appreciated.
Jeff
--
_____________________________________________________________________________
F-14 | _ | | Jeffrey M. Fayne
Tomcat | /^ ^\ | | Tellabs, Inc.
____________|_( . )_|____________ | Lisle, IL (708)-512-7726
--*/--|_| (___) |_|--\*-- | fayne@tellab5.UUCP
* O O * fjs | Standard Disclaimer Applies
_____________________________________________________________________________geoff@hinode.East.Sun.COM (Geoff Arnold @ Sun BOS - R.H. coast near the top) (02/09/90)
Quoth fayne@tellab5.TELLABS.COM (Jeffrey Fayne) (in <2078@tellab5.TELLABS.COM>): #I seriously considering purchasing NuMega's 386 debugger, however #I have a few questions for anyone who has used this program: # # 1) Is it as powerful as the ads make it out to be ? # I'm particularly interested in it's 'back trace' # capability (will it allow you to step backwards # thru your code once a breakpoint is hit or will # it just show you how you got to the breakpoint?). I've been developing PC-NFS since 1985, and over that time I've come to rely on three debugging tools: The Network General Sniffer, IBM's PC-Watch, and SoftIce. Each is, in its own way, invaluable. The back trace facility stores every instruction within the trace range in the circular buffer. Whenever SoftIce gets control (via breakpoint, exception, or hot-key) you can browse this buffer. Most of the work I do is low-level assembler stuff (redirector, network driver, etc.), and the most painful bugs are always blown stacks, segregs, etc. which usually result in a return to a random address. Since Intel (in their infinite wisdom) failed to make 00H the "halt" instruction (didn't we learn ANYTHING in the 60s?), the back trace is the best way of nailing things. It even works across reboots, so that I can trace through all the DOS and driver startup code. #[Questiona about TurboDebugger and PLINK) No data. I use Microsoft Link, don't use overlays. # 4) Ideally, I would eventually like to run SoftIce under # VM/386 (multitasker), is this possible? If not why not # and will it run under any other multitasker? Almost certainly not. SoftIce takes over the 386 and runs your DOS session in a virtual 8086, which will conflict with any other software which wants to act as a hypervisor. For example, you can't run Windows/386 with SoftIce. (As far as I know, no microprocessor has the necessary hooks to run a fully recursive VM architecture - i.e. running a 386 virtual machine under a hypervisor. In this respect we still can't emulate VM/370. One day, maybe.) Geoff Arnold, PC-NFS architect, Sun Microsystems. (geoff@East.Sun.COM) ----------- News software that enforces a four-line .signature limit is responsible for the fact that these postings just go on and on and on and seem to end in mid-
pipkins@qmsseq.imagen.com (Jeff Pipkins) (02/10/90)
In article <2078@tellab5.TELLABS.COM> fayne@tellab5.TELLABS.COM (Jeffrey Fayne) writes: >I seriously considering purchasing NuMega's 386 debugger, however >I have a few questions for anyone who has used this program: > > 1) Is it as powerful as the ads make it out to be ? > I'm particularly interested in it's 'back trace' > capability Yes on both counts. It's not just a back trace, it gives you back trace simulation, meaning you can see what the registers were at a given instruction. The back trace makes the program run slower, which may preclude its use with some real-time systems. > 2) I understand the program is codeview compatable, > therefore it should be TurboDebugger compatible > as well. True or false ? You can probably use it with just about any debugger that is out there. I prefer to use it standalone. It can set breakpoints that ordinary debuggers can't, like break if code in this area writes to memory in that area. You can tell it what you want it to do when it gets one of these breakpoints. If you tell it to do an int 3, which most debuggers use for breakpoints, you can probably get it to work with just about anything. But you can do symbolic debugging without using anything except Soft-Ice. > 3) Talking to a sales type, he claims > [salesman's claims deleted @;-) ] > any recommendations as > far as switching linkers? I'm very happy with PLINK, but > if I find SoftIce 'invaluable', I may switch. I've never had any reason to switch to a linker that I had to pay extra for. But whatever reason you have, I don't see how it could convince you to live without Soft-Ice. I won't. > 4) Ideally, I would eventually like to run SoftIce under > VM/386 (multitasker), is this possible? If not why not > and will it run under any other multitasker? I seriously doubt this is possible. With any other multitasker, I'm quite sure of it. Soft-Ice gets its power from using the privileged modes of the 386, taking advantage of all kinds of processor exceptions caused by certain kinds of instructions and the memory protection scheme. This would conflict with any other program (i.e. OS) that does the same. Theoretically, VM is an operating system that can run other operating systems by providing them with the illusion of a virtual machine. As implemented on the old IBM mainframes, any OS that could run on the bare machine could be fooled into running under VM. As to whether this principle has been successfully transferred to the VM/386 implementation, I don't know, but I'd like to hear from anyone who knows for sure. I went to an ACM convention once where a couple of guys gave a talk about why it was impossible to do on the 386, and this may be one of the main reasons for the 486. But hell, I've already told you more than I know. @;-) I'm not associated with Nu-Mega. I think their name is silly, but I wouldn't be without Soft-Ice. I have used it in debugging a multitasking kernel (real mode only) and I swear by it. But standard disclaimers still apply...
harper@convex.com (David Harper) (02/13/90)
In article <2078@tellab5.TELLABS.COM> fayne@tellab5.TELLABS.COM (Jeffrey Fayne) writes: >I seriously considering purchasing NuMega's 386 debugger, however >I have a few questions for anyone who has used this program: I have been following this discussion for several days now and find it quite interesting. Unfortunately, one thing that has not been mentioned is where the program is available or how to get ahold of NuMega. I looked all through the lastest version of PC Magazine for an ad either from NuMega or someone who might distribute it and came up empty. Various other catalogs from software distributers I have used in the past also didn't help. Anybody have any suggestions? Dave Harper - Convex Computer Corp. E-mail address: 3000 Waterview Pky. Richardson, TX 75081 harper@convex.COM (214) 497-4525 (W) (214) 727-4206 (H)
malloy@nprdc.arpa (Sean Malloy) (02/15/90)
In article <-1773786500@convex.convex.com> harper@convex.com (David Harper) writes: |In article <2078@tellab5.TELLABS.COM> fayne@tellab5.TELLABS.COM (Jeffrey Fayne) writes: |>I seriously considering purchasing NuMega's 386 debugger, however |>I have a few questions for anyone who has used this program: |I have been following this discussion for several days now and find it quite |interesting. Unfortunately, one thing that has not been mentioned is where |the program is available or how to get ahold of NuMega. I looked all through |the lastest version of PC Magazine for an ad either from NuMega or someone |who might distribute it and came up empty. Various other catalogs from |software distributers I have used in the past also didn't help. Anybody |have any suggestions? The latest issue of Micro Cornucopia has a full-page ad from Nu-Mega on page 2; their address is listed as: Nu-Mega Technologies P.O. Box 7607 Nashua, NH 03060-7607 The phone number listed is (603)888-2386. Sean Malloy | Navy Personnel Research & Development Center | "The morning was death San Diego, CA 92152-6800 | with birdsong." malloy@nprdc.navy.mil | -- _The Wizardry Compiled_