Nokia

Thanks for the info. I need to run LTspice and dos programs in the same vm. My dos programs edit the ASC files and load the desired one into LTspice. They need direct access to the files and the LTspice executable. The only way I know how to do this is by running XP and switching to DOS mode.

One of the problems doing this is 100% cpu utilization. I use TameDos which works well. The utilization drops to ~1% when dos is not doing anything.

I found version 4.5 works best in my system. I paid for a license but the registration does not work for v4.5. Without registration, the program gives a nag screen if you stay in a dos program for half an hour or so. This is a minor inconvenience. The author does not respond to my emails requesting help.

One of the problems with running XP is to do a complete backup of all data and system files. I run XP in Virtualbox in Ubuntu 10.04. This allows saving a complete backup in a matter of seconds so it is very easy to keep the backups updated. You can also copy the vdi file to another computer and have a byte-identical copy running on a completely different motherboard, hard disk and monitor with no changes required to XP. This is normally impossible to do.

However, there are very severe problems with the Microsoft/Intel UEFI bios which renders all the motherboards I have purchased recently completely unusable.

Phil Hobbs runs a Supermicro mb which does not use UEFI. I have one on order and will find out in a couple of weeks if it will work in my application.

Thanks,

JK

USB to parallel converters are cheap. However, it is probably best to simply move over to USB and use any of the small micros to interface to the hardware. If nothing else, the data rate on USB is far greater than on a parallel cable, so you can upgrade the design to give better performance.

A flat ribbon cable is a real pain to handle on a workbench. You have to have a way to check each bit on the cable to make sure they are all good. USB is much smaller and easier to use on the workbench, and you don't have a zillion bits to constantly monitor.

JK

But most of them don't work. There's plenty of USB to _printer_ adaptors, but if you don't want to connect a printer things get more difficult.

hmm, it seems the Lucent USS720 chip can do it. however it is 1000 times slower than PCI when in bit-bang mode

However, it is probably best to

wine is not virtualisation, dosemu is kind-of

file access is possible, (dosemu hs couple of different modes, and I'm fairly sure one of them makes the linux files available)

I'm assuming you mean they need to be able to launch ltspice. I think there's a way you could make a fake "swcad.exe" and have that launch wine and ltspice when run in dosemu

In my experieince ubuntu 10.04 is worse than UEFI

I do it with symlinks. My home directory appears in my dosemu as C:\UNIX.

God, how I hate drive letters, and backslashes. Not to mention 8:3 munged filenames :-)

Dosemu isn't a VM, it's an environment that allows running 16-bit, real mode DOS applications within the 32-bit linux environment. All dosemu files are part of the native (EXT, or Reiserfs), filesystem. There's no FAT filesystem, nor is the CPU ever operating in real mode.

You can access your linux files from dosemu simply by making a symlink to your home directory, within your dosemu hierarchy. I'm fairly sure you can launch LTspice in wine, from dosemu, with a DOS-type batch file, I've not tried it (yet).

I think I've already covered that. Using freedos in dosemu, it just won't happen. The underlying linux OS still controls time slicing.

If your DOS apps are of your own making, I'd be tempted to rework them as octave code. Octave can talk to Berkeley Spice, which, admittedly, doesn't have all the LTspice bells and whistles, but might do what you want.

Thanks for all the good information. For me, XP in a vm is the way to go. I can use all the windows programs without having to run wine. I can back up the entire vdi file in seconds so it is easy to keep updated backups. I can copy the vdi to another computer and have a byte-identical copy running on a completely different computer with no change.

More important, I can have several independent vdi's for different purposes. One example is for online banking. All the logon info is encrypted in Sticky password manager so there is little risk of id theft. None of the logon info is stored anywhere else so there is little risk of having it stolen.

It only goes to my financial sites and is not used for general browsing so there is little risk of id theft. It has none of the vulnerable programs such as Flash, PDF, and so on. It has no email so it cannot be infected by phishing attempts. It has no LAN capability so it cannot be infected from other vdi files on a network. It has no USB interface so it cannot be infected by inserting a usbstick. The vdi file is only used for banking and is turned off when done. In other words, the banking vdi is deliberately and completely crippled for anything other than the occasional banking use.

Many of the worst banking malware, such as Zeus, turn themselves off as soon as they detect they are running in virtual mode. This is to protect the authors from honeypots.

I can monitor the condition of all the system files in the different vdi's so I know if something has been added or changed. This takes only seconds so it is easy and convenient to do. I do not have to rely on multiple antivirus programs that cannot guarantee there is no infection.

It is backed up with various rootkit detectors so if a malware tries hiding, it will be detected. If it doesn't try to hide, it will be detected with the first method. If one of the other vdi files happens to get infected with a keylogger, it won't do any good. None of the keystrokes from one vdi are available to any of the others.

The host runs on Linux and is rarely used for browsing. So there is little risk of an infection that might threaten the banking vdi. If there was an infection, it could not cross the boundary between Linux and the Windows operating system.

I believe this is the most effective way of combining the best features of Linux and Windows, and it gives the most secure method of using online banking that is possible to achieve.

JK