View Single Post
Old 19th Oct 2018, 1:11 pm   #51
Station X
Moderator
 
Station X's Avatar
 
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
Default Re: 486 PC. Keyboard problem.

I said I'd post an update as to how the problem was fixed, so here it is. Please feel free to "ESCAPE" at any time if it gets boring.

My initial aim was to get the built in PC working. It has no hard disk so I produced an MS-DOS start up disk using a Windows XP PC. In order to get the built in PC to produce a DOS prompt I had to replace the CMOS battery, reconfigure the BIOS to recognise the floppy disk drive, connect a QWERTY keyboard using a PC/XT to PS2 adaptor lead and replace the floppy disk drive. Having done all this the built in PC reliably booted to a DOS prompt every time.

Next I wanted to get the PC talking to the control box which in turn talks to the machine. The built in PC to control box link is RS232. The machine is a Denford Mirac. This is a training lathe often found in schools and colleges. Denford support their legacy machines on an informal basis through a forum. Machine specific software disks aren't available, but the files can be downloaded from the Denford website.

I downloaded the files and copied them to a disk. The disk was then put into the previously booted PC, which was showing a DOS prompt. I typed in the name of the .exe file and the software ran. Unfortunately it aborted at an early stage with no specific info about the error. I eventually discovered that I needed to copy the com port driver files to the disk. These weren't included with the downloaded files.

I ran the software again from the DOS prompt. The com port drivers were installed, but the software aborted again with the same error message.

I decided to try a different approach ie loading the application files and drivers to an MS-DOS start up disc rather than running the application from a DOS prompt. This would have been how the machine was originally used. I created an MS-DOS start up disk using my Windows XP PC. Then I deleted all the files from it apart from IO.SYS, MSDOS.SYS and COMAND.COM. I understand this is the minimum set of files needed and thought it would more closely resemble a disk from the DOS era rather than the Windows era. Next I copied the application files to the disk and created an AUTOEXEC.BAT file containing just the name of the .exe file.

This worked correctly. After the com port drivers were loaded the application software communicated with the control box to check that the correct firmware was present. I was then able to talk to the machine via its built in keyboard. It all works correctly apart from the tool changing turret. I'm sure I can fix that, but these forums are not the place to discuss machine tools.

So I've fixed the problem and everything works, but I've no idea why. I'm afraid life is too short for me to investigate further.
__________________
Graham. Forum Moderator

Reach for your meter before you reach for your soldering iron.
Station X is online now