🚀 go-pugleaf

<joachim.maes@dma.be.NOSPAM> wrote:
>I have to recover the files on a harddisk in an old XT with blownup EGA
>Monitor.
>His screen can not be repaired and  I don't have a spare EGA Monitor.
>The PC just gives the annoying beep (no monitor present) and stops booting.
>This makes it impossible to recover the files via laplink.
>(Disconnecting the hard disk is not possible, 'coz it has a giant controller
>board that can't handle todays clockfrequencies.)

What makes you think the controller can't work in a current PC?
ISA is still ISA.  There weren't many controller boards that
couldn't handle 8 Mhz ISA (vs. 5.77 Mhz).  You would have to
primary the hard disk controller in the PC (due to IRQ usage).

>My idea was to fool the necessary lines on the EGA Connector, so that the
>booting proces continues and I can recover the files of the old PC; but I
>can't find any sources describing which pins the motherboard checks for
>presence of a monitor. I was not able to verify the state of the
>videoadapter.

The EGA port has no way to detect the presence of a monitor.
If the PC is beeping, it's not because a monitor is not connected.

>The other alternative is to build an EGA-VGA Convertor (EGA Connector -> Vga
>Connector)

This is not possible.  They run at different frequencies.

>I'm not sure this is a healthy thing to do for my VGA monitor....

Other possible solutions:

1.  Go to a thrift store and get an old PC and monitor.
    Swap out components.
2.  Find an XT-compatible VGA card.
3.  Find a more recent HD controller of the type you need.
    Is it ST-506/MFM, ST-506/RLL, ESDI, or something else?