Most microcontroller crystal circuits are both simple and reliable.
For example most parts are happy with an 18.432MHz crystal + two 22pF capacitors.

The AT89S8253 requires 0pF capacitors, and possibly a 4M resistor.
This works fine in RUN mode with voltages from 3.0V to 5.0V.

In RESET mode it seems to behave differently. It oscillates fine at 3.3V, but you do not get steady oscillation at anything over 3.5V.

So ISP programming needs to be performed at 3.3V !
The code will then RUN quite happily over the 2.7V to 5.5V working range.

The data sheet is a little ambiguous about the clock behaviour.

It appears to have an internal clock of about 4Mhz with nothing connected to XTAL1, XTAL2 pins.
An external clock signal to XTAL1 pin will work ok.
But if you have a crystal between XTAL1, XTAL2 even an external clock will not work reliably. A logic probe on XTAL2 pin will show bursts of clock cycles at roughly 15kHz 50% duty.

Does anyone have any advice and experience of this chip?

David.