The GlueX experiment at Jefferson Lab will use a 9 GeV
high-rate ($10^7 -10^8/s$) photon beam,
incident on a liquid hydrogen target,
to search for hybrid-meson production 
in the mass range of 1.5-2.5 GeV/$c^2$.
Abundant photon production from neutral meson decays 
is expected in the decay chains of hybrid mesons, 
which will result in several photons in the forward region.
The forward electromagnetic calorimeter (FCAL) of the GlueX detector
is designed to reconstruct final state photons using an array of 
2800 lead-glass blocks. The FCAL will employ 
flash analog-to-digital converter (FADC) technology 
to measure both deposited energy and photon arrival time
using pulses from FEU-84-3 photomultiplier tubes.
A real-time sum of the total calorimeter energy will be
used as an input to the trigger. 
Timing information from individual crystals will be used to
suppress the expected high-level of electromagnetic
background from the photon beam and forward-going charged particles.
We present the performance characteristics of the calorimeter readout 
based on simulation and data taken with a prototype 
12-bit, 250 MHz flash ADC.