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-rw-r--r--src/devices/bus/isa/aha174x.cpp13
1 files changed, 8 insertions, 5 deletions
diff --git a/src/devices/bus/isa/aha174x.cpp b/src/devices/bus/isa/aha174x.cpp
index 9453f6a1856..b82888ca73f 100644
--- a/src/devices/bus/isa/aha174x.cpp
+++ b/src/devices/bus/isa/aha174x.cpp
@@ -7,11 +7,14 @@
These are actually EISA cards, though they also have a compatibility
mode that provides an interface like the older ISA AHA-154X series.
- The HPC microcode is copied to and then executed out of RAM, allowing
- it to be reprogrammed by the host.
-
- The AHA-1740 and AHA-1740A have different board layouts and require
- different microcode, though they share the following ICs:
+ On the AHA-1740 and AHA-1744, the HPC microcode is stored in an EEPROM
+ (of unknown type), allowing it to be reprogrammed by the host. This is
+ not possible on the AHA-1740A and AHA-1744A, which use a conventional
+ 27C256 EPROM for the microcode. In both cases the HPC copies the code
+ to and then executes it out of RAM.
+
+ Though the AHA-1740 and AHA-1740A have different board layouts, they
+ share the following ICs:
AIC-565 Bus Auxiliary Interface Chip
AIC-575 EISA Configuration Chip