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author AJR <ajrhacker@users.noreply.github.com>2019-03-23 01:28:59 -0400
committer AJR <ajrhacker@users.noreply.github.com>2019-03-23 01:28:59 -0400
commitdf939e0afb7ba1646fabe3446c358f182f3b2a2a (patch)
treef5c854e8b84593c25144c4dcf5aab4305752e552
parent5f7021ed8c0fc37ef3f7bee62cd1c9b3e90a52c6 (diff)
aha174x.cpp: Improve notes (nw)
-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