From df939e0afb7ba1646fabe3446c358f182f3b2a2a Mon Sep 17 00:00:00 2001 From: AJR Date: Sat, 23 Mar 2019 01:28:59 -0400 Subject: aha174x.cpp: Improve notes (nw) --- src/devices/bus/isa/aha174x.cpp | 13 ++++++++----- 1 file 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 -- cgit v1.2.3