24 Apr
2007
24 Apr
'07
6:16 a.m.
On 24 Apr 2007 at 5:16, Ensor wrote:
Having reverse engineered the ROMs in a couple of old
6502 based Atari video
games a few years back, it's not something I'd consider doing again in a
hurry (and I had circuit diagrams to work from).
I still routinely disassemble drivers and ROMs--and the tools have
gotten hugely better. A good diassembler such as IDA is wonderful.
The original IDE drives used 8-bit transfers (I had
one in my first XT),
even to this day there is still be a signal on the IDE interface to force
the use of 8-bit mode.
It's safe to say that there hasn't been an IDE drive manufactured
within the last 10 years that supports 8 bit data transfer mode.
Even many of those that claim to support it don't (probably just
vestigal "cut and paste" text). I once went through my stack of
320MB and up 3.5" IDE drives and couldn't find a single one that
actually supported 8 bit PIO Mostly, IOCS16- is ignored on most
drives. There was a considerable amount of debate in X3T10 when ATA-
2 was being hammered out as to whether IOCS16- should even be
included in the list of signals (it was removed when X3T10 defined
ATA-3). It was reinstated in ATA-5 on request from the CF group.
On CF, IOCS16- is honored--but it's not on any IDE hard drive you're
going to buy today.
Cheers,
Chuck