17 Apr
2000
17 Apr
'00
9:23 a.m.
> Recently, as part of my effort on an S-100
"hard-card" using a 2-1/2
> inch ide drive, I've been revisiting the 1994 standard for the ATA
> interface. There's a not-too-detailed mention of an 8-bit mode which is
> set up using a bit in register. This feature was apparently obsoleted
> as of 1996's standard.
It's actually not that hard to use a normal 16 bit
IDE drive in an 8 bit
system (like an S100 card). You need a few buffers/latches to convert
between 8 and 16 bits on read/write, that's about it.
Actually, although it pains me to say this, IDE drives
are so cheap per
megabyte now that you could probably get away with wasting every other
byte... Just use a 3-state buffer to always write the top 8 data lines as
0 (or FF or...) and ignore them on read. After all, people give away 1Gb
IDE drives these days (or so I've heard), and 500M of storage (i.e.
wasting every other byte) is massive for S100 systems.
Quite an inriguing idea. You also will get 256 Byte records ...
a more common size back then. Well, what about commands etc. pp ?
Gruss
H.
--
VCF Europa am 29./30. April 2000 in Muenchen
http://www.vintage.org/vcfe
http://www.homecomputer.de/vcfe