23 Apr
2001
23 Apr
'01
8:14 p.m.
Hi Zane,
I think the board he is talking about is a SCSI <==> audio CD
interface...
The original CD (not CD-ROM) interface is a three (or four) wire
affair with Left/Right, Clock, Serial data which is fed into
a DAC to produce music... The early CD-ROM drives took these
signals, recognized the sector header (00-FF-FF-FF-FF-00 IIRC)
and decoded the data. Presumably, some extra signals were added
to control seeking, etc...
I've got one of these boards, and I suspect the parts removed
were: 80C31, 27C256, and NCR 5380 (only parts socketted).
The drive is completely useless without these chips.
clint
On Mon, 23 Apr 2001 healyzh(a)aracnet.com wrote:
No kidding, they'd have been interesting if not
for that, since I'm assuming
they're M7552 Q-Bus boards (which aren't really SCSI boards). :^(
Zane
How is anybody going to use the boards if you
have removed chips?
Chad Fernandez
Michigan, USA
Eric Dittman wrote:
Also, the SCSI adapters are only for the
RRD40 drives and I've removed the three
ICs that are useful to me from each board.