2 Feb
2006
2 Feb
'06
11:18 a.m.
It's no news that cd-roms could operate in older
machines. I remember a friend with a Tandy 1000
something years ago who had one hooked up (can't
remember if it was internal or external though). And
he could listen to music while he was doing
*presumably* something useful with the machine.
Most older CD-ROM drives had built-in DACs and thus an audio output. You
could use that to play a music CD without using any of the host
computer's CPU cycles at all (the external Philips I have has
play/stop/skip track controls on the front, it can be used as a simple
audio CD player without connecting it to a computer).
There was often an audio connector that you linked to your soundcard,
but that just fed into the mixer stage of the soundcard. Again no host
CPU cyclers were needed.
It would be nice to obtain a schematic of one of the
more primitive IDE cards *whistles*. And wouldn't
I did trace out the schematics of the one in this machine. To be honest,
it was totally trivial. A few buffers and a PAL. I would thoink you could
design one by reading the IDE spec/
artwork be nice too ;). Would an 8-bit card take the
place of a 16-bit card in an AT? Presumably yes,
albeit slower I guess. The Acculogic sIDE/16 or
Most IDE drives expect a 16 bit data bus, at least for the data register.
The 16 data lines from the drive are buffered and fed to the 16 data
lines on the ISA slot.
-tony