9 Dec
2006
9 Dec
'06
6:02 a.m.
On Friday 08 December 2006 12:04, you wrote:
On 8 Dec 2006 at 9:06, joseph c lang wrote:
Actually My first draft was a 555. By the time all the requirements were met,
the component count had gotten out of hand. 7420,555,7438,handfull
of descretes... a single 20 pin package a crystal and a transistor didn't
seem like overkill.
And it would handle the creeping feature bloat My projects suffer from ;^)
joe
I have a pair of teac fd55gfr (5.25 DSDD) drives
running on a Monolithic
systems Z80 multibus board. I built a small board to handle the connector
difference. I used an AVR to generate the missing motor on signal.
It looks at the drive select signals and asserts motor on if any drive is
selected. It deasserts motor on after 15 seconds of no drive selected.
I guess I AM showing my age. My first impulse would have been to use
a 555--and the same for synthesizing a READY* signal if the drive
had no jumper to provide one.
Although using an AVR or PIC is also a great idea--just never thought
of using an MCU for such a simple job. Geezer's disease, I guess.
Cheers,
Chuck