Re: DC IDE adapter questions

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

abs@ wrote:

> On 7 August 2010 18:03, Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost> 
> wrote:
> >
> > Using correct parts doesn't mean it should just work.
> > Actually I had to fix several connections to make DCEXT board work.
> 
> Would you have any details on what had to be fixed to make the DCEXT board 
> run?

According to my old memo:

- it's better to have external 5V power source
  (rather than using Vcc from DC)
- Vcc and ground lines might be weak and needs more capacitors
- DC connector P9 should be NC and P12 should be GND
- IDE P1 (reset) needs some power on reset signal
- CPLD P50 (interrupt) should be connected to DC P13, not P8
- ISA IRQ lines should have pulldown
- It's better to ISA IRQ 5,9,10,11 rather than 3,4,6 etc
- ISA A14 and A15 in the patern might be swapped? (not sure)

> Also, would you have any objections to the patches being committed to
> NetBSD - obviously the audience is very limited, but having the
> patched in-tree might encourage more people to play with them.

I don't think it's worth to maintain drivers that can't be
confirmed on real hardware, i.e. no fixed specifications.
For example, ISA interrupt mappings are changed for my DCEXT mod.

It's enough to maintain private patches for private hardware,
unless it has fixed and written skematics and/or a certain
number of devices are actually manufactured, like
Neptune-X for x68k or EtherNEC and SMC_TT for atari.

---
Izumi Tsutsui