🚀 go-pugleaf

Howdy folks,

I've finally gone out and bought another 4 Meg for my pc532 to bring it
up to 8 Meg.  I got home, plugged it in and powered it up, and fired up
Minix.  I did a ps, and it tells me there's only 760 odd free pages,
not the 1700 odd I'd expected.  Back to the monitor, and I did a
	dump 3ffff0 20
and what it returned looks something like this:

03ffff0 | 00 00 00 00   00 00 00 00  00 00 00 00  00 00 00 00 | ................
0400000 | 00 00 00 ff   00 00 00 ff  00 00 00 ff  00 00 00 ff | ................

So, obviously, there's something amiss with one bank of memory.  I've
tried replacing the SIMMs in a different order, but that didn't fix the
problem.  I've also checked the board closely for dry joints and
resoldered any that looked suspect.

Basicly, what I'm after is some pointers as to where exactly I should
be looking for the problem.  I've tried to isolate the problem looking
at the circuit diagram, but it was just a little too much for me, and
short of redoing all the solder joints, I'm at a loss at what to do.

I don't have a CRO available, just my iron and trusty DVM.  I'm also
running the autoboot EPROM, if that makes a difference (but I don't see
how).

Thanks in advance,
  Simon.

ps: While I'm here, does anyone have a solution to the abyssimally slow
    file system?  I work out that I'm getting roughly 50k/sec through
    the MINIX fs, but the monitor seems to get almost a meg/sec.  I
    realise that there's going to be some OS overhead, but...
--
Simon Burge, on an almost properly working pc532!
snark@thistledown.img.com.au