ranjit@grad1.cis.upenn.edu (Ranjit Bhatnagar) (08/27/89)
Some of you may remember my adventures with an Amiga 1000 (rev 6)
and a Ronin Hurricane (020 and 881 at 20 MHz) of a few months ago.
With the Hurricane installed and the PALs grounded, the system
wouldn't boot. (Helpful Hint: if someone offers you "An Amiga 1000
and an Accelerator Board," make sure he means "An Amiga 1000 with
a Compatible Accellerator Board Installed and Tested" before you
sign anything!)
Anyway, I got the CLtd PAL upgrade a few days ago, and jammed it
into the machine. Then I plugged in the Accelerator, and - VOILA.
The machine now boots just fine. And it does a lot of things real
fast (and some things slower, of course, since I have no 32-bit
memory). BUT - it always crashes sooner or later, and, strangely
enough, the crashes depend on the software I'm using. The only
other foreign hardware installed is a Comspec 2-meg autoconfig
memory card. Note that the machine still works reliably with the
68000 installed; I go 2 or 3 weeks without rebooting.
ashell and the ARP 1.3 commands - never crash
vt100 r2.8 - always crashes within 5 minutes, on a keypress
or menu-button press.
vlt - ditto.
DPaint II - eventually crashes.
DigiPaint 1 - never crashes.
SimCity - eventually crashes when a mouse button is pressed.
Music Mouse - doesn't crash.
All the Killer Demos from the 0th contest - never crash.
(But Nemesis's graphics lose synch with the music.)
Sculpt-3D - doesn't crash.
When a crash comes, it is either the classic 'hang' or a GURU
with a CPU trap. The trap is 4 (illegal instruction), A (A trap),
or B (B trap), and occurs in the 200000 range (expansion memory).
This is weird, since if the software actually contained any illegal
instructions or A/B traps, it would crash a 68000 amiga too. But
if there is a hardware problem causing the crashes, why does it
depend on what software I use??
More weirdness: the crashes nearly always occur when I hit a key
or press a mouse button (especially the menu button). This suggests
a problem with Intuition or the input.device. Yet if this is the case,
why don't mouse moves, disk inserts and ejects, and so on, ever cause
crashes?
Intuition and the input.device reside in Kickstart. If all the crashes
are occurring within kickstart memory, that suggests that the
Accelerator has trouble accessing kickstart memory. But then,
why do the gurus always occur in the 200000 range?
If nothing else, this should be an interesting conundrum for you
gurus out there to think about. Is the problem in the software, the
Amiga, the Ronin, or perhaps the Comspec memory? Is there any way
to fix it that won't cost me lots of money? Please write if you
have suggestions; I can give further details. (I've kept statistics
on what programs have given what gurus.)
---
It may be that this ancient Amiga simply won't be able to accept
an accelerator card due to its early pre-halfbrite design (gee,
thanks, You who Sold it to Me). Therefore: if anyone out there
would like to trade a fast hard disk system for a really fast
accelerator card, send me a message. I can't give any more
warranty than I got ("Sure it'll work. Just ground the PALs.
Oh, you grounded the PALs? You probably destroyed the machine
then."), but you're welcome to test it in your own machine first
(another option I didn't have).
- Ranjit
"If you see the Guru in the road, kill him!"
"Hitting the Guru at 20 MHz is like hitting a speed
bump at 80 MPH."
"Trespassers w" ranjit@eniac.seas.upenn.edu mailrus!eecae!netnews!eniac!...
"Such a brute that even his shadow breaks things." (Lorca)