twgs vs. zip

[fmlin@cyberden.uucp]

I thought I should post my upgrade, since
 
1. We're talking about TWGS vs. ZIP... :)
 
2. I thought you guys might be interested in the results of my
upgrade.
 
3. I happen to have differt crystals, and I decided to ( am I bored
or what :) actually test each out...
 
The tests were done under System 6 with no inits.  Dhrystone &
Benchmark launched under ORCA/Shell v2.0.  twgs's AppleTalk/IRQ off (
me and Chris seems to be the lucky ones ).  Benchmark results were
averaged out of 3 rounds.
 
type       stock   twgs   twgs   twgs   twgs   twgs   twgs   twgs
clock spd  2.8mhz  7      8.33   9      10     12.5   13.75  15
cache/spd          32k-15 32k-15 32k-15 32k-15 32k-35 32k-15 32k-15
           ======= ====== ====== ====== ====== ====== ====== ======
Sieve       409.00 178.00 150.67 143.00 134.00 117.00 107.00 100.33
String     1148.67 478.33 414.67 391.00 356.33 306.00 293.00 270.33
FPE Test 1  471.00 186.00 157.33 146.00 132.00 107.33  99.33  93.00
FPE Test 2 1531.67 612.00 520.67 485.67 442.00 363.67 337.00 315.00
Fabinacci  2001.67 891.00 794.00 768.33 724.67 645.00 627.33 603.00
Integer    1550.33 586.67 497.00  64.00 422.00 347.00 326.67 307.33
Average             x6.34  x7.4   x7.86  x8.57  x10.14 x10.81 x11.56
 
Dhrystone  245     609    724    769    847    943    1000   1086
1136
 
Voltage                                         5v     5.4v   5.6v
 
ROM v1.8s, Paradigm 15ns SRAMs
GALs - 1A 2B 3E 4B 5A 6A 7A 8B ( stock )
ROM 01, RF 3.0h D in slot 2, TWGS in slot 4, and LRO/S&S DMA 4mb
Shmoo plot suggested 12.5mhz @ 5v, 13.75mhz @ 5.5v, and 15mhz @ 6v
 
Chris's TWGS gets 1250 dhrystones/sec. at 15mhz.  My Fabinacci seems
to be extra slow! ( Chris' gets about 505 @ 15mhz ).  Chris also got
some 64mhz chrystals; about 16mhz!! ( urr, I want to try these on my
:)
 
The 15ns didn't help at all with performace.  But the cache RAM &
cache flush tests will now pass at 15mhz, definetely helped at 15mhz.
If you want to go 13.75 or 15, you should consider 25ns ( should be
fine ), 20ns will be enough.  15ns is a little overkill, but if you
want to be safe, I would suggest it; since you're pushing the CPU at
15mhz.  You must also increase the voltage, because you simply can't
make the chip go 15mhz @ 5v.  The easiest way will be to get the
heavy duty power supply; someone mentioned cutting some traces, step
the 12v down and stuff...  NOT recommanded, since the alteration is
probably permenent.  Gettin the HD supply is much easier, and adjust
the voltage isn't hard.
 
I also do not recommand going to 13.75mhz or higher because:
 
1. You'll need to get a new power supply.
2. You probably need new SRAMs for 13.75, and you must get new ones
for 15.
3. Performance increase is modest, but noticable.
4. When you get these installed, reliability is not guranteed.
5. You'll spend a lot more money just to TRY!  12.5mhz is easy ( just
swap CPU & crystal ), safe ( stock 5v is fine ), and cheap ( stock
supply, and SRAMs ).
 
But, if you insist on getting the max...
 
I'll talk about my experience with TWGSes.  I had my first one in mid
1990.  It worked flawless for about 1 1/2 years.  Then I decided to
get the 32k cache upgrade.  I cut the wire traces too deep.  I tried
to solder it back, but I made a big mess.  Lucky, I talked to Larry
of LRO, and he took the board back for me, and got it fixed from AE
and only charged me 20 bucks.  I got a brand new board back!!  This
board was flacky, and after a while, I just get stuck at the checker
flag screen.
 
I sent it back to AE, and after about 5-6 weeks, they sent a NEW
board back.  The 900 phone call was 5 bucks, and another $15 for
shipping return coverage.  Not bad...  So, I am on  my 3rd board now.
This one works great, like my first one.  About a month ago, I
brought the new WDC/Sanyo 65816, and I've been running at 13.75mhz
fine for a while.
 
About a week ago, I cut the wires from my old Apple power supply, and
drive my Maxtor from it now; it was getting the power from my floppy
port.  I finally can feed my system with 5.6v.  I've been running at
15mhz for about a week now. No problems in GS/OS.  ProTERM will
sometimes ( 5 - 10 % of the time ) get the inverted "@" in the scroll
back, the clock would move 2 lines down and stay in the scroll back,
and the mouse cursor would move off the right edge of the screen and
come back at the left side ( the exact same problems as Chris
described ).  Other than that, no problems.
 
If you want to reply, please mail me here at fmlin@cyberden.uucp for
now. fmlin@terapin.com is in-accessable for me for about 2 weeks.
Did you guys like the icons I posted at c.b.a2?  It's also on
cco.caltech.edu now.

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   | H E   \ Y B E R |/ E N            [ fmlin@cyberden.uucp ]