[comp.sys.apple] Review of the RocketChip Accelerator

jac@paul.rutgers.edu (Jonathan A. Chandross) (01/12/89)

This article contains a review of the RocketChip.

For those of you who aren't familiar with the RocketChip, it is much like the 
Zip Chip, only faster.  In fact, the RocketChip was designed by the same guy 
who did the Zip Chip.  Like the Zip Chip, the RocketChip has been on the 
``available real soon now'' list for several months.  I originally ordered mine
around Thanksgiving.  I received it today and spent some time playing around
with it.

The first thing you'll see upon examining the box a list of features.  I've
augmented the following list somewhat with a few others of interest.
	- Runs from 50 KHz to 5 MHz
	- Replaces original 6502 or 65C02
	- Works in ][+, ][e, ][c
	- Emulates AE Transwarp speed setting protocol
	- Accelerates all memory locations
		- system memory (64K or 128K)
		- Auxiliary memory up to 1.6 Megabytes
		- Expansion ROMs
		- Peripheral ROMs
	- Accelerates all 80 column card operations
	- Cache enabled/disabled on a slot by slot basis
	- Acceleration enabled/disabled on a slot by slot basis

What you get
------------
The RocketChip comes with a twelve page photocopied manual (labeled as
``Preliminary, November 1988'') and a disk.  About half of the manual is
installation instructions, with pictures, for the various members of the Apple
][ family.  As far as actually using the RocketChip, the documentation is
adequate - barely.  The warranty card enclosed states that a menu driven
configuration program will be mailed to all registered users when it becomes
available.  The chip itself is a 40 pin package about three times the standard
dip thickness.  The bottom shows epoxy, leading me to believe that the
RocketChip is constructed from unpackaged integrated circuits mounted on a
special PC board, and potted for protection.  I wasn't about to open it up to
verify my conclusions, though.  (But I may call the company.)

Installation
------------
Installation is a breeze.  All you do is unplug the existing 6502 or 65C02,
depending upon the machine, and replace it with the RocketChip.  Even a
hardware novice should be able to manage this without any difficulty.

Configuration
------------
A variety of the features can be enabled/disabled from either the disk or
from the keyboard.  Keyboard commands include speed, pause after reset, and 
cold boot.  The basic syntax is a control-reset followed by a single character.
Speed is settable to either 1 MHz or 5 MHz.  For other speeds and features 
you'll have to use one of the programs on the disk.  All non-standard 
configurations are lost when the power is turned off.

The programs supplied on the disk allow you to set:
	- Speed (5 MHz,4 MHz,3 MHz,2 MHz,1 MHz,500 KHz,250 KHz,100 KHz,50 KHz)
	  audio (normal, silent, distorted, music, hifi).  
	- pause/no pause after reset	
	- transwarp protocol enable/disable
	- language card type
	- boot/no-boot on control-reset
	- acceleration for each slot (on/off)
	- caching for each slot (on/off)
	- caching for expansion roms (on/off)
I'll explain each of these in turn.

Speed
-----
The "music" and "hifi" speed programs slow down the RocketChip for games and
other programs that use the on-board speaker.  As I mentioned above, you can
set the speed from the keyboard using a control-reset ESCAPE (1 Mhz) or
control-reset RETURN (previously set speed, if any, or 5 MHz).  It is unclear
how to get speeds other than what is provided on disk.  (One might want
other speeds for games.)

Pause on Reset
--------------
A pause-on-reset feature provides a 2 second pause following the control-
reset.  This feature can be turned on/off by running a program or via the 
keyboard.  The default is on, and provides an eerie "oh no, I blew up my
apple" when you first turn on the machine after installing the RocketChip
and absolutely nothing happens.  Just when you really start to panic the 
drive starts chattering away.

Control Reset
-------------
Control-Reset works in several different ways depending upon the current
configuration of your hardware and of the RocketChip.  By default, control-
reset causes a reboot if you don't have either paddles or a joystick installed.
Installing a joystick or paddles causes control-reset to work in the normal
way.  However, the reboot feature can be turned on/off with a program on the
supplied disk.  I tried out the various options (no joystick, running the 
program, etc) and everything worked as advertised.

Cold Boot
---------
You can cold-boot your machine using either an open apple or a keyboard command.

Acceleration
------------
The floppy controller must run at 1 MHz as must certain CP/M cards and any
cards that employ DMA.  It doesn't specify which, but I do know that the 
Microsoft CP/M card is very sensitive to timing variations, both from personal
experience and from the design of the ][e. 

Caching
-------
You can cache 80 column cards, and most other cards with on-board ROMS.  There
is on exception to this rule:  the RocketChip cannot cache the Apple SCSI, AE
Ramfactor, or any card that bank-switches ROMs (like the Saturn, Titan and
SwyftCard RAM disks).  This makes sense as the RocketChip has no way of knowing
whether the ROMS are banked out or not.  (It would have to know how each card
worked in great detail since ROM switching is done using hardware and is not
under RocketChip control.)  This renders my Ramfactor and Saturn card pretty
useless, but I doubt that the AE Transwarp would act any differently.

So how fast is it?
------------------
Since I don't have a timer other than my watch I really have no way to time 
any of the tests I performed, and I have to go by the published times that 
I quote below.  However, I can provide some qualitative judgements and will 
do so.

The 5 MHz operation is likely to speed up computation by about 5 times from
the tests I ran (simple loops, a few lisp programs, etc.) However, one might 
wonder how well it works on I/O operations that use the I/O cards, like 80 
column card manipulation.

Acceleration makes a BIG difference to 80 column operations.  I discovered
that the Videx 80 column card is actually usable when accelerated.  The speed
difference is clearly evident for operations like outputting to the screen
and scrolling.  You won't believe how fast the screen updates.  The annoying
Videx flicker under heavy screen update is still there (I think it's a hardware
conflict between hardware screen update and the character output to the video 
screen.) Adding caching was less dramatic, but still helped performance.

One of the programs I ran was a Lisp program that solves the Tower of Hanoi 
problem using LoRes graphics.  The speed increase was amazing -- from 
pathetically slow to usable.  In fact, the speedup allowed me to see when
the Lisp was garbage collecting (graphics stopped for a second), something 
I never could see before since the whole program was so slow.

Well, that's enough of unsubstantiated speed claims.

The following table is lifted, without permission, from the November 19988
issue of inCider.  I've computed the performance of the RocketChip using the
numbers for a 4 MHz Zip Chip and a 5 MHz Rocket Chip.  This means that the
Rocket Chip's execution time will be 75% of the Zip Chip.  Please take these
numbers with a big grain of salt since the cache sizes for the Zip and 
RocketChips are probably different (RocketChip is likely to be larger).

Word Processor:
	500 search and replace repetitions in AppleWorks' word processor
Spreadsheet:
	Recalculate a 1000 cell spreadsheet

------------------------------------------|-----------------
				    Word  |
Machine				 Processor| Spreadsheet
------------------------------------------|-----------------
RocketChip (in ][e) 		   15.2   |   8.2	(COMPUTED)
Apple IIc Plus (fast)		   19.7   |  10.4
Zip Chip (in Apple ][e) 	   20.2   |  10.9
Laser 128EX/2 (fast)		   21.0   |  11.4
Apple ][gs (fast)		   25.0   |  14.5
Apple ][c Plus (slow)		   66.9   |  34.9
Apple ][c			   67.7   |  35.4
Laser 128EX/2 (slow)		   70.2   |  38.1


It appears that the RocketChip is indeed the fastest game in town, coming in at
roughly 60% faster than the Apple ][gs.  Of course, this is only for 8 bit
operations, and this is not really a fair comparison.  However, it IS the
fastest game in town for a no-slot speed booster.  The configuration software
isn't bad, and the promise of a new menu-driven one sounds like an honest one.
The ability to cache and accelerate on a slot by slot basis is a very powerful
one, and will insure that naughty cards that rely on processor speed work as
they should.  From personal experience I can say that the acceleration of the
80 column board made a very big difference.  I recomend, without reservations, 
the RocketChip to anyone who uses their apple for anything other than playing 
sound filled games.

The RocketChip is available form:
	Bits & Pieces Technology, Inc.
	31332 Via Colinas, Suite 112
	Westlake Village, California, 91362

I purchased mine from:
	Quality Computers
	15102 Charlevoix Avenue
	Grosse Point Park, Michigan, 48230
	313-331-0700 (technical questions)
	800-443-6697 (sales.  They take MC/Visa)

	Price:	 179.00		(same as Zip Chip)
	Shipping:  5.00

I am very pleased with Quality Computers.  When I originally placed my order
they told me that the chips were not available yet, but if I wanted they would
put me on a waiting list so I could get one shipped as soon as they came in. 
Someone called several times over the next two months to assure me that my order
was still in the works, and that the chips were expected the week after 
Christmas.  A week ago I got a call that my order had been shipped, and it
finally came today.  I think that this sort of service should be rewarded with
further business.

Note: I have no connection with either Quality Computers or with Bits & Pieces
Technology other than as a satisfied consumer. 


Jonathan A. Chandross
ARPA: jac@paul.rutgers.edu
UUCP: rutgers!jac@paul.rutgers.edu