Path: utzoo!attcan!uunet!mcvax!ukc!cs.tcd.ie!csvax1!ecarroll
From: ecarroll@cs.tcd.ie (Eddy Carroll)
Newsgroups: comp.sys.cbm
Subject: Re: Parallel Disk Interface
Message-ID: <30462@cs.tcd.ie>
Date: 7 Jan 89 21:02:26 GMT
References: <420@manta.NOSC.MIL>
Organization: Computer Science Department, Trinity College Dublin
Lines: 46

In article <420@manta.NOSC.MIL>, mitch@manta.NOSC.MIL (Ray Mitchell) writes:
> Does anyone know anything about any modifications to the Commodore 64
> to permit the use of a parallel interface to the disk drive? Anything
> would be appreciated.
> 				Thanks,
> 				Ray Mitchell

Over here in Europe, there are several parallel disk systems available for
the C64/C128 + 1541 drive, giving around a 25 fold increase in speed. I have
Dolphin DOS from Evesham Micros (63 Bridge Street, Evesham, Worcs WR11 4SF,
England, phone England 0386-765500) and am very pleased with it. Typical
loading speeds are around 3-4 seconds for a 50K program file. Most programs
load in less than two seconds. Sequential file access is speeded up 12 times,
as is program saving (as opposed to loading).

The extra speed is achieved by using both a parallel interface and an 8K
track buffer in the 1541. I think I heard somewhere that they also use a
hardware circuit to do the GCR decoding rather than leaving it to the
software. The whole system works with almost everything, and can be switched
out completely for the odd piece of software that doesn't like it. In
addition, you get some other nice extras at the C64 end, such as built in
DOS 5.1 lookalike, mini machine-code monitor, predefined function keys,
extended screen editor, pause mode while scrolling screen and automatic
detection and use of a printer connected to the user port. All of these are
squeezed into the space used by the Tape and RS232 routines on the C64 Kernal
ROM (The C128 version doesn't remove RS232, not sure about tape). If you need
to access RS232 in C64 mode, a switch is provided which allows you to swap
between normal and Dolphin DOS mode.

Finally, you can get some useful disk utilities including a 21 second fast
disk copier, a fast filecopier and a bit nibbler that copies everything I've
thrown at it. 

I can highly recommend this package, which I've been using for around 18
months. It costs 70 Sterling pounds, and I suspect it doesn't work on the
new models of the 1541, but if you can get it you won't regret it. As I
mentioned above, other systems are available, but I have heard that at least
one of these is not terribly reliable (it claims a 60x increase in speed for
example, which is just about impossible given the speed the drive revolves at!)

(I have no association with Evesham Micros, other than as a very satisfied
customer.)
-- 
Eddy Carroll               ----* Genuine MUD Wizard  | "You haven't lived until
INTER: ecarroll@cs.tcd.ie                            |  until you've died in
 UUCP: {..uunet}!mcvax!ukc!cs.tcd.ie!csvax1!ecarroll |  MUD!" - Richard Bartle