[comp.sys.cbm] More hard disk madness

seven@nuchat.UUCP (David Paulsen) (10/09/89)

In article <89100603481468@masnet.uucp> iain.bennett@canremote.uucp (IAIN BENNETT) writes:
>I'm here again to clear things /up again!
> 
>The 64 wwas not designed to be used with a hard drive~x_S.  It never
>even was intended for the 1581, but  the '81 was made...shows how
>brainy_ commoxDore is!

True, the 64 was not designed to be used with a hard drive; but then
neither was it designed to address more than 64K of RAM, use any of
the faster IEEE peripherals, drive MIDI synthesizers or burn eproms..
yet it does all of these things and countless more.  When the 64 was
conceived, even "real" personal computers rarely had hard drives.

I think the 64 can make good use of a hard disk, even if it was
interfaced through the serial port.  As for the 1581 disk drive,
I own two of them.. both happily plugged into my 64.

>sorry for the line noise.
> 
>Now for hard drives.  the 64 is too slow in my opinion1yG.  Also adding
>an IBM hard drive, you would have to fooormat in special ways.  Do you
>unxBerstand what I'm getting at?

A hard disk is a peripheral, to be used by the computer... not the other
way around.  So WHAT if the disk drive is capable of delivering data
at 4 or 8 times the bus speed of my Commodore 64?  This is immaterial.

Even clone computers do not speak directly to their hard drives.  They
use controller cards, buffers, caches.. all the things found (in a *much*
tinier form :-) inside the 1541.  What I propose is taking some of that
existing 8-bit IBM-PC technology and putting it to work -- cheap -- for
the 64.  "Formatting" is not the issue.  I don't expect to be able to
boot Disk Doctor, nor do I need Fastload to work.  As far as low-level
formatting goes, we can always format the beastie on an IBM, then
unship it for use in the 64 system.  

Various possibilities include:

1. Interface an XT 8-bit hard disk controller to the user port.  

2. Build a cable from the CBM serial [pseudo-IEEE] port to the COM1
   port on an IBM-XT clone.  Have the "big" computer pretend to be
   a 1541, and simulate Commodore DOS.  Set up sub-directories on
   the hard drive for Pac-Man and Paperclip64.  (Eventually get the
   8088/1541-emulation software down to a TSR, so you can run it as
   a background task all the time.)

3. Canibalize a 64; turn it into a dedicated hard drive controller.
   (Why not?  8-bit user port, 64K ram, 6502-ish processor.. should
   make a dandy controller.  Write the DOS in BASIC!)  Interface the
   modified C64 to another C64 via their CBM serial ports.

4. Modify a 1764 REU cartridge so that some of the external memory
   is shared by the hard disk controller.  Copy data into the
   shared memory, swap it into the 64's memory map at blinding
   speed.

While I applaud the Total Concept embraced by the Xetec hard drive
systems, I cringe at their prices.  I don't NEED 100% compatibility
or blinding speed... I have my 1541 for the former, and an REU for
the latter.  

> %dE
>
> * QNet 1.04a1: MCS BBS, Milton, On., Canada, (416)878-5935 (19200 HST)

David

-- 
David Paulsen    ..uunet!nuchat!seven  ||| The Curiosity Shop BBS, 713/488-7836
-------------------------------------------------------------------------------
   The spirit is free / Where the wild things roam
   Next to the sea / The electric ocean              [The Cult]

ewm@cbnews.ATT.COM (edward.w.mcfarland) (10/10/89)

In article <15457@nuchat.UUCP> seven@nuchat.UUCP (David Paulsen) writes:

>I think the 64 can make good use of a hard disk, even if it was
>interfaced through the serial port. 

>Even clone computers do not speak directly to their hard drives.  They
>use controller cards, buffers, caches.. all the things found (in a *much*
                                         ^^^^^^^^^^^^^^^^^^^^
>tinier form :-) inside the 1541.  What I propose is taking some of that
                 ^^^^^^^^^^^^^^^^
>existing 8-bit IBM-PC technology and putting it to work -- cheap -- for
>the 64.  "Formatting" is not the issue.  I don't expect to be able to
>boot Disk Doctor, nor do I need Fastload to work.  As far as low-level
>formatting goes, we can always format the beastie on an IBM, then
>unship it for use in the 64 system.  

>Various possibilities include:
                                (4 possibilities deleted)

>While I applaud the Total Concept embraced by the Xetec hard drive
>systems, I cringe at their prices.  I don't NEED 100% compatibility
>or blinding speed... I have my 1541 for the former, and an REU for
>the latter.  

My feelings as well.

>David Paulsen    ..uunet!nuchat!seven  ||| The Curiosity Shop BBS, 713/488-7836


     I am fairly ignorant at the nuts and bolts level of the hardware but, 
what about cannibalizing a 1541 drive to use as a controller for commonly
available pc harddrives? What would be involved in hacking an interface board
together so one could substitute a hard drive in place of the floppy drive?
Is this harder to do than it seems? I wouldn't mind cannibalizing my 1541
to gain a hard drive. (it would be the incentive I need to get a 1571 or 81)
What about cannibalizing a 1581? Is the hardware there any more conducive?
I'd bet this could be done for less than the $700+ that Xetec charges.

    How about it you hardware types, is this possible/worthwhile?


-----------------------------------------
    Ed McFarland     ewm@mvusa.att.com  |
-----------------------------------------

seven@nuchat.UUCP (David Paulsen) (10/11/89)

In article <10046@cbnews.ATT.COM> ewm@cbnews.ATT.COM (edward.w.mcfarland,54723,mv,30-2 W3,508 960 6202) writes:
>In article <15457@nuchat.UUCP> seven@nuchat.UUCP (David Paulsen) writes:
>
>>I think the 64 can make good use of a hard disk, even if it was
>>interfaced through the serial port. 
>
>...what about cannibalizing a 1541 drive to use as a controller for commonly
>available pc harddrives? What would be involved in hacking an interface board
>together so one could substitute a hard drive in place of the floppy drive?
>Is this harder to do than it seems? I wouldn't mind cannibalizing my 1541
>to gain a hard drive. 

Neither would I.  But alas..

I'm not a hardware type, but I don't think it's possible to swap out the
floppy drive for a hard drive and make it work.  Even radical rewriting 
of the 1541 operating system wouldn't provide the hard drive with the
signals it needs.

However, perhaps the 1541's RAM could be patched into.. an external 
hard disk would read/write sectors to the 1541's buffers directly,
for transmission over the CBM serial bus.  By sending a special
"read hard disk buffer" (U5: ?) command you could access data the
same way you would by direct-disk access on a 1541.

To make things easier, an additional 3K of ram -- 3072 bytes --
can be added to the 1541 memory map to allow for extra buffers
and programming space.  (This I read in the _Transactor_ a couple
of years ago.. anyone try it?)

While I think this could work, and in fact I'm all for a 1541/20MB
hard drive combo, I'm still partial to the 1764 REU modification
scheme.. programming on the 64 side would be soooo much easier.
Not to mention the near-instantaneous speed that could be attained.

>What about cannibalizing a 1581? Is the hardware there any more conducive?
>I'd bet this could be done for less than the $700+ that Xetec charges.

The same basic impediments exist for the 1581.. perhaps more, since
there are dozens of books that address 1541 hacking and almost nothing
for the 1581.  In any case, I KNOW we can beat the $700+ barrier using 
baling wire and coat hangars.  And now, I zip off on a tangent...

Re: external hard drives in general

Why so expensive?  I always bought the party line, that the external
power supply, case and controller card drove the price up.. but
recently I've been reading the _Computer Shopper_ and noting the
prices I see.. at the mail-order level everything appears to be
available for dirt cheap.  Power supplies for $29.  External hard
drive cases, $49.  Controllers (IBM-XT compatible): $69.  Rebuilt
5MB Tandon harddrive, $75.  We're talking under $225 in parts..
and I'm randomly thumbing thru this magazine, typing the first
prices I see!  I realize this is hardly a realistic approach, but
as an experiment it's illuminating; if you assume the (conservative)
price of $700 for the Xetec unit, that's a 315% markup.  Quite
the racket, wouldn't you say?

I also realize that the Xetec drive systems represent "years of
research", and address the average Commodore owner's desires: fast
loads, ease of use, compatibility.  But the price is clearly too
high.. or else we'd ALL have the damn things sitting next to our
1541s!  Where's the "Xetec Bare Bones 1000, the Hard Drive For The
Rest Of Us" ..retail $399?

Am I totally naive here?


>-----------------------------------------
>    Ed McFarland     ewm@mvusa.att.com  |
>-----------------------------------------

David

-- 
David Paulsen    ..uunet!nuchat!seven  ||| The Curiosity Shop BBS, 713/488-7836
-------------------------------------------------------------------------------
   The spirit is free / Where the wild things roam
   Next to the sea / The electric ocean              [The Cult]