Subject: Fwd: Re: 8250 LP Double disk drive for the commodore 64

From: "Lance S" <[email-masked]>
Date: Wed Jul 2 19:40:20 2003

The reason that I'm looking for it is that my father has been using his 8250 
to run some software and his has broken. He's had a technichian look at it 
and some parts are needed. It would be easier to buy another.

As I understand, 1541 drives read / write in a different format to the 8250 
drives. The 8250 is able to write 1Mb to each disk which I don't think the 
1541 can do.

Lance.

----Original Message Follows----
From: Ethan Dicks <[email-masked]>
Reply-To: [email-masked]
To: [email-masked]
Subject: Re: 8250 LP Double disk drive for the commodore 64
Date: Wed, 2 Jul 2003 11:06:55 -0700 (PDT)

--- Gary Dean Hildebrand <[email-masked]> wrote:
 > Lance S writes:
 >
 > > I am looking for an 8250 LP Double disk drive for the commodore 64.
 >
 > Why do you want that drive?

Maybe he has some 8250 disks to read?  Perhaps some (custom?) software that
needs a disk larger than a 1541 to work?

 > It is designed for the PET series, and has
 > the full blown IEEE-488 interface, which the C=64 lacks.

He didn't say, but he could have one already.  I have one for the C-64 and
one for the VIC-20.

 > So you'd need the adapter on the 64 as well, and I bet they are harder to
 > find than WMD in Iraq..

It's possible to build your own with a VLSI I/O chip (6520/6522/6526)
and a couple of buffers.  That plus a ROM is what's on my VIC-20 IEEE
adapter.  IIRC, the drivers are a 75160/75161 pair, but there are a
couple of options.

AFAIK, there is firmware for _some_ IEEE adapter on funet.  Not sure
which one without looking.

 > I'd just get a couple of 1541's and daisy chain them together on the
 > port, along with the printer or printer adapter.  If you're wanting
 > double sided disks, then go with a 128 and 1571 drives, and then you can
 > play cp/m as well.

If he wants to move up to a 128, that would work.  Personally, I _have_
a 128, and I'm more likely to fire up a C-64 that it, largely due to
experience and personal comfort.

-ethan

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---

From: Ethan Dicks <[email-masked]>
Date: Sat Jul 5 15:39:19 2003

--- Lance S <[email-masked]> wrote:
> The reason that I'm looking for it is that my father has been using his
> 8250 to run some software and his has broken. He's had a technichian
> look at it and some parts are needed. It would be easier to buy another.

What parts?  Drives?  Power Supply?  Main board?  The main board is
about the only thing that really is hard to replace.

I don't know what specific disk drives shipped with the 8250LP, but if
it's the drives themselves, it's probably possible to find an equivalent.

> As I understand, 1541 drives read / write in a different format to the
> 8250 drives. 

You do have the nub of it.  Completely incompatible.

> The 8250 is able to write 1Mb to each disk which I don't think
> the 1541 can do.

The 1541 has half the tracks and half the heads (and less than 25%
total space per diskette)

Good luck in your search.  All of my PET hardware is older than that.
I have never even seen one up close, but they are out there.

-ethan

---

From: [email-masked] (Tony Duell)
Date: Sat Jul 5 15:44:30 2003

> about the only thing that really is hard to replace.

Err, the main board is not something you replace. It's something you 
_repair_. Most of the chips on it are not hard to find...

Incidentally, if said technician doesn't realise this, it's time he 
started looking for another job!

> it's the drives themselves, it's probably possible to find an equivalent.

Be careful, the drives are a bit strange. For one thing, I think they 
might be the 100tpi (not 96tpi) units. For another they have no 
electronics with them -- there's a little PCB between the drives that 
carries the read/write electronics, stepper driver, etc. A normal drive 
will _not_ plug straight in.

> I have never even seen one up close, but they are out there.

I have one. I also have schematics...

-tony