Re: apple 2e questions

[dempson@atlantis.actrix.gen.nz (David Empson)]

In article <DI6A21.Hz7.0.queen@torfree.net>,
David Arnett <bo144@torfree.net> wrote:
> I just purchased a cheap enhanced IIe to replace my un-enhanced one & it 
> leads to several questions.
> 
> 1) I read that a revision A motherboard cannot display DHIRES graphics.  
>    My enhanced is an -A dated 1984; my unenhanced is a -B dated 1982.
>    Does this mean that apple continued making -A boards 2 years after
>    they made -B?  Will the new one display DHIRES?

It is a different "A".  I think you'll find that the actual board
number changed.

It is only the original US IIe with the revision A motherboard (1982)
that doesn't support double hi-res.

> 2) The self-test displays "RAM    0 0 0 0 0 0 0 1 "  & the computer crashes
>    booting Prodos.  Does this mean there is bad RAM?  If so, which chip?

The obvious answer would be the one in the position indicated by the
"1" digit (rightmost).  I don't know for sure.  It will certainly be
the RAM chip at either end of the row of chips.

> 3) If because of either 1) or 2) above I decide to simply transfer the
>    enhancement chips to my old IIe, can you tell me which 4 chips to
>    swap?  I know the 65C02.  Are the other 3 the VIDEO ROM, CD ROM
>    and EF ROM?

Yes.

> 4) The IIe came with an I/O CONTROLLER 655-0101-B running a DUO DISK.
>    Will this controller work with a 3 1/2 " drive?

No.  I haven't actually seen the card, but it is probably the
UniDisk/DuoDisk 5.25 Controller.  It has the same basic design as the
original Disk ][ Controller, the only difference being the connector
(ribbon cable to a single D-19, instead of two 20-pin male plugs on
the card).

These cards cannot support a 3.5" drive.  To use a 3.5" drive on a
IIe, you need any of:

- An "Apple 3.5 Floppy Disk Drive Interface Card" (a.k.a. "Liron",
  which is written on the back).  This only supports the UniDisk 3.5.

- A "Universal Disk Controller" (from Central Point Software, not sold
  any more).  This supports the Apple 3.5 Drive, 5.25" drives and some
  older Macintosh 400K and 800K drives.  It does not support the UniDisk
  3.5, and if you connect a SuperDrive it will only be able to access
  800K disks.

- An "Apple II 3.5 Disk Controller Card" (a.k.a. "SuperDrive card").  This
  supports the UniDisk 3.5, Apple 3.5 Drive and SuperDrive.  It does
  not support 5.25" drives.

- ABC Direct's rumoured clone of the SuperDrive card, presumably with the
  same set of supported drives.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand