Help with Apple2 clone "Orange Peel"

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Sat Jul 17 16:54:47 2004

>
> This machine is called "Orange Peel", and is packaged as a
> small rectangular box with three slots accessable on one
> end by sliding back the top, and a separate keyboard.
> I believe the machine is running, at least it clears video
> memory to zero (familier '_at_' pattern) on powerup, but goes
> no further - the ROM/RAM configuration seems odd:
>
> The main board contains 8 4564 DRAM's along with video
> and I/O circuitry etc.
>
> The CPU lives on a separate board which is suspended above
> the mainboard on long, hard-to-insert pins.
>
> The CPU board has 7 sockets. At one end is a single 2716
> EPROM chip labled "New boot", near the other end of the
> line is a label on the board which reads "2kb/2716" - this
> suggests that the whole line should be ROM's (which would
> be consistant with other apples), however the remaining
> sockets contain 5517 CMOS RAM's !!! - clearly there is no
> other code on this board.
>
> Inside the "New Boot" ROM, the only strings I can see are:
>
> FBPASIC OR INTBASIC FILE REQUIRED
> INSERT APPLICATION DISC AND PRESS ESC
>
> This suggests that it loads basic from disk and would not
> have it in ROM.
>
> So - I have a bit of a paradox : the "2kb/2716" label suggests
> ROM's, and the 64k of RAM on the mainboard also indicates that
> all the RAM is on the lower board, however the ROM strings
> suggest that this may be the only ROM.

IIRC, a real Apple ][ has up to 64K RAM (48K on the mainboard, 16K on a
language card) and some ROMs. The ROMs are bank-switched with the top 16K
(Language card) RAM.

It sounds like you effectively have a built-in language card (that would
be quite sensible), and you have RAM in place of the ROM (possibly to get
round Apple copyrights). The 5517 RAMs take the place of ROMs -- they're
loaded once on boot-up, and then contain the resident BASIC, etc. The
EPROM you have sounds like a bootloader for these RAMs.

-tony
Received on Sat Jul 17 2004 - 16:54:47 BST