Re: 4032 ROM add-on

From: Hans Liss <Hans_at_Liss.pp.se>
Date: Sat, 1 Jun 2019 00:15:01 +0200
Message-ID: <8672fd44-4c46-e8c9-fe95-f5f0b89a9a1e_at_Liss.pp.se>
I started disassembling it and found very little. Not knowing enough
about the PET is a bit of a problem. :)

Still, there's code at $95fd that resembles a simple one-letter command
handler for commands like 'A', 'D', 'O', 'T', 'S', 'R', 'H','V','M','N'.

Also, at $92a4, there's a string containing 'CLR<Return>', which is
loaded by a routine at $9280 and used for who knows what, possibly
pushed onto an input queue or something like that.

I thought it might be a machine code monitor but I haven't found any ROM
images online that resemble this one - not even a little.

/Hans

On 2019-05-31 15:38, Francesco Messineo wrote:
> Hi all,
> I'm repairing a 2001N-32 that has Basic 4.0 upgrade (all EPROMs
> instead of ROMs).
> I've also found an additional ROM in the $9000 socket, the only string
> that seems to be in the image is "BASIC 4.5". I've attached the ROM
> dump, does anyone know what it is and how to activate it?
> Thanks


Received on 2020-05-29 21:59:31

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