Re: [stella] 7800 anyone?

Subject: Re: [stella] 7800 anyone?
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Fri, 12 Jan 2001 14:37:57 +0100
> I recently acquired files of the unreleased protos NTSC Sentinel and Klax
> from Bruce Tomlin. Unfortunately, the are in hex format instead of bin and
I
> need some way of converting them to bin. Also, if anyone knows how to
create
> an A78 header for use with the MESS emulator, I could use that info as
well.

Aladdin has a free version of it's StuffIt Expander for Windows too, which
among other Mac formats can also handle BinHex (hqx) files.

The A78 file header format information was included with the old
stand-alone version of the 7800 emulator. Here is the relevant part
of the documantation:

======
Cart Header:

To work with this emulator ROM images must have this 128 byte cart header at
the start of the raw data. This header allows the emulator to know the
features
of the cart thus preventing you from having to use a bunch of command line
options.

0      Header version     - 1 byte
1..16  "ATARI7800      "  - 16 bytes
17..48 Cart title         - 32 bytes
49..52 data length        - 4 bytes
53..54 cart type          - 2 bytes
    bit 0 - Pokey cart
    bit 1 - Supercart bank switched
    bit 2 - Supercart RAM
55     controller 1 type  - 1 byte
56     controller 2 type  - 1 byte
    0 = None
    1 = Joystick
    2 = Light Gun

100..127 "ACTUAL CART DATA STARTS HERE" - 28 bytes
=====

Dan might have defined some more bits in the cart-type byte by now though,
to allow support for more bankswitching schemes or PAL games.

If you have an assembler that allows you to include binaries from
the source code, like DASM 2.12.04, you could write some simple
code that defines the nessessary header bytes and then includes the
desired binary. Then you could compile that into a proper A78 file.


Ciao, Eckahrd Stolberg



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