Path: utzoo!attcan!uunet!husc6!bloom-beacon!tut.cis.ohio-state.edu!mailrus!umix!nancy!nick!sumrall
From: sumrall@nick.egr.msu.edu (Kenneth Sumrall)
Newsgroups: comp.sys.atari.8bit
Subject: Re: 2600 games on the 8bit?
Summary: NO WAY!
Keywords: different hardware, similiar processor
Message-ID: <438@nancy.UUCP>
Date: 19 May 88 04:06:21 GMT
References: <330@umn-d-ub.D.UMN.EDU> <1291@udccvax1.acs.udel.EDU>
Sender: usenet@nancy.UUCP
Reply-To: sumrall@nick.UUCP (Kenneth Sumrall)
Followup-To: comp.sys.atari.8bit
Organization: Engineering, Michigan State Univ., E. Lansing
Lines: 34

In article <1291@udccvax1.acs.udel.EDU> gdtltr@vax1.acs.udel.EDU (Gary D Duzan) writes:
>In article <330@umn-d-ub.D.UMN.EDU> rzimbins@ub.UUCP (robert zimbinski) writes:
>>
>>    Is it possible to convert an Atari 2600 game cartidge to work on an 8bit
>>    machine (specifically an 800)? 
>
>   As I understand it, the 2600 has a completely different microprocessor
>than the computers (I don't know what it has). While I have not heard that 
>the code cannot be converted, I tend to doubt that it can be done easily.
>

The way I heard it, the designer of the 2600 and 8bit video chips
were the same person.  However, I also know that they are very different
machines.  The 2600 CPU is a 6507 I think.  I might have the number wrong
but it is essentially a scaled down version of the 6502 in the 8bit.  It
only addresses 8K of memory, it's missing some interupts, etc.  The 2600 also
has only 256 BYTES of RAM.  There is no stack, so no subroutines are
allowed.  There is also no video screen memory.  The program must constantly
draw the screen and do its work during the Vblank period.  The video chip is
called the TIA, but I have no documentation on how to use it.

Of course, this is quite unlike the 8bit with its wonderful abilities.  
Therefore, it is not possible to move the ROMS between the machines.  
(Then again, most if not all games on the 2600 are also made for the 8bit,
and they probably play a lot better on the 8bit.  So why do you want to
run 2600 games on the 8bit in the first place?)

Kenneth Sumrall
Internet:    sumrall@msudoc.egr.msu.edu
UUCP:        ...!ihnp4!msudoc!sumrall
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*Of course, given enough monkeys and enough time, and enough reams of typing*
*paper, it is possible for any program to be written, no matter how complex.*
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