[channelf] Re: Cart dumper

  • From: "Sean Riddle" <seanriddle@xxxxxxx>
  • To: <channelf@xxxxxxxxxxxxx>
  • Date: Mon, 2 Jul 2007 11:03:47 -0500

                Scott said I could upload some of the proto dumps, so I put
Galactic Space War, Football, Draw Poker, the partial Demo and the bad
Spitfire in a ZIP file on the web site below.  One time Spitfire came up for
me with slightly garbled graphics, but then it locked up, so I'm guessing
some bits are bad.  Only one of two ROMs on Demo dumped correctly.  If you
notice any differences in gameplay between the prototype and production
games, please let me know.




From: Sean Riddle [mailto:seanriddle@xxxxxxx] 
Sent: Sunday, July 01, 2007 12:50 PM
To: 'channelf@xxxxxxxxxxxxx'
Subject: RE: [channelf] Cart dumper


                I added 3 more pics- the insides of Color Organ, Demo and
Spitfire.  They all have 3853s and ROMs, but he's having trouble dumping the
ROMs with his EPROM burner.  The Maze ROMs seem shot- the cart won't play
and the dumps are bad.




From: Sean Riddle [mailto:seanriddle@xxxxxxx] 
Sent: Sunday, July 01, 2007 4:11 AM
To: 'channelf@xxxxxxxxxxxxx'
Subject: RE: [channelf] Cart dumper


                Right after I sent this email, a guy wrote me and said he
had several prototype carts, asking how to dump them.  Take a look at these
pics: www.datalytixllc.com/channelf


                He was able to successfully read the 2716 EPROMs on 3 of the
carts, but not on Maze.  Speaking of Maze- check out the SL31254 on the
cart!  I wonder why, when that chip is in the console?  It seems like there
would be bus contention if you plugged this into a standard Channel F
console.  He sent me good dumps of proto carts 23, 24 and 25.  They are
similar to but different from the production carts.


                Also check out Math Quiz 1- it uses 2 full-size 40-pin 3851
PSUs instead of just the dies bonded to the PCB like the other carts.


                I've asked him if he can send me the Maze, Color Organ, Demo
and Math Quiz 1 carts so I can dump them with my cart dumper.





From: Sean Riddle [mailto:seanriddle@xxxxxxx] 
Sent: Friday, June 29, 2007 9:12 PM
To: 'channelf@xxxxxxxxxxxxx'
Subject: RE: [channelf] Cart dumper




                I can't find any schematics, but it's not that complicated.
The cart/PSU needs ground, +5 and +12 for power, so I used a 15V "wall wart"
along with 7812 and 7805 voltage regulators.  To reduce heat, the 7812
connects to 15V, and the 7805 connects to the 7812's output.  The PIC is
going to toggle the signals WRITE, PHI, and ROMC3, and it's going to read
the 8-bit data bus.  So I connected PHI to PORTA.1, WRITE to PORTA.2, ROMC3
to PORTA.3 and the data bus to PORTB.  I grounded ROMC0, ROMC1, ROMC2 and
ROMC4.  So I can only generate ROMC states 00 and 08, but that's all I need;
08 clears program counter 0 and 00 is instruction fetch ("the device whose
address space includes the contents of program counter 0 must place on the
data bus the op code addressed by program counter 0; then all devices
increment the contents of program counter 0").  So I clear program counter
0, then do many instruction fetches in a loop.  After each instruction
fetch, I read the data bus and save that into a buffer.


                Of course the PIC needs all the normal stuff- I used a 20MHz
resonator for the clock, and you need the MCLR resistor.  I also used
PORTA.0 as serial output, and I connected an LED to PORTA.3 so I could tell
when the program was done dumping the cart.  Since you won't be sending the
dumper out to other people, the serial port should be fine and you won't
need to add the SEEPROM like I did.  I cut down an ISA slot for the carts to
plug into, and used a 40-pin socket for the PSUs.  Since they use different
address ranges, you should be able to plug both a PSU and a cart in at the
same time, but I never tried it.


                This code is in Pic BASIC Pro.  If you don't have their
compiler, I think you can compile it for free on their web site.  If not,
let me know and I can send you the HEX file the compiler created.


                The Channel F games start at 0x0800, so the first 2,048
bytes of carts will be blank (0xFFs).  The PSUs will start at 0x0000 and
0x0400.  This code will read 256x16=4,096 bytes, which is enough for all
PSUs and most of the carts.  You'll need a hex-editor to strip off the
blanks at the end of the file.





                While I was doing a Google search I came across some
pictures of "prototype Channel F Carts".  Anyone have any?




From: channelf-bounce@xxxxxxxxxxxxx [mailto:channelf-bounce@xxxxxxxxxxxxx]
On Behalf Of Knowles, Ian
Sent: Friday, June 29, 2007 2:56 PM
To: channelf@xxxxxxxxxxxxx
Subject: [channelf] Cart dumper



Sorry for the delay in replying, but yes I'd like to build my own dumper,
schematics and the PIC source code would be great if you can provide them.
Thanks Sean.

Ian Knowles 

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