Skunkboard v5 FAQ and Technical Support Thread

[+cubanismo]

Please use this thread if you have general questions about how to use your Skunkboard, what it is capable of, or need help troubleshooting issues.

 

First, required reading:

 

The manual: skunk_manual-1.0.pdf

Latest JCP installers and source: skunk_jcp on github.com

 

FAQ:

 

• How and Where can I order one?
  • Just reply to the ordering thread
• How much does it cost?
  • $120 + shipping/taxes. See the ordering thread for details.
• OK, I replied saying I want one. What happens now? How do I pay? When will I get it?
  • I am building each board by hand, so it will take some time to fulfill the orders. When your board is nearly ready, I will send you a personal message on the forums asking for your shipping information and paypal email, and use this information to generate a paypal invoice for you. Once paid, I will ship the board. Do not leave your personal information in public posts on the forum! If you want to know your place in line, send me a PM.
• Does it include a USB cable?
  • No! You must supply your own USB cable to connect the board to a computer before you can use your Skunkboard. Specifically, you need a USB-A <-> USB mini-B cable. Here are a few very reasonably priced ones from Amazon: 6ft/2m Amazon Basics cable or 10ft/3.3m Monoprice cable. See the manual for more details on choosing the right type of cable and connecting your computer to your Skunkboard.
• How do I use it?
  • Install JCP using the link above and read the manual. It describes how to set up and use the Skunkboard in great detail. However, note you'll need to be relatively familiar with the command line in your operating system. If you're unfamiliar with command line usage on your OS, this wiki page has some tutorials for the operating systems supported by JCP (Windows, macOS, and Linux).
• Can I use it to play commercial games?
  • Yes, all the original run games, with the exception of the first version of Raiden, should run fine when flashed to the Skunkboard, so if you have legally acquired ROM dumps of these games, you can play them using the board. The Skunkboard detects and refuses to run a very few later releases, and some later releases will not be compatible, either due to their own DRM mechanisms or other issues. See the manual for instructions on how to flash ROMs to the board. That being said, running commercial games on the Skunkboard is not officially supported.
• Can I use it to play homebrew games?
  • Now we're talking! Yes, this is a great use of the board. Depending on the type of release (ROM, .cof, .abs, etc.), homebrew games can be uploaded to the board's flash memory and run from there even after disconnecting the host computer, or uploaded directly to the Jaguar's RAM for one-time runs. See the manual for instructions on how to flash ROMs to the Skunkboard or upload other files to the Jaguar's RAM.
• Are save games/game saves/high-scores supported?
  • Yes! Rev.5 of the Skunkboard includes both a 128B serial EEPROM, like those used on all the original Jaguar releases, and a 2048B serial EEPROM, like those used on some newer releases that are used to save high scores and game progress by some games. You can swap the contents of the serial EEPROMs in/out using JCP just like you can for the main flash memory, and select between the two ROMs from the Skunkboard boot screen or using JCP. See the manual for more details.
• Can I plug it in to my Jaguar CD?
  • Yes, the Skunkboard supports running from the cartridge slot of a Jaguar CD unit. A select few ROMs have been found to not work in this configuration, but in general things should work fine.
• Does it run CD games?
  • No, there is currently no Jaguar CD unit emulation capability.
• Does it work with the JagLink/JagLink 2/Catbox/Scatbox/Jaguar networking in general?
  • Yes.
• Does it work with the Team Tap Multiplayer Adapter?
  • Yes.
• What is the difference between the various versions of the Skunkboard?
  • Rev.1: 4MB flash (No 6MB ROM support, only one bank), susceptible to getting fried by crappy Jaguar power adapters.
  • Rev.2: 8MB flash (6MB ROM support, or two 4MB banks), susceptible to getting fried by crappy Jaguar power adapters.
  • Rev.3: 8MB flash, not susceptible to getting fried by crappy Jaguar power adapters.
  • Rev.4: 8MB flash, one 93C46/128B serial EEPROM for save games.
  • Rev.5 (the one I'm selling): 8MB flash, one 93C46/128B serial EEPROM and one 93C86/2048B serial EEPROM for save games.
• I want to make a game! How do I get started?
  • Awesome! This is the primary purpose of the Skunkboard: Enabling the development of new Jaguar games. How you get started depends on your technical abilities, how much time you want to put in, and what type of game you want to make. If you want to really dig in to what the Jaguar is, program it at a low level, and squeeze every ounce of performance out of it, you might want to try my low-level Jaguar SDK for Linux. It includes most of the SDK components provided to the original Jaguar developers by Atari, as well as some updated versions of things that no longer work on modern computers, additional documentation, additional examples, etc. Check out the link for more information. If writing assembly or low-level C code sounds daunting, or if you want to actually finish your project, you may be more interested in JagStudio, an excellent all-in-one Jaguar development suite allowing you to quickly create games using BASIC, C, or assembly. Check out the link for more information. Good luck!
• What's the biggest game/ROM I can use with the Skunkboard?
  • You can flash ROMs up to 6MB to the Skunkboard. Or, if you want to make a game that works only on the Skunkboard, you could theoretically divide it into two 4MB ROMs and flash them individually, and use bank switching logic in your code to switch back and forth between each of the 4MB flash banks on the board at runtime.
• I want to build my own Skunkboard. Is this possible?
  • You're crazy. But yes, it is possible. All the source material you'll need is available at the links below. You will also need, at a minimum:
    • A soldering iron, and the ability to solder fine pin-pitch SMT parts. If you're just starting out, get some SMT soldering practice kits from Amazon.
    • A BJL-modified Jaguar. Using a BJL CD in the Jaguar CD won't work unfortunately. See Matthias Domin's BJL modification guide and this forum thread to learn how to perform this modification.
    • A BJL cable or adapter. I don't think anyone sells these anymore, so you'll have to build your own, or, if you ask me really nicely, I might sell you one.
    • A computer with a parallel port. A USB->parallel adapter won't work. It has to be a real parallel port on the motherboard.
    • a 5V or 3.3V bench power supply. I use a mangled USB cable and a USB phone charger and some alligator clips to get a 5V supply. This is used when bringing up the board, specifically to verify USB is functional before flashing the CPLD and when actually flashing the CPLD.
    • Xilinx ISE. This is a pain to install on modern operating systems. Ultimately I found the Linux version a little easier to install. See some of my notes in this forum post.
    • A Xilinx Platform USB Cable II programmer to program the CPLD, or a compatible model. I don't think Xilinx even sells these anymore, and they're quite expensive on eBay, so I use this knock-off one, and it works great.
• Where do I get ROMs/Games?
  • Lot's of places. You might start here, here, or here. If you mean illegal commercial ROM dumps, not here.

 

Source Code/Materials:

• PCB: skunk_pcb
• BOM: SkunkBoard BOM
• CPLD: skunk_butcher
• BIOS: skunk_bios
• Bringup Scripts and Programs: bjlSkunkFlash (Linux Only Version, Windows binaries available here in the Full release package)
• JCP: skunk_jcp
• Packaging/Artwork: skunk_pkg

[swapd0]

One question, skunk board silly venture edition is rev 3 or 4?

 

I've two skunk boards, I think that I've rev2 (it has two USB ports and IIRC I missed the first batch of skunkboards) and silly venture edition, without opening still in the anti-static bag.

 

I've been trying to write the high scores of my games with no luck, but after a lot of googling it looks that my skunk board doesn't have a serial EEPROM chip.

 

Anybody knows if the silly venture edition has a serial EEPROM chip?

 

[+cubanismo]

Silly Venture is Rev 3 from my understanding. It does not have an EEPROM. Rev 2 is more or less functionally equivalent to Rev 3, but susceptible to out-of-spec power supplies burning out the flash chip. Rev 1 is the single-bank 4MB version.

 

Rev 4 boards are the first to have an EEPROM added AFAIK, and are pretty rare. They have blue PCBs. The Zaxon-made skunks from Sellmyretro are Rev 3 boards with an EEPROM added on. I don't know if it was added to the PCB layout like on the Rev 4 boards, or sort of bolted on/modded as described in some old posts here, as I haven't taken the case off mine (it seems to be glued together such that it'd be damaged if I took it apart). I don't have any of the original Rev 1-3 boards, but you can find pictures of the PCBs on Google or YouTube if you look hard enough. I did kind of an excessive amount of research before building my boards.

The Rev 5 boards have 2 EEPROMs, with a little logic to toggle between them in newer versions of the BIOS and JCP.

[+atari2600land]

I am unable to load games onto my Skunkboard. When I try to, I get a whole bunch of error messages: *Skipping block at [ridiculously long number] - not flash! Please help me!

EDIT: I was trying to load my game onto ROM. I loaded my game onto RAM and it works now.

[BlueIn2Red]

I have a question regarding game saving, which I hope isn’t too silly (or covered somewhere I should already have read!). I understand about the two types of EEPROM, but it’s not clear how many games can save in each one - is it just one? So if you have two ROMs stored for example, only one of these can do a save? And if you attempt a save with the “other” game, will it overwrite the save of the first?

 

None of this is an issue, because I can use JCP to download/upload save data as appropriate. I just want to be clear when/if I need to do so. It would be very handy if the two games in the flash banks could both fit their data in the EEPROM at the same time, but I’m guessing that’s not the case?

[+cubanismo]

Correct, one game per eeprom. I agree it's a bit of a hassle to save/restore each time, especially when there are those two banks, but that's what I could pull off with my limited skills and available PCB real estate. I'm hoping to work out some kind of auto save/restore scheme with help from an updated BIOS for my SkunkUSB project, but I haven't worked on that in a while.

[BlueIn2Red]

Understood, thanks for the reply. I think I’ll just set up some batch files to handle the EEPROM file swapping (i.e. at the same time as switching to a new ROM). Easy enough to do really.

 

One other related question actually - is there a way to find out the type (size) of EEPROM a game uses? Or is it just a case of “modern games use the larger size” together with a bit of trial and error?

Edited May 21, 2022 by BlueIn2Red

[+cubanismo]

Yeah, trial and error, or examine the components on the PCB of the game. Picking the wrong one won't harm the hardware. It just won't work and could erase or corrupt the current eeprom content.

 

I believe the MRQ metadata files for the Game Drive have a flag specifying the eeprom size, but I haven't messed with them too much. There's a thread with a bunch of them in the Game Drive subforum.

[JagChris]

1 hour ago, BlueIn2Red said:

Understood, thanks for the reply. I think I’ll just set up some batch files to handle the EEPROM file swapping (i.e. at the same time as switching to a new ROM). Easy enough to do really.

 

One other related question actually - is there a way to find out the type (size) of EEPROM a game uses? Or is it just a case of “modern games use the larger size” together with a bit of trial and error?

You think you would mind sharing that to the public once you finish it?

[BlueIn2Red]

Sure I will do that, although not sure how universal it will be (I won't be doing any fancy parameter stuff, just hardcoding it to my ROMs and my folder structure).

Edited May 21, 2022 by BlueIn2Red

[JagChris]

I guess we could customize the batch script you create to suit our needs or mimic your file structure.