• Timelapse Video of Sega SC-3000 Megacart Assembly... 25 April 2022

  • Timelapse Video of Sega SC-3000 Megacart Assembly... 25 April 2022

    Hi All. I'm still making these things slowly, when I get spare time. Which isn't often :)

    But I've always wanted to do a timelapse showing what it takes to put one of these Sega SC-3000 Megacarts together and the tools I use.

    Spoiler Alert - it took me around 53 minutes to get the cart soldered up, insert the logic chips, trim the cartridge case to fit, and screw it shut. The video runs for about 6 minutes including a few cut scenes with explanations and showing you how my IC chip tester works - that is gold if you work with TTL style logic chips (I should do another video on that - at one stage I was plagued by 74LS labelled chips that were actually 74HC chips in disguise).

    There is lots of other boring stuff that you don't see in the video like gluing the stickers down (they are removeable so you can get at the screws but it means they need extra glue in a couple of places), ordering the parts, testing / identifying broken or counterfeit parts, dealing with emails, burning EPROMs, testing the finished Megacarts, and swearing at the 3D printer that takes another couple of hours per Megacart.


    Sega SC-3000 Survivors MEGACART emulated in MAME / MEKA... 30 May 2019

    Hi All. Thanks to everyone who has bought a Multicart or Megacart over the past few years.

    I'm still building a few of these for any genuine Sega enthusiasts who manage to track me down. But I'm really struggling to find the time to build them. Life is busy.

    So just in case I get hit by a bus, or even if you just want to try out the Megacart before ordering, you can emulate the SC-3000 Survivors Megacart in MAME v0.206 or later and the MK II Multicart in MEKA. Support looks pretty good in MAME out of the box. MEKA struggles a bit with some of the tape software and from memory you have to fiddle around with turning the keyboard on / off and adjusting the joystick settings.

    Sega SC-3000 Megacart emulation in MAME v0.209

    SC-3000 MEGACART in MAME

    Hint - if you aren't used to MAME, then you should find that by default it supports the SC-3000 keyboard and joysticks.

    To open up the MAME menu in game (like in the screenshot), press ScrLk on your keyboard, then the Tab key. To go back to Sega keyboard emulation, press ScrLk again.

    Many thanks to Nigel Barnes for adding support to MAME for the Megacart.

    Sega SC-3000 Mk II Multicart emulation in MEKA

    SC-3000 Mk II Multicart in MEKA

    Bock added support for the Mk II Multicart to Meka back in 2015 to help me with development. That was VERY much appreciated. The Meka debugger rocks, by the way :)

    You should be able to find a build of MEKA somewhere in the Meka 0.80 thread on SMS Power.

    Just download the v2.31 SC-3000 Survivors Megacart / Multicart Binaries, and rename SC3000SurvivorsMkIIMulticart_v2_31.bin to Meka will happily open that and play it

    You will probably need to experiment with turning the Keyboard on / off in Meka to get things working, and not all the tape software works properly. From memory Meka's origin as a console emulator show in that it doesn't handle both joysticks and keyboards simultaneously very well.

    Sega SC-3000 Survivors MEGACART available... 17 May 2018

    SC-3000 Survivors MEGACART (2018)

    I started the original Multicart Project back in 2011, and the Survivors MkII Multicart was released in March 2012. This has been a tribute to a much loved piece of 80s computing history, the wonderful Sega SC-30000 home computer and all the tape software I used as a kid.

    This is not and has never been a commercial operation. It is a spare time hobby, and spare time is increasingly hard to find as your kids are growing up.

    But every few months another random email would turn up from someone pleading for a multicart to return to their childhood, so I kept things ticking over.

    Last year I ran out of the last of the Multicart PCBs and had to decide what to do next.

    So I went back and decided to fix some of the things I wasn't happy with in the original design. The result is the new SC-3000 Survivors MEGACART. The four big changes are:

    Check out how the Megacart IO Port Write detection works on a SG-1000

    New MEGACART Labels by LabelsPlus

    Cool new MEGACART labels by LabelsPlus

    Once again, Labels Plus did a great job on the vinyl sticky labels for these.

    Their website is excellent with an online quoting facility, and all the information you need to create correctly formatted artwork suitable for printing. Their minimum charge has increased from $50 + GST back in 2013 to $80 + GST now, but I think that is still pretty reasonable for 150 custom designed vinyl labels.

    Tape Restoration Project - Dungeons Beneath Cairo Release... 27 Aug 2015

    Dungeons Beneath Cairo by Andrew Flexman and David Harvey of Scorpion Software.

    Neat little 80s D&D RPG style game. This one required a more advanced remastering technique.

    ...see the Dungeons Beneath Cairo tape release for Sega SC-3000

    ...see Remastering Technique #2 used for Dungeons Beneath Cairo

    Sega SP-400 Plotter Pie Chart Demo Video... 26 Aug 2015

    This is Demo #1 from the Sega SP-400 Plotter Printer user manual. It draws a pie chart, colours in the segments, and then draws a legend (again with colours).

    These little plotters are *so* cool to watch - they remind me of watching a 3D printer.

    Right at the end you can also see one of my Sega SC-3000s with a breadboard component video mod. That is a work in progress.

    Sega SP-400 Plotter Printer unboxing and self test... 25 Aug 2015

    After many years I have finally acquired a Sega SP-400 Plotter Printer. I'm like a kid in a candy shop :)

    Back in the early 80s ALPS licensed a small plotter design which was used for home computers by lots of manufacturers like Sharp, Atari, Commodore etc. The SP-400 is Sega's take on the plotter. It has 4 individual pens (black, greed, red blue) with little ballpoints on each one, and the plotter draws by moving the pens left to right as the paper moves up and down.

    I'm lucky that this plotter works, has a full roll of paper, and a pile of spare pens. When I get some time I will write some plotter demos to put on the multicart.

    Anyway, enjoy this video of the unboxing and printer self test.

    Cheers :)

    The Great SC-3000 Survivors Tape Restoration Project New Releases... 19 July 2015

    Two new releases for the tape restoration project today - The House and Help by Michael Howard.

    Sorry about the delay in releases - life is busy :) We have a couple more almost ready to go.

    ...see The House and Help tape releases for Sega SC-3000

    The Great SC-3000 Survivors Tape Restoration Project... 16 April 2015

    We've always had a long term plan to clean up and release the SC-3000 tape software into the wild. We've finally started. Well, slowly anyway :)

    We'll try to put out one or two remastered tape releases each month for the rest of 2015. These are 16-bit 44.1Khz WAV audio files, but are highly compressible because they have been digitally generated. They will work on original SC-3000 hardware and in emulators like MESS.

    Life is very busy, but now the pages are up and running hopefully we'll be able to keep the releases coming. Check out the Tape Restoration Project pages for the latest releases, and some articles on various ways of remastering SC-3000 tape software, plus anything interesting we want to record about particular tape loaders or tape copy protection etc. for future reference.

    Our first two releases are The Secret of Bastow Manor (text / graphic adventure) and Vortex Blaster, a vertical scrolling shoot-em-up and the first SC-3000 title to feature digitized speech.

    Look for some more next month.

    SC-3000 / SC-3000H Multicarts available again, plus some cool new labels... 5 Feb 2013

    Mk IIb Multicart PCB (Jan 2013)

    Hi All.

    Well, there was enough interest in the old girl to get another run of SC-3000 Multicart PCBs off the ground. The PCBs look good. We rebuilt the design in Eagle CAD to give us a bigger range of manufacturers, and the new Mk IIb PCBs now have a nice little SC-3000 Survivors logo on them :)

    We used PCB Wing (, and they have done a nice job. Their website is totally automated. Just get a quote for the board size and features you want, upload the gerber files, then once they pass DRC checks manufacturing is automatically scheduled. Very cool.

    We ordered a few spare PCBs, so let us know if you want to buy a SC-3000 Multicart.

    New black vinyl label for Multicart

    But that's not all. Each cart now comes with a nice vinyl label printed in stunning black.

    Oh yeah :)

    No more smudging, and no more Inkjet Hell.

    Roll of labels for Multicarts

    The new labels are removable, so you can lift them if you need to get access to the case screws. We just hope they have enough long term stickability. Only time will tell :)

    We would just like to say a big thanks to Labels Plus for doing a great job on these.

    Their website was excellent. It had an online quoting facility, and all the information we needed to create correctly formatted artwork suitable for printing. And the price was very reasonable too as they only have a $50 NZD + GST minimum charge. 128 labels cost $68.63 NZD including GST and courier charge. Christine at Labels Plus was a big help, and they sent us a couple of proofs for free before placing an order.

    Astro Dodge - New release for SC-3000 / SC-3000H / SG-1000... 8 Dec 2012

    Astrododge boxed release 2012

    Hi All

    We are very excited to announce that Revival Studios is now accepting orders for Astro Dodge. This great new cartridge game for the SC-3000 and SG-1000 is reminiscent of Space Slalom, but much more fun with reward pickups, head-to-head mode, and an Internet Hi-Score Hall of Fame where you can submit your best scores.

    Revival Studios is also releasing a cheaper version on tape for SC-3000 users.

    Disclaimer: We've been involved with the cartridge production and advice with porting to the SC-3000 and how to create a tape version of Astro Dodge. We don't get any kickbacks from the sale of this game, we just think it is really cool that Revival Studios have churned out a great new title for our favourite home computer :) So please head over to Revival Studios and check out Astro Dodge.

    The Great SC-3000 Cartridge Case Project... 7 Dec 2012

    blue and black cartridge cases (front)

    To cut a long story short, we can now make our own awesome SC-3000 Survivors Cartridge cases, and all Multicarts ship with a case! Check out how we did it in The Great SC-3000 Survivors Cartridge Case Project.

    Print your own Multicart Labels (updated)... 30 Mar 2012

    glossy photo paper vs crappy label paper

    Hi All

    Here is the SC-3000 Multicart Label sheet for you to print your own labels.

    I did my best to make some nice sticky labels to ship with the Multicarts. Unfortunately the label paper I used was very disappointing as it smudges easily, is thin, and has poor color balance.

    So my new recommended setup is to print the labels on to glossy photo paper designed for your printer and using original inks. That looks a lot better and it less likely to smudge.

    You can then use a glue stick to attach it to your cartridge shell. Cover the label with a tissue or clean piece of paper when you press it into place so you don't get your fingers all over it. And don't use too much glue as it may squidge around the edge of the label when you press it down.

    I'm much happier with that. The photo paper is a lot thicker, so it stays flat. And by using a glue stick you may even be able to lift the label later on if you need to unscrew the case.


    Multicart User Manual v1.01... 22 Mar 2012

    Hi All

    The SC-3000 Multicart User Manual v1.01 is now available for download.

    I've tried to summarize and include all the interesting or relevant information that is spread around the website or in the SMS Power Dev Forums into a single document. Most of you will only need the Quickstart Guide and Care of your Multicart sections. But there is also a History section, How it Works, Programming reference, a list of all software shipped with the cart as standard, and the Credits and Acknowledgements section. I may make a few more improvements, but this is getting close to the final version.

    I've just about cleared the backlog of orders. There are still a few PCBs left, so get in quick if you want one.

    Once again, many thanks to everyone who participated in this project. It has been around 20 months since we conceived the idea, and the last 6 months or so have been crazy busy. But I'm very pleased with how the Multicart has turned out. It does almost everything I had originally envisaged, and in some cases more besides.


    Inkjet Hell... 13 Mar 2012

    SC-3000 Survivors Multicart Label

    I'm working my way through the order list and the next 8 SC-3000 multicarts are ready to ship. Some of them have been ready since last week. But I've been trying to print out and include a nice sticky label with the carts for you to put on your donor cart cases. It even has a circle that shows you where to drill the hole for the reset button (thanks to Francesco for letting me borrow his artwork). Sounds simple right?

    Well... I'm just about to give up on that and send you all a pdf you can print out yourselves.

    My printer was out of ink. I don't keep the colors stocked up because the kids just waste them on pictures of Dora the Explorer. But I thought this was a good excuse to refill. So I bought a full set of 5 high capacity recycled / refilled carts and some glossy sticky labels. I ran a test sheet, guillotined them, and they looked good.

    Oh oh... those refilled ink carts smear, dammit. I figure I'll do a print sheet at work and check it isn't the label paper that is the problem. Sure enough, the one at work is colorfast and water resistant, although being an el cheapo printer it looks like crap.

    So I try the home printer again a day later. AAAAAGGGGHHH WTF WTF WTF???? Looks like the refilled ink has clogged the photo black and magenta nozzles, and the yellow and cyan are a bit iffy too. Lots of running cleaning routines but nothing.

    Ok - back to the store and swap for genuine HP cartridges (and pay the extra $60). Back home and... nozzles still clogged, possibly even worse than before because cartridges were out of print head all day.

    Hunt around on the net, find out how to pop the print head and give it a clean. It looks like that recycled photo black leaked ink all over the printhead. Great. Find some older sticky blobs of ink too and remove those. Get one on finger. About to flick into rubbish bin when HP printer decides to park the print carriage and it tries to snap off the open printhead release lever in the process. Rush to printer. Blob of ink falls into printer. Can't see where. Hope it doesn't cause a problem.

    Finish cleaning print head reassemble 3 times to get past HP warnings about printhead problem. Print test page. No improvement on clogged nozzles. But now I get a nice big black stripe down the page from that ink blob that fell onto the paper roller and is hiding in a place I can't remove it.

    So... cost of failed sticker experiment so far is approximately $170 USD, and that doesn't allow for the fact I may need to buy a new printer now too.

    Bugger :)

    Hopefully if I feed 100 or so sheets of blank paper through the printer then the black smear will disappear, and I may try soaking the printhead in distilled water for 24 hours to try to unclog the nozzles. But otherwise it is stuffed.

    Update: 14 March 2012

    I saw a cheap HP 3070A all-in-one printer on special for about $60 USD. It uses the same HP 564 inkjet carts as my old HP C6380, so I figured that was the best way to avoid totally losing the investment in new inkjet carts. However I hope they are still fresh when I get to use them. There should be a special circle of Hell reserved for whoever decided to chip the carts that come with a new printer so that the printer won't initialize using a standard set of carts.

    Anyway - the new HP 3070A works well, so you will all get a couple of sticky labels with your carts. The ink can still smudge a wee bit, so be careful when handling them. They work out to about $4 USD per label after this debacle :)


    SC-3000 Multicarts are shipping now... 2 Mar 2012

    Hi All. I shipped out the first two production multicarts on March 2. Thunderbirds are go!

    I'll start contacting people with paid up deposits as I work my way through the pre-order list. That could take 3-4 weeks for people near the end, so please be patient. Hopefully quicker than that though :) But feel free to email if you want an update on where you are in the list.

    Thanks once again to everyone who chipped in with a deposit to get this production run off the ground. There are still a few carts left, so get in quick if you want one. I suspect I'll be taking a break from this project for a while once I've shipped the last one :) It has been fun, but it has also been a huge amount of effort over the past couple of years, and the past 3-4 months especially.


    Deadly Jewel of Antark and Satellite Salvage... 27 Feb 2012

    Great news! We've just recently managed to dig up two tape classics that we hadn't seen in 25 years. Many thanks to Glen for spending a couple of days digging through his cupboards.

    The Deadly Jewel of Antark is an early RPG by Grant Emms who later wrote Delta Fighter and The Tomb of Nozar.

    Satellite Salvage is a fast machine code game by Shayne Burbery. Use your jetpack to pick up the falling pieces of satellite and return them to base whilst dodging the aliens. The aliens get faster and more appear as you go up the levels. Fast and addictive.

    Check out the following video for a glimpse of DJOA, Satellite Salvage, plus some of the many tape games from Sega Magazine like Colditz, a Basic graphics demo, the new Text Adventure menu, and a quick look at a funky little Pacman clone called Demon Gobbler.

    The lighting isn't the best, and the iPhone struggled with the colors on screen a bit, but you should get the idea :)

    Deadly Jewel of Antark and Satellite Salvage just arrived over the past weekend, so I'm going to miss that 1 March shipping date by a couple of days. But nearly there.

    Added 40 more tapes to SC-3000 Multicart (now 70+ tapes)... 21 Feb 2012

    Hi All. We're making good progress and it looks like we should hit that 1 March shipping date for the first paid up multicart.

    The multicart software is almost finalized now. Here are the most recent changes:

    Commercial SC-3000 Games

    Educational / Utility SC-3000 Tapes

    Sega Magazine Software

    Check out the full list of over 30 SC-3000 tape games

    The SC-3000 Multicart PCBs have arrived... 9 Feb 2012

    Mk IIa SC-3000 Survivors Multicart

    Good news - the new SC-3000 Multicart PCBs are here! I assembled one last night to check and it works fine. Futurlec have done a nice job again. Observant viewers might notice a couple of minor changes from the original Mk II layout.

    So it is a good time to update everyone on progress and when you are likely to get your multicart.

    I need until around the end of February to finish tweaking the Multicart software. Actually, I could happily spend another 3 months tweaking it, but I need to make a cut somewhere for your sanity and mine :) So I will make up a final to-do list which is achievable, then I'll try to stick to that and 1 March 2012 for shipping the first multicart.

    After that I will work my way through the list of orders as quickly as possible. But I can really only build one or two of these carts a night at best, and that's only if the kids go to bed nicely :) So please be patient, and feel free to contact us if you have any questions.

    Mk IIa SC-3000 Survivors Multicart PCBs in their packing from Futurlec

    Off the top of my head, the to-do list is approximately

    Hmmm... that seems like a lot to get through in 3 weeks, so I may have to skip some of that in order to make the cut.

    I want to do the following too, but these will probably miss out:

    Once again, many thanks to everyone who stumped up with their deposit to make the production run possible. I finally shipped some of the prototypes to the other Survivors for testing last week and they were blown away. So I hopefully the end result makes all the waiting worthwhile :)


    Lots more SC-3000 tape software goodness... 1 Feb 2012

    Hi All. Just a quick note to let you know we've added a pile another 13 interesting items of Sega SC-3000 tape software to the cart.

    The demos are original Sega or Grandstand demos that show off the flexibilty and power of Sega Basic very nicely.

    Check out the full list of over 30 SC-3000 tape games

    Sega Music Editor Demo Tunes on Multicart... 8 Jan 2012

    Hi All - Happy New Year!

    Sorry it is has been a while since the last update - real life intruding and all that :) But the family had a nice Xmas despite all the rain. We're currently trying to confirm the Multicart PCB order with Futurlec, and we'll let you know when that is officially underway.

    Anyway - back to the update. Here's a new video clip for you:

    I tidied up a couple of little things, and added something very cool.

    The first tidy-up is a menu option to let you toggle the Print64 Menu System on and off. So you get the small text by default, but if you find it just too damn small you can still quickly switch to a text mode menu instead.

    Second, I tidied up the EPSGMOD Player code. I got rid of a couple of glitches, added a simple title screen, and compressed 8 EPSGMOD / VGM music files into a single 32KB block. They sound great, and now it looks nice too.

    Music Cart Demo Cassette (image courtesy SC-3000 Survivors)

    Music Cartridge Demonstration Cassette

    The cool new thing is the demo songs for the Sega SC-3000 Music Editor.

    You've probably seen the Music Editor before, but never really played with it. That's not surprising as you really need the keyboard overlay and a bit of patience to learn it. And a bit of musical talent helps too :)

    The Music Editor is actually a very capable little cart that lets you compose songs using one of three instruments (Piano I, Piano II, Organ) and 3 note chords. You can then save / load these tunes to tape or even print them out if you have a printer / plotter.

    Sega / Grandstand Leisure Ltd released a demo tape that you could buy with 10 demo tunes on it to showcase the cart's capabilities. And now the Multicart has those included too. There is just enough empty space in the Music Editor ROM to embed a compressed copy of the tunes and self extract them when the cart loads. They are a really nice collection of classical tunes:

    Music Cart Demo Cassette Inlay (image courtesy SC-3000 Survivors)

    And remember, we are currently organising our production run, so please order your multicart now.

    Xevious on the Sega SC-3000... 14 Dec 2011

    SMSPower recently released a dump of Xevious for the Korean Gamboy / Master System clone. I was very excited about that because I loved the arcade game. And even better, because this was an MSX port running in legacy mode it should work on the SC-3000!

    Most of the Korean / Taiwanese dumps I've tried have two problems on the SC-3000. First, they don't initialize the SC-3000's PPI so the joysticks don't work. No problem - the multicart menu system does that automatically. Second, they often have conversion errors with bad memory addresses that rely on RAM mirroring to work. No problem - the multicart now has jumpers to disable the SRAM on the cart.

    So I fired it up and... nothing. Ok - it looks like this game needs more than 2KB of RAM (confirmed in MEKA debugger - it requires 8KB of RAM from E000 to FFFF and there are no read / writes from $8000 to $DFFF). So I switch the jumpers around to use 32KB of RAM and WOW that's some funky screen distortion :)

    After a lot of playing around in the MEKA and BlueMSX debuggers I found the two problems. It all has to do with the differences between the SMS VDP registers and a real TMS9929A.

    TMS9929A register 1, bit 7 and 4K VRAM

    The first problem is the way the code tries to turn the screen update on / off when updating the VRAM tile set etc. It writes $42 to VDP register 1 to disable interrupts and $62 to register 1 to enable interrupts. That works out like this:

    The problem is that bit 7. It is ignored on an SMS, but on a real TMS9929A it forces the chip to use 4K of VRAM instead of 16K of VRAM which does some interesting things to the tile sets :) I think that's because the original TMS99xx chips only had graphics mode 1 and 4K of VRAM. The TMS99xxA adds extra modes, but still gives you the option of running with only 4K of VRAM.

    So the solution is to change the code to write $C2 and $E2 instead of $42 and $62.

    VRAM update code writes bad value to VDP register 6 which shifts Sprite Generator Table

    The second problem is that for some bizarre reason a couple of the VRAM update routines that are called later on have a hard coded write of $00 to VDP register $0E. This is ignored by the SMS VDP, but the TMS9929A treats it as a write of $00 to register 6 which resets the Sprite Generator table position from $3800 down to $0000. ie. it overlaps with the tiles, which is why you get to fly a bunch of letters around the screen :) Since the SMS ignored those instructions anyway, we just nop them out.

    If you want to see the way it looks on a real SC-3000 with 32KB of RAM on the cart, use BlueMSX and set up the memory space to 32KB RAM from $8000 to $FFFF. Or just check out the YouTube vid above. Enjoy :)

    WLA DX code to patch the Xevious ROM

    Here's a WLA DX .asm file that shows how to patch the Xevious ROM to work on an SC-3000 or SG-1000. Note that the cart you use will still have to have 8KB of RAM or more and it must be available from $E000 to $FFFF. Or you could just order one of the multicarts ;)

    PCB Jumper Mods - likely production layout... 11 Dec 2011

    Extra Jumpers. J2 (bottom of picture) disables cart SRAM. Remove J3 (right of picture) if you are using an EEPROM / Flash chip

    Hi All. I tried out a couple of changes to the PCB over the weekend. I drilled some extra holes in the PCB, cut a few traces, and added some extra jumper wires to the back. This is very close to the layout I will use for the production PCBs (without the jumper wires, of course).

    I think I will probably start to confirm orders and collect deposits soon so I can order the PCBs. They will probably take 6-8 weeks to arrive because of Christmas, so that should give me plenty of time to finish off the cart software.

    I'm actually really busy at work and home at the moment, so it may be another week or so before I start to contact everyone who has expressed an interest about that.

    J2 - Disable SRAM

    I had always intended to let you use the SC-3000's onboard 2KB of SRAM by removing J1 (top left in photo). Unfortunately I forgot to disable the SRAM on the cart, so that didn't work. Oops. Now you can remove J1 and shift J2 from pins 2-3 to pins 1-2. J1 enables the SC-3000's onboard 2KB of SRAM and J2 disables the SRAM on the cart.

    Underside of PCB. Extra jumper wires and some PCB traces cut.

    This is important for the Korean / Taiwanese MSX to SG-1000 / Gam*Boy ports. Unfortunately most of those have errors where they didn't correctly remap all the memory locations to the $C000 to $C7FF range. That is fine if you are using the SC-3000's onboard SRAM because the memory space is mirrored, so if you accidentally read / write to a higher location it still works. But that fails when you have 32KB of RAM. I will try to provide patches for those ROM images, but in general if an SG-1000 ROM game doesn't work on the multi-cart, then try disabling the cart SRAM and it should work.

    The other problem with those Korean / Taiwanese ROMs is that don't initialize the SC-3000 to turn on the joysticks. So the multicart menu system does that automatically for you before the ROM image is launched.

    Pin 31 / A18 on the AMD29F040B EEPROM force high. Slots 0..7 and 8..15 are the same and slots 16..23 and 24..31 are the same.

    J3 - Flash/EEPROM Jumper

    Charles MacDonald suggested in the SMS Dev Forums that I support EEPROMs as well as EPROMs. The multicart actually does that without any jumper support, but J3 makes things a bit tidier. When you remove J3, then pin 31 on ROM 1 (the left hand ROM) is tied to +5v. That disables the write circuitry in the Flash EEPROM chips.

    It also has the effect that slots 0..7 and 8..15 are the same and slots 16..23 and 24..31 are the same. So I'll tweak the auto-scan routines to look for duplicates and only show 16 slots instead of 32 when using a Flash chip.

    Note: J3 only controls ROM1. ROM2 always has pin 31 controlled from the '373 latch. Basically this was a trade off between giving you guys a bit of extra flexibility, and keeping the Jumpers easy to use. I could have controlled each ROM with its own jumper, plus shifted corrected the A18 control line from the latch across to pin 1 on the ROMs, but I would have needed another 5 jumpers to do it. That would have been hard to fit in, and very easy to stuff up the jumper settings - hence the decision to use a single jumper.

    Mike Hadrup's Print 64 routines in Boot Menu... 5 Dec 2011

    Hi All. The Geek Factor is pretty high on this post, but I've been wanting to try it for years and it covers an interesting piece of SC-3000 history.

    Mike Hadrup was the last editor of Sega Computer Magazine in New Zealand from 1987 to 1988. He was only 18 at the time, but he wrote a lot of really cool toolkit to extend the Basic Interpreter for the SC-3000. One of these utilities was Print 64 (published in Sega Computer Magazine October 1987).

    Original Boot Menu, text mode. Note how some tape names are too long to fit

    The SC-3000 uses a TMS9929A or TMS9918A video chip. In text mode you can display up to 40 characters across and 24 rows down, but you are limited to two colors and no sprites. This is good, but it looks a bit boring and you can't fit much text on the Multicart Boot Menu. In particular, it means that if I want two columns in the menus then I have to use short names for some games.

    The Screen 2 graphics mode gives you 256 x 192 pixels with 16 colors and sprites (this is what the games use). So I can make the boot menu look better, but you can fit even less text in - only 32 columns by 24 rows.

    That is where Print 64 comes in. It works in Screen 2 graphics mode, but it paints two characters into each 8 x 8 pixel block on the screen. The characters are only 3 pixels wide each (with the 4th pixel column being whitespace). So the text is a lot smaller, but it is still looks really good on a CRT - the screenshots don't quite do it justice. Check out the video for a better idea of how this looks on the Multicart.

    Boot Menu using Print 64. The characters are small but legible and you can fit lots more in.

    Print 64 has a simple window system (you specify top left / bottom right of window) and the routines take care of all the text wrapping / scrolling etc. inside that window whilst leaving the rest of the screen intact. Most of the standard layout commands are in there - CR, LF, CLS, simple tabbing system, inverse characters etc.

    Mike also provided a hook into the Basic IIIB Print command. So all you had to do was to add the machine code to your program, activate the hook, POKE the window bounds and cursor position into RAM, then execute Basic PRINT commands to output 64 column text to the graphics screen.

    This made it really easy to extend your own programs. Unfortunately, interest in the SC-3000 was dying out by this stage, and Mike was moving onto bigger and better things at University so we never really saw much software that took advantage of his toolkit. But it is seriously cool and is definitely worth a look.

    Boot Menu using Print 64 plus SC-3000 Survivors Logo. This is the other cool bit of Print 64 - because it uses the graphics screen it is easy to mix extra graphics in.

    The good news is that Print 64 is actually quite portable and is (almost) totally independent of the IIIB ROM. I've disassembled and commented a fair chunk of it, and eventually I plan to post a WLA-DX .asm so you can include it in your own projects if you're interested. It should work fine on an SMS in legacy Screen 2 mode as well as MSX machines with a bit of tweaking - perfect for text adventures or word processors :)

    So... am I going to use Print 64 for the Boot Menu? I'm not sure yet :) It is very cool code, and a fitting piece of SC-3000 History to include in the Multicart. But... that text really is pretty small and it is harder to read than the normal sized text. I'll have a play around with it and make my mind up. But I think the Geek Factor alone may mean I stick with Print 64 :) To be honest, my head says to use the standard graphics mode with a single menu column and standard sized text, but my heart says Print 64. We'll see.

    Video showing the difference between Print 64 and normal text mode on a TV screen

    4 New Tape Games Added... 19 Nov 2011

    My replacement Top853 Programmer arrived nice and quick - $45.59 USD including shipping. Thank goodness for eBay, cheap Chinese production, and free shipping! It only took about 10 days to get here from China.

    I think the trouble I had with those AMD29F040B Flash chips was just coincidence as they work fine with the new programmer. They erase, write, and verify perfectly now. In retrospect, the old one was always a bit twitchy. The chips seem to work fine on the Mk II Multicart, so I may support that as an option in the future.

    Anyway, I'm pleased to announce that the MkII Multicart now has 4 new tape games:

    My Programmer Died, so check out some vids... 11 Nov 2011

    It looks like my Top853 Programmer is malfunctioning. I bought some cheap AMD29F040B Flash chips off eBay, and the problems started after that. Now the programmer won't work with the 27C801 EPROMs I've been using either. I keep getting write errors, and I can't get a consistent read off a known good EPROM either. Probably coincidence, but I'll dump that batch of Flash chips just in case.

    So while I'm waiting for a new Top853 Programmer to arrive in the post I've made two more videos. The first one shows you some of the Multicart software features I've been working on over the past couple of months, and the second one shows you Burglar Bill, a 1980s class from Mike Boyd.

    Enjoy, and you can also find all these videos on the SC-3000 Survivors YouTube Channel

    As you can see, the multicart content is coming along nicely. Here are the main features in the Video:

    Burglar Bill

    Burglar Bill is a classic 1980s JetSet Willy style level based game from Mike Boyd. Here's the quote from the cassette inlay:

    While doing the rounds of the local village one dark night, Bill comes across a large dark mansion situated on top of a small hill. Seeing no lights on, Bill decides to check the place over. Inside, Bill comes across a large wooden door. Opening the door, Bill makes his way down into the darkness below...

    Your Job: Guide Burglar Bill through the many cellars of the mysterious mansion, collecting the treasures scattered through them. But beware! Each room is guarded by deformed creatures under the control of their creator, the mansion's owner. Also, poison tipped objects litter the cellars making your passage through them very dangerous. After collecting the five objects from each room, a door allows access to the next of the ten rooms, with a new challenge in store for you.

    ...and here's the cassette inlay

    Update: 7 Oct 2011

    Welcome to everyone from SMSPower. We've come a long way since we put these pages together back in March. The SC-3000 Survivors MK II Multicart is now up and running. It has a Boot Menu, and holds up to 63 SC-3000 or SG-1000 games carts, or 30-50 games carts plus a pile of Tape Games which have been specially converted to load off the Multicart.

    Enjoy, build your own 32-n-1 multicart, and check out for more SC-3000 related goodness.