New Interface 2 games

[jimmy]

I've been away for a while (lack of time!) and have been trying to do some 8-bit development again. I have one of Fruitcake's excellent ZXC4 cartridges and rather than just upload SNA files into it I wondered how hard it would be to create a new Interface II ROM.

Some of the 16K games are easy to convert as they're small and don't use the ZX ROM. Others make extensive calls into the ZX ROM and these are the ones I've tried to convert.

I now have "Horace Goes Skiing" and "Jungle Trouble" working from ROM, but there appears to be no way I can upload the 16K image files to this forum? I would offer them to Fruitcake, but his website has gone offline (shame). I don't have a website to host them on, and the free sharing sites don't last that long before the link goes bad. Can anybody help?

[1024MAK]

The Fruitcake site is down due to a problem, more information here.

You could try git hub, or use Dropbox, Google Drive or other similar services.

Mark

[jimmy]

Thanks for the link 1024MAK - let's hope the website comes back online.
Paul (Fruitcake) if you're reading this then please PM me.
I did do a modified Deathchase game cartridge for the 30th Spectrum anniversary years ago, but WoS wouldn't/couldn't host it as the game was considered a 'mod'.
Other games I have made into ROM include Aquaplane, Blade Alley and Sir Lancelot.

[SamC]

Please, any news about modded ("ROMized") games?

[1024MAK]

Just in case anyone does not know, the Fruitcake web site has come back on line (some time ago now).

Mark

[SamC]

In addition to the above mentioned old games,
here are rom-versions of brand new games:

Coloristic - http://d.borik.net/speccy/sindikat_coloristic.zip
Mag the Magician - https://www.bytemaniacos.com/?page_id=3453
Dead Space - http://www.bytemaniacos.com/?page_id=3437

[Quazar]

Interesting to see new games and old games being patched to be ROMs.

I became interested in the ZX ROM cartridges last year and released an interface to allow them to work on the SAM Coupe (ZX-ECUTOR) in December. In April I released a 16 bank flash memory cartridge which will hold sixteen 16K images, with Radastan's games 'Mag the Magician' and 'Dead Space' pre-loaded with his permission. In May followed it up with a zx rom slot interface for the ZX Spectrum - for all models: 16k/48k/+/+2/+2A/+2B/+3 and also works on the Next.



Info -> www.samcoupe.com

[jimmy]

Paul (Fruitcake) has kindly uploaded the first 20 games onto his website - see http://www.fruitcake.plus.com/Sinclair/ ... rsions.htm

They are all 16K ROM images - no fancy paging routines required. Some of them run on 16K Spectrums too. Many of them are enhanced - simple things like supporting joysticks, or to fix annoying bugs (such as doing an "IN 0"), or even to support a different language.

Some of them use ZX7 compression - I try to leave a clue in the ROM that is being used, but sometimes there is no free space available. So I'd like to say thank you to the authors and hope they feel good knowing that their code is being used elsewhere!

I am currently investigating the use of Currah microspeech from 16K cartridges - but this is really hard because the built-in Currah ROM is paged in every IM1 interrupt and assumes system variables like RAMTOP and keyboard scan values are there.

Enjoy!

[Quazar]

That's some brilliant work Jimmy!

Just been trying a couple of them out on my flash cartridge with ZX-ECUTOR on the SAM Coupé. Horace, Trashman, Stop the Express and Pinball working brilliantly.

Only odd ones on the SAM I've found so far is Zolyx, where the cursor just moves to the bottom of the screen on the menu. And Sir Lancelot moving by itself. Are these games always polling perhaps for Kempston or other I/O based joysticks?

Edit.. yes, it's the automatic joystick detecting and setting which doesn't work due to the bus level when no device present on the specific I/O ports.

POKEs to the Sir Lancelot ROM to patch out the joystick detection setting so it works on the SAM Coupe via ZX-ECUTOR:
change the following bytes in the .ROM file: Address 208: 0,0,0,0

And for Zolyx, to remove kempston detection so it works on the SAM Coupe via ZX-ECUTOR:
change the following bytes in the .ROM file: Address 15890: 175,50,11,177,201

[jimmy]

More games have been delivered to Paul (Fruitcake) and should be online at some point. The list is :

• Tetris (managed to squeeze both 48 and 128 versions into one image, I guess a SAM will select 48 mode)
• Vectorball (fix the Fuller joystick routine so it actually works)
• Espionage Island (will now run on a 16K Spectrum - unlike the original)
• Kane
• Lap Of The Gods
• 3D Tank Duel (including fixes for the ZX Printer routines)

I've also just seen the ZX0 compression thread, and initial testing with it shows some promising results. Some games that I couldn't fit in now will. Highway Encounter will be the first cartridge to use ZX0.

I'm happy to address some of the issues when running it on a SAM, but I don't have one and I don't know how good the emulators are. For example, what does IN 31 or IN 127 return on a real SAM? And is it a stable value or does it float?.

[Einar Saukas]

I've also just seen the ZX0 compression thread, and initial testing with it shows some promising results. Some games that I couldn't fit in now will. Highway Encounter will be the first cartridge to use ZX0.

Cool

[Quazar]

Brilliant, looking forward to seeing these and more with the new compression.

Checking on a real SAM (as the true bus behaviour doesn't seem to be emulated from running the same tests on an emulator) the bus isn't stable when reading in from an unused I/O port (such as 31 or 127 as you asked).

The data bus at the Z80 side is pulled high, but there are two possible scenarios depending on what else the machine is doing:

- if the unused I/O port is read at the exact same clock cycle that the RAM is being read for the video display generation it'll return that byte value.
- else it'll return 255

[Quazar]

I saw 9 more of your patched games went live on Paul's Fruitcake site. Nice work.

Just popped them on my Flash cartridge, all work fine both on ZX Spectrum with my Interface 2 compatible ROM Slot Interface and my 16 bank flash cartridge. Also all working without issues on the SAM Coupe via my ZX-ECUTOR interface and flash cartridge.

Rasterscan is certainly an odd game, I do remember borrowing the cassette of that back in the day, but not getting very far in it. Not looked at the memory, but that ZX0 compression must be doing wonders - I should check the memory just to see how much RAM it uses when decompressed.

Tetris - saw an odd bit of code in that, where it accesses port 159 then clears 8192 bytes - clearing the multiface RAM to stop hacker toolkits? (that's just a guess - not searched to see what bits and pieces used that port number yet). Only reason it flagged up, as I have a run from RAM option with ZX-ECUTOR on the SAM Coupe, where it copies the cartridge into RAM to run slower*, but I do set the write protect option on the 0-16383 RAM page, otherwise that piece of code would have erased half of the cartridge image.

(*SAM runs at 6MHz uncontended speed from the ROM area, so all the original cartridge games can run too fast, so the run from RAM option copies the cart to RAM so it runs at a contended ~3.8MHz speed to be closer to the ZX Spectrum. (The ZX graphics MODE adds further slowdown, as normally with contention RAM speed is effectively ~4.8MHz)

[jimmy]

Another 9 games have been delivered to Paul (Fruitcake) and should be online at some point. The list is:

• Benny Hill's Madcap Chase
• Deflektor
• Flight Simulation
• Rupert and the Ice Castle
• Sooty and Sweep
• iD
• Play Your Cards Right
• Automania
• The Snowman

Sooty and Sweep currently holds the record as the biggest released game I've converted to IF2 cartridge - the code was originally 40085 bytes long! It's a shame that some other (smaller) games don't compress nearly as well.
I have one game that "Shrinkler" compression can make it fit into 16K, but ZX0 can't. I haven't released it yet as it takes around 75 seconds for the game to decompress before playing If I could squeeze another 100 bytes then a faster ZX0 version should be possible.

[jimmy]

A few more games have been added to the list, which will appear on the site shortly - they are:

• Revolution
• Draughts Genius
• FA Cup 87
• Evening Star
• Ski Star 2000
• Cyclone
• Rebel

Cyclone has beaten the code length record, it was originally 42240 bytes long! (starts from printer buffer and goes to $FFFF)

[Hedge1970]

Thank you for doing all this work, a nice option for using those IF2/Ram Turbo expansions. I’ve always liked Pauls dedication to these old 8bits.

[Luzie]

As can be read here: https://worldofspectrum.org/forums/disc ... ent_935641
I ´ve done two more in 2018:

I´ve done another IF2-ROM with Jimmy´s utility ( https://www.worldofspectrum.org/forums/ ... ent_263330 ) :

Cyber Rats (Silversoft Ltd, 1982, Arcade): (CYBERRAT.ROM): Download from here: http://forum.tlienhard.com/phpBB3/downl ... hp?id=7526

IF 2-ROMs like this can be easily tested with SpecEmu Emulator (File / Load Interface 2 Rom...)

More 16k programs wait for trying to convert them to Interface 2-ROMs ... http://www.tzxvault.org/16k.htm

Arcadia (Imagine Software Ltd, 1982, Arcade): (ARCADIA.ROM): Download from here: http://forum.tlienhard.com/phpBB3/downl ... hp?id=7525

[jimmy]

As can be read here: https://worldofspectrum.org/forums/disc ... ent_935641
I ´ve done two more in 2018:

That explains why I saw those 2 games for sale on Etsy!
This was brought to my attention recently, as some of the images I've created are also for sale. For the record I wasn't asked about this and it has nothing to do with me. Personally I'd advise people to purchase a programmable cartridge like Fruitcake's amazing ZXC4 cartridge. I'm intending to fill one of these up, but 4Mb holds a lot of images!

If anybody has a request to see a particular title then please PM me.

Most of the 16K games are not worth my time converting - I still have a few more to do but as they contain BASIC they require more effort to convert. I have a pile of games "in limbo" where I've started to convert them and got stuck. Some are still slightly too big, others require more major code changes - Chuckie Egg I'm looking at you! (It can't support Interface 2 joysticks as is)

A lot of the good 48K games are too big even with the amazing ZX0 compression If only I/F2 cartridges could support 32K ROM - then pretty much every 48K game could be converted.

[jimmy]

Some more games have been added to the list recently, they are:

• Survival
• Manic Miner
• Jonah Barrington's Squash
• Xeno

The Manic Miner cartridge was intended to be my Spectrum 40th anniversary contribution, but better late than never!
The last two required some persuading to fit into 16K - Squash is basically a lot of sound samples and Xeno is a massive bitmap.

[jimmy]

With the recent passing of John Gibson, I thought I'd try and convert his games to cartridge format (well at least his earlier Imagine games as they have to fit into 16K...)

I've completed the first three, so the following games will soon appear on the website:

• Molar Maul
• Zzoom
• Stonkers

Stonkers took a lot of persuading to fit inside 16K -there is only 1 byte to spare and that's not usable due to the position of the Z80 IM1 and NMI routines! I haven't implemented any bugfixes, so it will probably crash in the same way as the original. Did anybody release bugfixes for this game?

In addition to updating the Zolyx image to stop any cheating(!), there are two new images:

• Master Of Magic
• Jet Set Willy

JSW was another tight squeeze - requiring double ZX0 compression. It is similar in style to the Manic Miner cartridge, so includes some POKE options and a turbo mode.

[Quazar]

Looks like you've been busy with more releases - catching up with the ones I've missed, the four from June last year with Manic Miner all work on the SAM via my ZX-ECUTOR interface. The POKE menu with MM is a very nice addition, excellent work!

Looking forward to trying JSW when the latest batch are available.