One clarification: At around 15:00 I simplify things quite a bit by saying the address bus determines who that data is intended for. I left out the part that in the case of a Z80 like we have here, there are also control signals that come into play (/MEMRQ and /IORQ) that determine if the data is intended for the RAM or another chip. There are other architectures that have memory-mapped I/O where the control signals aren't necessary and a specific address is all is needed to target a particular chip.
Ah yes, I was a little confused when you were explaining that since I'm familiar with the Z80 architecture and I/O is treated very differently, not occupying memory address space. Not really a consideration when trying to explain it I know.
I can still read you address on the package that was mail to you... you HAVE TO do better than that if you want your address to stay private.... maybe a few extra layers from the marker next time? - just thought I'd let u know :)
I had the Schneider CPC-464 (German version) and a flight simulation game simulating an Apache Tomcat helicopter. It had a copy protection - it displayed a pixel pile and one had to use a foldable plastic lens positioned at some marks to read a code that was hidden in the garbled pixels. No matter how I tried, I got the digits wrong in 8 out of 10 cases. That's why I bought the Multiface II - once I had over one the code deciphering hurdle successfully, I saved the game right there, and from then on I was able to fire up the game and play without that endless annoyance. These were the times ...
That was the only CPC game I never managed to convert to disk. The loader copied itself down to memory location 0 then decrypted itself (I got bored after working through 7 or 8 layers)
I believe the most underrated part is the explanation of how the data/address bus work! I will be constantly referring this to people who want a simple and straight forward explanation about that subject. It was brilliant!
A college friend of mine and a partner designed a board, which did exactly the same thing for the Apple II, which would have been around 1979-80 from memory. They set up a company and sold huge numbers, mostly in the USA and for a few years it made quite a lot of money. There were attempts by software companies to stop the sale of these type of devices, as they were widely used to bypass copy protection, but they all failed as (officially at least), they were sold as ways of making legitimate backups of software. So, these sort of boards were around for some years earlier, albeit for different machines.
I have a similar story. I had the Commodore 64 and did exactly the same thing as you, reverse-engineering the code to add infinite lives and stuff like that. I also converted a lot of cassette games to load from the disk drive, adding a small turbo loader to speed things up a bit. This taught me so much about 6502 assembly and also about the Commodore 64 and Disk Drive hardware and memory mapping as well. Good times, I remember them with fondness. By the way this multiface is very similar to the Action Replay and Final Cartridge versions that we had for the Commodore 64. Great Video ;)
@@NoelsRetroLab That is the downside to a mature market. Now th sbc:s and microcontroller dev boards fill that function and maybe to some extent android devices.
Noel. You are a true genius in everything you do and how you explain it brilliantly. I have no background in electronics except what I learned myself over the years. My background is industrial automation making today's industrial world more efficient but my love is old stuff. So we'll designed and thought out with what they had. I have bought and repaired vintage amplifiers, twin cassette decks that I now listen to. Long story short I bought 4 items on ebay untested of course. 2 Atari's 2600, both fixed. A commodore 64 PSU issue so today I rebuild a new PSU by hammer and punch literally breaking open a brick of death to get the 9 volt ac transformer and rigged a 5 volt switching charger to the din power plug for the 64 and working perfectly. My problem is my last one an Amstrad cpc 464. Anytime I power it on I get zig zag, horizontal lines but most frequently white screen black border. I have schematics but I work with a magnifying glass a digital multimeter and a hunger to know why and what am I missing. Any ideas and how did you learn all this? Life I know but books, college etc I would be extremely grateful for any information. Best on TH-cam without a shadow of a doubt. Keep posting.
This is the first thing I ever saved up for. 4-5 weeks doing two paper rounds. It was brilliant (I sold a whole load of CPC stuff 4 years ago when I moved.... There were three of them in the box!)
I remember cracking "Highway Encounter" to be able to save to diskette and not needing the tape to load it. I found a hidden message from the author (Mark Haigh Hutchinson). I wrote him a letter to the given address (because the message said so) and he even sent me a letter back. I believe he has passed away unfortunately. I actually made a turbo diskette loader with only one big sector per track which loaded it very fast. And the icing on the cake was, that the loader was started with the |cpm command. This was great fun for a 16 year old😊
I hadn't seen anybody using a rag over the board when you are using IPA, to clean the flux and then using the tooth brush over it. I was always having problems to clean the flux and your method seems to work perfectly well.
Nice clean build and some great technical information shared there, Noel. Skills acknowledged. Glad you finally got your Multiface II! I had an Action Replay on my Amiga and loved it. Had no clue what this was in my Amstrad days but it would have been a hoot.
Excellent explanation of how the device works. Great video! Your proposed new device would be very useful for those with busy lives, allowing them to stop and restart their gaming with little lost time.
That little note "the Multiface II+ must be present, so pirates will find this about as much use as a rubber cutlass." Sure, unless everyone has one. I can imagine this was great for kids who only got to play a limited time from their parents, meaning they could actually play the whole game instead of just repeat the first levels.
I remember a friend of mine back in the day had the MF and was using it mostly for copying games, and what a coinsidence to pause HOH, like in this video. I remember begging him for several days to borrow the device for testing, which I got, only to discover that in real world senariors most users wouldn't bother that much about the "pause and save state" memory dump feature but rather for the other major benefit of removing copy protection and transfering software from tapes to disk which did require specific skills that n00bs didn't have. Most of them just wanted to copy and trade games with each other. That was actually my first "gig" in the IT sector back in the '80s as a teenager and let me tell ya, making the equivalent of an adult's salary with minimal effort, was an incredible thing. I was already writing code and even made 3 game clones (pacman, donkey kong, snake) and also messed around with a type of quasi-hardware sprites that were theoretically impossible on the CPC, but it was that period that I got my first serious experience of learning both about hardware and software (albeit I started with a C64 before the Amstrad CPC). Although "technically" illegal in today's terms, it gave me a glimpse of how much money could be made in the computer sector, and after that I never looked back. Over the years I got degrees in programming and design and had multiple careers as IT technician, CG artist, web developer and even got some inventions. Now as far as the Multiface goes, because Discology and Pyradev were able to do the "other half" of MF's major features and there was no need for extra hardware, MF was not as popular as most people think. In fact its because of those abilities especially in Discology, that it became THE software to own for the CPC. I almost made a living because of that thing for several months at the age of 14, providing "reverse backup services" *wink wink* to people that had tons of software on tapes, and paid good money to transfer them to floppy disks. In "partnership" with 2 local computer stores I made the equivalent of 200 euros per week (in todays money adjusted for inflation -- that's a full time salary) and for a teenager of the '80s such easy cash made me feel like I've cleaned up a Casino or something. LOL! So thank you Noel for brining back those "memories" - no pun intended ;-)
Some additional details. The filtering of the I / O addresses of multiface 2 is much more precise than that of the circuits. Thus, only bit 14 of the address (= 0) is enough to access the CRTC, whatever the value of the other bits 10111100xxxxxxxx = BCxx. Bits 10, 11, 12, 13 and 15, when set to 0, allow access to the other circuits. (Say otherwise it's possible to address several circuits simultaneously) So instead of using BC to access the CRTC, you can also use 00111100 = 3C. One of the many ways to crash a program saved by the multiface is to set all the CRTC registers to 0 on the BC port, and set the normal values with 3C. So when the multiface wants to reset the values to their correct values, it crashes the machine. It is much simpler than trying to detect the card. I no longer remember if the interface correctly manages the return address from the interrupt when Z80A Stack Pointer register is located between 0000 and 3FFF when the button is pressed. It would be also interesting to know how the multiface detects what is the interruption mode of the Z80A when the button is pressed.
Thanks for the details. I didn't know that. I did read that the Multiface fails to return correctly when the stack is located in that area, so that probably confirms your suspicion.
@@NoelsRetroLab You're welcome. The interface is also capable of saving the additional 64k if it has been used by the program. And there is also a software capable of reloading these files without the interface connected. ;-)
You might describe the technique whereby I/O write data is stored on the Multiface II as "bus snooping". That's a term normally applied to caches, but I think it could apply here as well.
Amazing video. I was cracki g games for the c64 back in the day, but I used an action replay mk5 to be able to debug the code and remove copy protection. This did not stop me from learning, because saving a freeze file was considered lame. So the main use for the action replay in this regard was to set a breakpoint on the loading routine, so that we could save the memory before a game would start. Porting multi level cassette games to disk by saving each chunk of level data and by rewriting the loading routines in the main game was fun too. 😁
I used to borrow my friends Muliface 128 for the Speccy in the 80's so I could transfer my games to Microdrives. Last year I found that a Muliface 128 clone had been made. (Probebly the same people that made yours). So now I have my own. Yipee. :)
I used to have an Action Replay, a similar device for the C64. Great little piece of hardware. I used to use it to copy my own tape games to other tapes, I didn't own a disk drive, as the turbo tape loader was much faster. You could get a game that would take around 100 on the tape counter down to 60 or even less in some cases. On a C60 you could get 5 or 6 games per side, if I remember rightly, and I'd put my original copies away and just use the fast loader. Since you could save where you like, you could just bypass any code style copy protection with ease. The big issue is that it didn't work on multiload games, for obvious reasons.
Most likely two transistors in case you don’t read the instructions about the mistake and put it in the wrong way around. So in the case you can cut the old one out, which is a lot easier than de-soldering if you don’t have the correct tools.
This is amazing! Thank you so much! I came here, because I found out that WinAPE allows to attach a Multiface II ROM. Now I know how it feels like, because I never had one. And naturally many ideas come up: Is it possible to dump my favorite game at a certain level and then transfer it to my real 464? Yes, but you need something like Anti-Multiface which allows to restore a backup without a Multiface present, but Anti-Multiface requires 128kB, but then I found MF2RR which works with 64kB! Hilarious! I tested it successfully!
I wanted one for my CPC 464+ SO BAD back in the day! The closest I ever got was having a multiface 1 on my speccy, I could pause and look at code, even save the entire contents of the RAM on to tape and so if I was playing a game I could just save it and then load it back again later and pick up from where I left off.
@@NoelsRetroLab I agree! I have nearly every 8-bit Commodore model (PET, Plus/4, C16, Vic20, C64, C128), now i need to experience more of these machines from the other side of the Pond.
I still have my multiface 128 for the zx spectrum 48/128, same ideas, i also reverse engineered the logic for fun lol. I hacked mine to allow me to save to the Mgt disk drive interface using the Disciple save option and a hardware mod. Well hackable, shadowed ram on top of the rom so i could use the whole interface as the spectrum rom. All of this was done when i was about 20 years old, 30 years later and i still have everything, but the p.c is my running computer now.
Wow, that's awesome! I never got into that level of hardware hacking back in the 80s. That's really impressive with the tools available back in the day actually!
@@NoelsRetroLab What helped was sharp eyes and a 20 year old brain that really wanted to understand how the multiface was wired up, plus a multimeter from tandys for track checking. That was about 35 years back, i drew the diagram in the " Big book of crap" (as i called it) lol. I loved the speccy days as you can tell by my name zx8401, yep memory multiplexer. Pity My memory isn't as good as it was, my multiplexer can't allways get the address right lol. Sorry long waffle, brilliant channel.
Would it be feasible to make a Multiface Pi? Then it might open up the possibilities to get WiFi, save games and load programs over WiFi, or to SD, use the Pi CPU as a coprosessor, or use the RAM as a RAM expansion, etc. Endless possibilities from just one little Raspberry and some glue logic. Maybe?
That's an interesting idea. If we hooked up the Raspberry to the expansion port, could it read all the data fast enough without missing any? I know the Pi is fast, but I don't know how fast the I/O ports are. It would be easy to run some experiments though! Could be a really fun project.
@@NoelsRetroLab It should be possible to do something. The Raspberry Pi (even the original model) is fast enough to act as a coprocessor for the BBC Micro's Tube interface, emulating a 275MHz 6502, or several other processors. You can connect it to the CPC too, as someone designed an Acorn Tube interface for it, plus some supporting software.
Wow ! Thank you very much, awesome review ! I'm a big fan of Amstrad, when I was young I spent lot of time to hack some games or to understand how to do.. But no google at this time so no way... I always wanted one of these interface but in 1988 that was no easy to get one... Thanks agains very nice video
Looking to buy / build one of these. The retro forum is in Spanish, and Rewinding has PM's disabled at the moment. There is apparently an interest list for the MX4 version, and more boards getting made up for the Edge version
Just wanted to add something in ordre to answer your question : AFAIK there were at least two similar devices. I can remember of Siren Software’s Hackit which was not as good as Romantic Robot’s Multiface, by far, since it had no backup capabilities, and memory was sligthly altered when freeze button was pressed. I can also remember of Mirage Imager. Greetings from France, Bye bye !
I'm already hooked to your videos. By the way, would you be interested in inspecting a SNES that freezes while playing Sensible Soccer (maybe its the game cart) or is that outside the scope of your Retro Lab?
Hello! I own a multiface 2. Quick question. When I press stop button, the games pauses but I do not get the multiface's options! What could it be wrong? Reset button works fine in terms of restarting. Thank you in advance.
Hard to say. It could be as simple as the ROM of the Multiface not working, but it could also be something that doesn't allow it to trigger. Did it use to work and then it stopped?
Great video and super interesting. I was just thinking how cool it would be to have something similar for game consoles like the NES, or have a modern version of the Multiface that can save to SD card as well as floppy. Thanks for the great video!
True! It would be tricky on a NES for many different reasons (starting with how do we connect it? Would it be a cartridge with a place to connect another cartridge? Hmm... that's an idea :-)). But yeah, there's definitely potential there. Glad you liked the video!
The closest to this on the consoles has been the Action Replay and the Game Genie. On my GameCube, the Action Replay is bundled with card adapter that allows you to use SD cards.
@@captaincorleone7088 I vaguely remember a Game Genie for an early Nintendo console, can't remember if it was NES or SNES but we definitely had one for the Sega Megadrive.
@@NoelsRetroLab Yes it would go between the cartridge and the console. The Game Genie for Sega Master System and Sega Megadrive consoles did it this way. And as I commented above, I vaguely remember a version for a Nintendo but I am not 100% certain of that without researching.
@@TanjoGalbi There definitely was an NES version of the Game Genie. I remember the attention it received at the time because of Nintendo's attempts to have it pulled from sale. :) bootleggames.fandom.com/wiki/Game_Genie
Has an Invisible mode. Ie The Race won’t load properly if plugged in, however, press the red button and then R and now the MF2 is Invisible. :) There is also a program called Insider that works with the MF2. F11 in WinAPE. Reset Ctrl F9. Love WinAPE! :)
Last time I checked with the designer he said the legality of this is not 100% clear, so that's why it's not just available on Github. I think your best bet is to jump on that forum liked in the description and ask for one with the help of Google Translate 😃
Urgh. The memories of the Spectrum Multiface. M128 LOADING For ages. The bootloader and the three CODE sections, with that blue and yellow message flashing away. M128 LOADING. For the same length of time for every game, being a memory dump. Waiting for it to load. M128 LOADING. Then,you think you are there. It's over. M128 not loading any more. You made it. R Tape loading error 0:1
That looks a nice tool. Almost I want to buy it, just... It seems to requires a disk driver and I have the same CPC464 that you show behind you :) Is that right?. By the way... very handful video as usual from you Noel. :) See you in the next video.
Haha, I don't know why there's an Amstrad CPC 464 there. I must have been restoring it at the time. I actually don't think you need a disk controller. You can use all the debugging and pausing functions with the 464. And you can probably even write to tape... but you would want to do that! So get one! 😃
@@NoelsRetroLab yes, I got one for the CPC464 and you can save to tape. Of course takes quite a while to save to tape. Would be great to save to disc. I bought also the DDI-5 from Zaxxon.Unfortunately none of this modules have a loop through. Do you think there is a possible solution? Is it possible to create a cable where both modules can be attached? Or is it not possible to attach multiple Modules? Do you know somewhere a instruction for creating such a cable?
The board design didn’t have decoupling capacitors. That’s kind of a big no no, especially on a reengineered design. However is not all doom and gloom, one can just tack the capacitors to the underside of the board
You're right, I totally spaced about that. They simply allow you to use different ROMs (the EEPROM there is large enough to hold 4). Maybe you need different ones for Plus vs CPC or some custom ones, not really sure. I haven't touched them at all to be honest.
You can use emulators to save a modern snapshot or on hardware use the board you just soldered together. Why would there be a need for another "modern" version that is not a Multiface?
What I would want out of a modern device is to save the snapshots directly to an SD card, which would be much faster and you could fit many more than on a real floppy disk.
so basic compared to similar tools on C64 but I love this kind of devices! EDIT: I see that the task of this cartridge is much more complicated because of the architecture of the Atari. On the Commodore 64 the job was simpler because the registers and memory of the VIC and SID chip are all mapped in the main CPU's memory area .
"The Multiface allows you to POKE INFINITE LIVES listed in this magazine and you'll never loose." So she'll always be tight no matter how many times I POKE her every time I reincarnate? Sign me up, guv'nah!
I'm afraid not. But all the material is open source, so you could download the files and make one yourself without too much trouble probably. Or you could ask in CPCWiki because I know they did a run there a few years ago. Good luck!
The board design didn’t have decoupling capacitors. That’s kind of a big no no, especially on a reengineered design. However is not all doom and gloom, one can just tack the capacitors to the underside of the board
One clarification: At around 15:00 I simplify things quite a bit by saying the address bus determines who that data is intended for. I left out the part that in the case of a Z80 like we have here, there are also control signals that come into play (/MEMRQ and /IORQ) that determine if the data is intended for the RAM or another chip. There are other architectures that have memory-mapped I/O where the control signals aren't necessary and a specific address is all is needed to target a particular chip.
Ah yes, I was a little confused when you were explaining that since I'm familiar with the Z80 architecture and I/O is treated very differently, not occupying memory address space. Not really a consideration when trying to explain it I know.
I can still read you address on the package that was mail to you... you HAVE TO do better than that if you want your address to stay private.... maybe a few extra layers from the marker next time? - just thought I'd let u know :)
I had the Schneider CPC-464 (German version) and a flight simulation game simulating an Apache Tomcat helicopter.
It had a copy protection - it displayed a pixel pile and one had to use a foldable plastic lens positioned at some marks to read a code that was hidden in the garbled pixels. No matter how I tried, I got the digits wrong in 8 out of 10 cases.
That's why I bought the Multiface II - once I had over one the code deciphering hurdle successfully, I saved the game right there, and from then on I was able to fire up the game and play without that endless annoyance.
These were the times ...
Ah Tomahawk with Lenslok. Good that this died very quickly...
en.m.wikipedia.org/wiki/Lenslok
That was the only CPC game I never managed to convert to disk.
The loader copied itself down to memory location 0 then decrypted itself (I got bored after working through 7 or 8 layers)
I believe the most underrated part is the explanation of how the data/address bus work! I will be constantly referring this to people who want a simple and straight forward explanation about that subject. It was brilliant!
Thank you! Glad you enjoyed that part too!
A college friend of mine and a partner designed a board, which did exactly the same thing for the Apple II, which would have been around 1979-80 from memory. They set up a company and sold huge numbers, mostly in the USA and for a few years it made quite a lot of money. There were attempts by software companies to stop the sale of these type of devices, as they were widely used to bypass copy protection, but they all failed as (officially at least), they were sold as ways of making legitimate backups of software.
So, these sort of boards were around for some years earlier, albeit for different machines.
I have a similar story. I had the Commodore 64 and did exactly the same thing as you, reverse-engineering the code to add infinite lives and stuff like that. I also converted a lot of cassette games to load from the disk drive, adding a small turbo loader to speed things up a bit. This taught me so much about 6502 assembly and also about the Commodore 64 and Disk Drive hardware and memory mapping as well. Good times, I remember them with fondness. By the way this multiface is very similar to the Action Replay and Final Cartridge versions that we had for the Commodore 64. Great Video ;)
Yes, good memories and great experiences that taught us a lot. I don't see most modern computers encouraging that kind of exploration unfortunately.
@@NoelsRetroLab That is the downside to a mature market. Now th sbc:s and microcontroller dev boards fill that function and maybe to some extent android devices.
Noel. You are a true genius in everything you do and how you explain it brilliantly. I have no background in electronics except what I learned myself over the years. My background is industrial automation making today's industrial world more efficient but my love is old stuff. So we'll designed and thought out with what they had. I have bought and repaired vintage amplifiers, twin cassette decks that I now listen to. Long story short I bought 4 items on ebay untested of course. 2 Atari's 2600, both fixed. A commodore 64 PSU issue so today I rebuild a new PSU by hammer and punch literally breaking open a brick of death to get the 9 volt ac transformer and rigged a 5 volt switching charger to the din power plug for the 64 and working perfectly. My problem is my last one an Amstrad cpc 464. Anytime I power it on I get zig zag, horizontal lines but most frequently white screen black border. I have schematics but I work with a magnifying glass a digital multimeter and a hunger to know why and what am I missing. Any ideas and how did you learn all this? Life I know but books, college etc I would be extremely grateful for any information. Best on TH-cam without a shadow of a doubt. Keep posting.
This device was a godsend back in the day. Copying tape games onto disc saved so much time!
This is the first thing I ever saved up for. 4-5 weeks doing two paper rounds. It was brilliant (I sold a whole load of CPC stuff 4 years ago when I moved.... There were three of them in the box!)
I remember cracking "Highway Encounter" to be able to save to diskette and not needing the tape to load it. I found a hidden message from the author (Mark Haigh Hutchinson). I wrote him a letter to the given address (because the message said so) and he even sent me a letter back. I believe he has passed away unfortunately.
I actually made a turbo diskette loader with only one big sector per track which loaded it very fast. And the icing on the cake was, that the loader was started with the |cpm command. This was great fun for a 16 year old😊
I was so pleased with the Multiface One for my ZX Spectrum. At the time it was like a little piece of boxed up magic.
I remember writing Specy BASIC to CAT what was on a microdrive and to present them as menue options :)
I hadn't seen anybody using a rag over the board when you are using IPA, to clean the flux and then using the tooth brush over it. I was always having problems to clean the flux and your method seems to work perfectly well.
Glad that was useful! :-)
Nice clean build and some great technical information shared there, Noel. Skills acknowledged.
Glad you finally got your Multiface II! I had an Action Replay on my Amiga and loved it. Had no clue what this was in my Amstrad days but it would have been a hoot.
Thanks 👍
Excellent explanation of how the device works. Great video! Your proposed new device would be very useful for those with busy lives, allowing them to stop and restart their gaming with little lost time.
That little note "the Multiface II+ must be present, so pirates will find this about as much use as a rubber cutlass."
Sure, unless everyone has one.
I can imagine this was great for kids who only got to play a limited time from their parents, meaning they could actually play the whole game instead of just repeat the first levels.
I remember a friend of mine back in the day had the MF and was using it mostly for copying games, and what a coinsidence to pause HOH, like in this video. I remember begging him for several days to borrow the device for testing, which I got, only to discover that in real world senariors most users wouldn't bother that much about the "pause and save state" memory dump feature but rather for the other major benefit of removing copy protection and transfering software from tapes to disk which did require specific skills that n00bs didn't have. Most of them just wanted to copy and trade games with each other. That was actually my first "gig" in the IT sector back in the '80s as a teenager and let me tell ya, making the equivalent of an adult's salary with minimal effort, was an incredible thing. I was already writing code and even made 3 game clones (pacman, donkey kong, snake) and also messed around with a type of quasi-hardware sprites that were theoretically impossible on the CPC, but it was that period that I got my first serious experience of learning both about hardware and software (albeit I started with a C64 before the Amstrad CPC). Although "technically" illegal in today's terms, it gave me a glimpse of how much money could be made in the computer sector, and after that I never looked back. Over the years I got degrees in programming and design and had multiple careers as IT technician, CG artist, web developer and even got some inventions. Now as far as the Multiface goes, because Discology and Pyradev were able to do the "other half" of MF's major features and there was no need for extra hardware, MF was not as popular as most people think. In fact its because of those abilities especially in Discology, that it became THE software to own for the CPC. I almost made a living because of that thing for several months at the age of 14, providing "reverse backup services" *wink wink* to people that had tons of software on tapes, and paid good money to transfer them to floppy disks. In "partnership" with 2 local computer stores I made the equivalent of 200 euros per week (in todays money adjusted for inflation -- that's a full time salary) and for a teenager of the '80s such easy cash made me feel like I've cleaned up a Casino or something. LOL! So thank you Noel for brining back those "memories" - no pun intended ;-)
Takes me back, i still got the two Multiface's i bought in the original packaging. 1 for my Spectrum 128k and a Multiface for my Spectrum +3. So great
Thank you for the video and all the explanations. I have the Multiface original one, but I havent explored all the options until now.
Some additional details.
The filtering of the I / O addresses of multiface 2 is much more precise than that of the circuits.
Thus, only bit 14 of the address (= 0) is enough to access the CRTC, whatever the value of the other bits
10111100xxxxxxxx = BCxx. Bits 10, 11, 12, 13 and 15, when set to 0, allow access to the other circuits.
(Say otherwise it's possible to address several circuits simultaneously)
So instead of using BC to access the CRTC, you can also use 00111100 = 3C.
One of the many ways to crash a program saved by the multiface is to set all the CRTC registers to 0 on the BC port, and set the normal values with 3C.
So when the multiface wants to reset the values to their correct values, it crashes the machine. It is much simpler than trying to detect the card.
I no longer remember if the interface correctly manages the return address from the interrupt when Z80A Stack Pointer register is located between 0000 and 3FFF when the button is pressed.
It would be also interesting to know how the multiface detects what is the interruption mode of the Z80A when the button is pressed.
Thanks for the details. I didn't know that. I did read that the Multiface fails to return correctly when the stack is located in that area, so that probably confirms your suspicion.
@@NoelsRetroLab You're welcome. The interface is also capable of saving the additional 64k if it has been used by the program. And there is also a software capable of reloading these files without the interface connected. ;-)
You might describe the technique whereby I/O write data is stored on the Multiface II as "bus snooping". That's a term normally applied to caches, but I think it could apply here as well.
Amazing video. I was cracki g games for the c64 back in the day, but I used an action replay mk5 to be able to debug the code and remove copy protection. This did not stop me from learning, because saving a freeze file was considered lame. So the main use for the action replay in this regard was to set a breakpoint on the loading routine, so that we could save the memory before a game would start.
Porting multi level cassette games to disk by saving each chunk of level data and by rewriting the loading routines in the main game was fun too. 😁
Thanks! Yeah, I could see how that would be an amazing tool. Multiload cracks were always so hard!!
What a brilliant video about the multiface 2 Noel, thank you for doing this ! you are a star :)
I used to borrow my friends Muliface 128 for the Speccy in the 80's so I could transfer my games to Microdrives. Last year I found that a Muliface 128 clone had been made. (Probebly the same people that made yours). So now I have my own. Yipee. :)
I used to have an Action Replay, a similar device for the C64. Great little piece of hardware. I used to use it to copy my own tape games to other tapes, I didn't own a disk drive, as the turbo tape loader was much faster. You could get a game that would take around 100 on the tape counter down to 60 or even less in some cases.
On a C60 you could get 5 or 6 games per side, if I remember rightly, and I'd put my original copies away and just use the fast loader. Since you could save where you like, you could just bypass any code style copy protection with ease.
The big issue is that it didn't work on multiload games, for obvious reasons.
I realise that reads wrong... I'm not trying to say the turbo tape loads faster than disk, I was just noting that's why I used tape-to-tape.
Absolutely brilliant video. Great explanation and the info on the “arms race” was very entertaining. Subbed and hit the bell!
Thanks Mark! I love your channel, so that means a lot coming from you.
Great video and walk through, thanks for sharing
I still have mine! I loved looking at the HEX code looking for messages from the programmers
Most likely two transistors in case you don’t read the instructions about the mistake and put it in the wrong way around. So in the case you can cut the old one out, which is a lot easier than de-soldering if you don’t have the correct tools.
Noel, the M4 card has something called hack menu that makes more or less the same thing
Do you have a link to the documentation? I actually looked into it but didn't see anything (just how to load actual SNA files). Thanks!
@@NoelsRetroLab www.spinpoint.org/cpc/m4info.txt
This is amazing! Thank you so much! I came here, because I found out that WinAPE allows to attach a Multiface II ROM. Now I know how it feels like, because I never had one. And naturally many ideas come up: Is it possible to dump my favorite game at a certain level and then transfer it to my real 464? Yes, but you need something like Anti-Multiface which allows to restore a backup without a Multiface present, but Anti-Multiface requires 128kB, but then I found MF2RR which works with 64kB! Hilarious! I tested it successfully!
That's awesome! I hadn't thought of using it for that, but that's a great idea!
I wanted one for my CPC 464+ SO BAD back in the day! The closest I ever got was having a multiface 1 on my speccy, I could pause and look at code, even save the entire contents of the RAM on to tape and so if I was playing a game I could just save it and then load it back again later and pick up from where I left off.
Yeah, it was definitely a dream accessory back then! I never had one either but always wanted one too.
I had two Action Replays for the Amiga.
Had no too much clue how to really utilize it but nevertheless it was a nice and useful device.
I'm a Commodore 64 guy, but watching your videos makes me want to get a CPC.
Nothing wrong with having both! :-)
@@NoelsRetroLab I agree! I have nearly every 8-bit Commodore model (PET, Plus/4, C16, Vic20, C64, C128), now i need to experience more of these machines from the other side of the Pond.
Great video.
I always wanted one of these just for the snaps, now with the M4 I'm fine :-)
I still have my multiface 128 for the zx spectrum 48/128, same ideas, i also reverse engineered the logic for fun lol.
I hacked mine to allow me to save to the Mgt disk drive interface using the Disciple save option and a hardware mod.
Well hackable, shadowed ram on top of the rom so i could use the whole interface as the spectrum rom.
All of this was done when i was about 20 years old, 30 years later and i still have everything, but the p.c is my running computer now.
Wow, that's awesome! I never got into that level of hardware hacking back in the 80s. That's really impressive with the tools available back in the day actually!
@@NoelsRetroLab What helped was sharp eyes and a 20 year old brain that really wanted to understand how the multiface was wired up, plus a multimeter from tandys for track checking.
That was about 35 years back, i drew the diagram in the " Big book of crap" (as i called it) lol.
I loved the speccy days as you can tell by my name zx8401, yep memory multiplexer.
Pity My memory isn't as good as it was, my multiplexer can't allways get the address right lol.
Sorry long waffle, brilliant channel.
Would it be feasible to make a Multiface Pi? Then it might open up the possibilities to get WiFi, save games and load programs over WiFi, or to SD, use the Pi CPU as a coprosessor, or use the RAM as a RAM expansion, etc. Endless possibilities from just one little Raspberry and some glue logic. Maybe?
That's an interesting idea. If we hooked up the Raspberry to the expansion port, could it read all the data fast enough without missing any? I know the Pi is fast, but I don't know how fast the I/O ports are. It would be easy to run some experiments though! Could be a really fun project.
@@NoelsRetroLab It should be possible to do something. The Raspberry Pi (even the original model) is fast enough to act as a coprocessor for the BBC Micro's Tube interface, emulating a 275MHz 6502, or several other processors. You can connect it to the CPC too, as someone designed an Acorn Tube interface for it, plus some supporting software.
funny thing is , romantic robot owner is only up the road from me in London. not sure if he's still about as he's rather old now.
Wow ! Thank you very much, awesome review ! I'm a big fan of Amstrad, when I was young I spent lot of time to hack some games or to understand how to do.. But no google at this time so no way...
I always wanted one of these interface but in 1988 that was no easy to get one...
Thanks agains very nice video
Glad you enjoyed it! I felt the same way back in the 80s. Now it's your chance to build this clone then :-)
I have a Action Replay III for my Amiga A500. I used it for copying disks and helping in games etc.
I never used it, but it sounds very similar to this device. Quite handy!
Hello @NoelsRetroLab . Do you know where MF2 can be bought as DIY kit? Preferably in the EU. Help appreciated!
Looking to buy / build one of these. The retro forum is in Spanish, and Rewinding has PM's disabled at the moment. There is apparently an interest list for the MX4 version, and more boards getting made up for the Edge version
He does have some available. Let him know directly or ping me on Discord/Twitter and I can put you in touch.
@@NoelsRetroLab all sorted. Once the post was approved on the board (new member) he sent me a PM afterwards that he has some in stock. Thanks
Awesome ! Great video Noel !
Just wanted to add something in ordre to answer your question : AFAIK there were at least two similar devices. I can remember of Siren Software’s Hackit which was not as good as Romantic Robot’s Multiface, by far, since it had no backup capabilities, and memory was sligthly altered when freeze button was pressed. I can also remember of Mirage Imager.
Greetings from France,
Bye bye !
You're welcome! Glad you liked it.
1:26 did I just see an ad for an SSD? the silicon disk
I'm already hooked to your videos. By the way, would you be interested in inspecting a SNES that freezes while playing Sensible Soccer (maybe its the game cart) or is that outside the scope of your Retro Lab?
That's outside of my current expertise, but I've been thinking about getting into old consoles as well, so I'd love to have a look at it sometime :-)
Hello! I own a multiface 2. Quick question. When I press stop button, the games pauses but I do not get the multiface's options! What could it be wrong? Reset button works fine in terms of restarting. Thank you in advance.
Hard to say. It could be as simple as the ROM of the Multiface not working, but it could also be something that doesn't allow it to trigger. Did it use to work and then it stopped?
Great video and super interesting. I was just thinking how cool it would be to have something similar for game consoles like the NES, or have a modern version of the Multiface that can save to SD card as well as floppy. Thanks for the great video!
True! It would be tricky on a NES for many different reasons (starting with how do we connect it? Would it be a cartridge with a place to connect another cartridge? Hmm... that's an idea :-)). But yeah, there's definitely potential there. Glad you liked the video!
The closest to this on the consoles has been the Action Replay and the Game Genie. On my GameCube, the Action Replay is bundled with card adapter that allows you to use SD cards.
@@captaincorleone7088 I vaguely remember a Game Genie for an early Nintendo console, can't remember if it was NES or SNES but we definitely had one for the Sega Megadrive.
@@NoelsRetroLab Yes it would go between the cartridge and the console. The Game Genie for Sega Master System and Sega Megadrive consoles did it this way. And as I commented above, I vaguely remember a version for a Nintendo but I am not 100% certain of that without researching.
@@TanjoGalbi There definitely was an NES version of the Game Genie. I remember the attention it received at the time because of Nintendo's attempts to have it pulled from sale. :) bootleggames.fandom.com/wiki/Game_Genie
Hello i would like to buy this kit, but i didn't find any more. Has someone a shopping link adress for buying the kit ?
not for the kit. but retroguru.eu sells them.
Has an Invisible mode. Ie The Race won’t load properly if plugged in, however, press the red button and then R and now the MF2 is Invisible. :)
There is also a program called Insider that works with the MF2.
F11 in WinAPE. Reset Ctrl F9.
Love WinAPE! :)
Does anybody know where i can buy a kit or a link to the pcb design for PCBWay please.
Last time I checked with the designer he said the legality of this is not 100% clear, so that's why it's not just available on Github. I think your best bet is to jump on that forum liked in the description and ask for one with the help of Google Translate 😃
Do you make a multiface 2 for others and if so at what price?
on retroguru.eu you can get it for 40 Euros.Got mine from there. 😀
Urgh. The memories of the Spectrum Multiface.
M128 LOADING
For ages. The bootloader and the three CODE sections, with that blue and yellow message flashing away. M128 LOADING. For the same length of time for every game, being a memory dump. Waiting for it to load. M128 LOADING.
Then,you think you are there. It's over. M128 not loading any more. You made it.
R Tape loading error 0:1
Ugh! I can't imagine using a Multiface but saving to tape. That would be painful indeed!
That actually made me laugh Paul! 🤣
So this is the predecessor of the AMIGA Action Repla,ykind off? AIMGA 4 EVER :) !!! Cheers.
Yes, in a way. This and the ZX Spectrum one, which I'm pretty sure was before this one.
@@NoelsRetroLab Thank you for clearing this up! :). I knew instantly i need this kind of module for my AMIGA, it was worth every penny!
That looks a nice tool. Almost I want to buy it, just... It seems to requires a disk driver and I have the same CPC464 that you show behind you :) Is that right?. By the way... very handful video as usual from you Noel. :) See you in the next video.
Haha, I don't know why there's an Amstrad CPC 464 there. I must have been restoring it at the time. I actually don't think you need a disk controller. You can use all the debugging and pausing functions with the 464. And you can probably even write to tape... but you would want to do that! So get one! 😃
@@NoelsRetroLab hahahaha Such a great salesman you are. Aren't you? actually I wanna one :)
Do you think it can be combined on a CPC464 with only disk, but using the DDI-5 from Zarrox?
@@NoelsRetroLab yes, I got one for the CPC464 and you can save to tape. Of course takes quite a while to save to tape. Would be great to save to disc. I bought also the DDI-5 from Zaxxon.Unfortunately none of this modules have a loop through. Do you think there is a possible solution? Is it possible to create a cable where both modules can be attached? Or is it not possible to attach multiple Modules?
Do you know somewhere a instruction for creating such a cable?
The board design didn’t have decoupling capacitors. That’s kind of a big no no, especially on a reengineered design. However is not all doom and gloom, one can just tack the capacitors to the underside of the board
Just curious: you didn't explain the function of the DIP switches...
You're right, I totally spaced about that. They simply allow you to use different ROMs (the EEPROM there is large enough to hold 4). Maybe you need different ones for Plus vs CPC or some custom ones, not really sure. I haven't touched them at all to be honest.
@@NoelsRetroLab Keep up the good work, and let those vids continue to roll off the NRL production line. Both informative and entertaining.
@@NoelsRetroLab Could it be possible to put your diagnostic tools in one of the ROMs? Would it work?
You can use emulators to save a modern snapshot or on hardware use the board you just soldered together. Why would there be a need for another "modern" version that is not a Multiface?
What I would want out of a modern device is to save the snapshots directly to an SD card, which would be much faster and you could fit many more than on a real floppy disk.
What is needed is something to convert and buffer lets say a +D floppy interface to a hard drive !
what are these Ahms you keep talking about?
so basic compared to similar tools on C64 but I love this kind of devices!
EDIT: I see that the task of this cartridge is much more complicated because of the architecture of the Atari. On the Commodore 64 the job was simpler because the registers and memory of the VIC and SID chip are all mapped in the main CPU's memory area .
So it's an "Action Replay"... :-)
I think so. Every computer had something along these lines. Back in the days where you could really hack stuff just by listening to the busses 😃
"The Multiface allows you to POKE INFINITE LIVES listed in this magazine and you'll never loose."
So she'll always be tight no matter how many times I POKE her every time I reincarnate? Sign me up, guv'nah!
Always wanted one shame the forum is in Spanish is there a english link?
I'm afraid not. But all the material is open source, so you could download the files and make one yourself without too much trouble probably. Or you could ask in CPCWiki because I know they did a run there a few years ago. Good luck!
The board design didn’t have decoupling capacitors. That’s kind of a big no no, especially on a reengineered design. However is not all doom and gloom, one can just tack the capacitors to the underside of the board