MiSTer FPGA Forum

On the Spectrum core I am finding some games work fine in 48K mode but fail in 128k mode. Two examples are Sabre Wulf and Matchday 2. They both load to the end but once the load finishes the screen flashes black and then goes back to a white screen at the prompt.

The thing is I only ever owned a Spectrum 128 toastrack and owned both of them so I know they should work on it. I'd rather use 128 mode if possible as I never owned a 48k.

Does anyone know what might be wrong?

some 48k games dont like being loaded in 128k mode... thats not a mister thing ota just a speccy thing.

As per above Ive owned a spectrum toastrack since I was a kid - lots of 48k games never loaded through the 128 tape loader. We’d always have to load them through the 48k.

Fuzzball wrote: ↑Thu Jun 13, 2024 9:08 pm

On the Spectrum core I am finding some games work fine in 48K mode but fail in 128k mode. Two examples are Sabre Wulf and Matchday 2. They both load to the end but once the load finishes the screen flashes black and then goes back to a white screen at the prompt.

The thing is I only ever owned a Spectrum 128 toastrack and owned both of them so I know they should work on it. I'd rather use 128 mode if possible as I never owned a 48k.

Does anyone know what might be wrong?

It is the combination of 128 and the DIVMMC, you can fix this with an out command

https://www.bytedelight.com/?page_id=1570

lordoftime79 wrote: ↑Thu Jun 13, 2024 9:43 pm

some 48k games dont like being loaded in 128k mode... thats not a mister thing ota just a speccy thing.

I am well aware of that but, as I stated in the original post, I had Matchday 2 on the 128 and loaded it through the tape loader. I didn't have to do anything special back then.

Match Day II is indeed odd - I can't get any version to load on 128 (bar one Z80 snapshot), even a 128k dedicated one or a +3 dsk.

akeley wrote: ↑Fri Jun 14, 2024 9:38 am

Match Day II is indeed odd - I can't get any version to load on 128 (bar one Z80 snapshot), even a 128k dedicated one or a +3 dsk.

Have you tried the folowing command?

OUT 32765,48

If you have a DIVMMC enabled this will change the paging of the 128.

Chris23235 wrote: ↑Fri Jun 14, 2024 11:44 am

akeley wrote: ↑Fri Jun 14, 2024 9:38 am

Match Day II is indeed odd - I can't get any version to load on 128 (bar one Z80 snapshot), even a 128k dedicated one or a +3 dsk.

Have you tried the folowing command?

OUT 32765,48

If you have a DIVMMC enabled this will change the paging of the 128.

That command works and loads Matchday 2. However I never had to do this back in the day so how do I disable DIVMMC? What is DIVMMC? I can see it mentioned in the menus but I can't see where to disable it.

Yep, we should be able to do this without the OUT command. DIVMMC is a modern mass storage device enabling use of SD/CF cards on real ZX Spectrum. It's also emulated in this core so you can load "hdd" images. In OSD there are "Load DIVMMC" and MMC Mode/Version options.

But I didn't know this is enabled by default? Or maybe it's just my old config. Anyway, I can't see any way to disable it (changing the mode to "SD Card" doesn;t seem to help).

akeley wrote: ↑Fri Jun 14, 2024 1:35 pm

Yep, we should be able to do this without the OUT command. DIVMMC is a modern mass storage device enabling use of SD/CF cards on real ZX Spectrum. It's also emulated in this core so you can load "hdd" images. In OSD there are "Load DIVMMC" and MMC Mode/Version options.

But I didn't know this is enabled by default? Or maybe it's just my old config. Anyway, I can't see any way to disable it (changing the mode to "SD Card" doesn;t seem to help).

DIVMMC is implemented in the core by default. According to the documentation there is no way to launch the machine without DIVMMC support, but I am not at home to browse the core settings to check this at the moment.

There is nothing in the core settings to disable it. In my opinion, if it interferes with some games loading then it should be in the core settings but that is just my opinion.

You might have dodgy versions of those games. Match Day 2 was definitely 128k compatible as I had it on my grey +2 and it even has AY sound.

Swainy wrote: ↑Fri Jun 14, 2024 3:33 pm

You might have dodgy versions of those ga
Es. Match Day 2 was definitely 128k compatible as I had it on my grey +2 and it even has AY sound.

I doubt it, I tried most versions from Lady Eklipse's TOSEC set, and one especially marked 128k.

If DIVMMC is baked in, then that'll explain it. Bit odd choice though - should have a toggle.

akeley wrote: ↑Fri Jun 14, 2024 3:54 pm

Swainy wrote: ↑Fri Jun 14, 2024 3:33 pm

You might have dodgy versions of those ga
Es. Match Day 2 was definitely 128k compatible as I had it on my grey +2 and it even has AY sound.

I doubt it, I tried most versions from Lady Eklipse's TOSEC set, and one especially marked 128k.

If DIVMMC is baked in, then that'll explain it. Bit odd choice though - should have a toggle.

If I were you I’d try getting it from Spectrum Computing: https://spectrumcomputing.co.uk/entry/3 ... tch_Day_II

SC files are ok but for serious checking the TOSEC set is much better.

Swainy wrote: ↑Fri Jun 14, 2024 7:48 pm

akeley wrote: ↑Fri Jun 14, 2024 3:54 pm

Swainy wrote: ↑Fri Jun 14, 2024 3:33 pm

You might have dodgy versions of those ga
Es. Match Day 2 was definitely 128k compatible as I had it on my grey +2 and it even has AY sound.

I doubt it, I tried most versions from Lady Eklipse's TOSEC set, and one especially marked 128k.

If DIVMMC is baked in, then that'll explain it. Bit odd choice though - should have a toggle.

If I were you I’d try getting it from Spectrum Computing: https://spectrumcomputing.co.uk/entry/3 ... tch_Day_II

Nope. I just tried it from spectrumcomputing and it does exactly the same thing. The issue is the core not the file.

I've tried at least 6 different versions of the file now. All do the same thing. All of them work on Fuse.

The DIVMMC is baked into the core and can't be disabled. You will have the same issues with certain games as any user trying to load TAP files of these games on a real Spectrum. It is not inaccurate, quite the opposite.
In order to load TAP files on a real Spectrum you need a device like the DIVMMC and this device is the cause for the issue on 128K models. There is now way around this.
You can either fall back to 48K mode or use the OUT command. Same as on a real Speccy.

Chris23235 wrote: ↑Sat Jun 15, 2024 10:48 am

The DIVMMC is baked into the core and can't be disabled. You will have the same issues with certain games as any user trying to load TAP files of these games on a real Spectrum. It is not inaccurate, quite the opposite.
In order to load TAP files on a real Spectrum you need a device like the DIVMMC and this device is the cause for the issue on 128K models. There is now way around this.
You can either fall back to 48K mode or use the OUT command. Same as on a real Speccy.

Each to their own but I would prefer to do what I used to do on my real Spectrum 128k. I still have it - I just can't be bothered to get it out these days. You put the TAP file on an Android device and then,along with using a volume booster app, you use a TAP player app to play the file as if it is a real cassette. Plugged into a Spectrum it then just loads it like any other cassette.

Can the Mister do this? Does it have audio in?

(but then I just thought if DIVMMC is baked into the core it wouldn't make any difference so it would be pointless)

Actually I just found this https://boogermann.github.io/Bible_MiST ... re/adc-in/

I would love the Spectrum core to support this and disable DIVMMC.

Edit: According to sites that sell it, the ZX Spectrum core already supports it so that makes it an even stranger decision to bake DIVMMC into the core.

Fuzzball wrote: ↑Sat Jun 15, 2024 11:44 am

Actually I just found this https://boogermann.github.io/Bible_MiST ... re/adc-in/

I would love the Spectrum core to support this and disable DIVMMC.

Edit: According to sites that sell it, the ZX Spectrum core already supports it so that makes it an even stranger decision to bake DIVMMC into the core.

Why disable? Divmmc gives very nice features like esxdos.

Sword of ianna requires it

jordi wrote: ↑Sat Jun 15, 2024 9:50 pm

Why disable? Divmmc gives very nice features like esxdos.

Sword of ianna requires it

For authencity. Original hardware didn't have DIVMMC built in - it's a modern add on. So, if the DIVMMC could be switched off you should be able to load one of these problem games on the core without using OUT command.

Of course, it's not a big deal, but the devil's in the details. It's a bit like the fact that there's "TR-DOS" option in the 128k machine's menu...far as I know it was not like that on original HW and I've always found it slightly irritating.

akeley wrote: ↑Sun Jun 16, 2024 3:02 am

jordi wrote: ↑Sat Jun 15, 2024 9:50 pm

Why disable? Divmmc gives very nice features like esxdos.

Sword of ianna requires it

For authencity. Original hardware didn't have DIVMMC built in - it's a modern add on. So, if the DIVMMC could be switched off you should be able to load one of these problem games on the core without using OUT command.

Of course, it's not a big deal, but the devil's in the details. It's a bit like the fact that there's "TR-DOS" option in the 128k machine's menu...far as I know it was not like that on original HW and I've always found it slightly irritating.

The TR-DOS option in the 128K Spectrum is there, because of the boot.rom. You can create your own boot.rom, look here for more information:
viewtopic.php?t=6533

Alternatively you can press F11 and enter GLUKPEN menu of the ROM and choose the 128K menu from here.

I never tried to assemble a ROM without the Non-Sinclair roms as I always found them useful. Maybe you can disable the DIVMMC by creating another boot.rom-

The tools are useful but I see the point that cores should preferably enable the base machine to be emulated without modern additions hard coded in.

I never use my spectrum nowadays without the divmmv: they shorten times and provide a satisfying experience by just doing it's job

jordi wrote: ↑Sun Jun 16, 2024 10:17 am

I never use my spectrum nowadays without the divmmv: they shorten times and provide a satisfying experience by just doing it's job

That's great, but we're talking about an option switch for the MiSTer core.

I think the best way here would be contact Sorgelig over Github.
I don't have any interest in this as I don't use the ZX Spectrum core on MiSTer. I see the point in wanting to have a clean machine (even if I always use an ZX Omni, eLeMeNt and n-go and don't want to miss any of the addtional functionality these machines provide), but I think if anybody wants this, then the Github page of the core would be the place to address it.

Chris23235 wrote: ↑Sun Jun 16, 2024 11:18 am

I think the best way here would be contact Sorgelig over Github.
I don't have any interest in this as I don't use the ZX Spectrum core on MiSTer. I see the point in wanting to have a clean machine (even if I always use an ZX Omni, eLeMeNt and n-go and don't want to miss any of the addtional functionality these machines provide), but I think if anybody wants this, then the Github page of the core would be the place to address it.

I will do this when I get a moment. As @akeley stated it isn't a big deal in the grander scheme of things but it would be nice to have. In my opinion, all cores should start off as simulating vanilla hardware with any accessories etc being an option extra in the configs. I do understand though why, in the case of the Spectrum core, DIVMMC was baked in because a lot of people are going to try and use TAP files and then not be able to work out why they don't work. I think it would have been better as a default option that can be disabled rather than baked on though. It makes the audio in accessory for the Mister a bit redundant for the Spectrum.

Fuzzball wrote: ↑Mon Jun 17, 2024 7:53 am

Chris23235 wrote: ↑Sun Jun 16, 2024 11:18 am

I think the best way here would be contact Sorgelig over Github.
I don't have any interest in this as I don't use the ZX Spectrum core on MiSTer. I see the point in wanting to have a clean machine (even if I always use an ZX Omni, eLeMeNt and n-go and don't want to miss any of the addtional functionality these machines provide), but I think if anybody wants this, then the Github page of the core would be the place to address it.

I will do this when I get a moment. As @akeley stated it isn't a big deal in the grander scheme of things but it would be nice to have. In my opinion, all cores should start off as simulating vanilla hardware with any accessories etc being an option extra in the configs. I do understand though why, in the case of the Spectrum core, DIVMMC was baked in because a lot of people are going to try and use TAP files and then not be able to work out why they don't work. I think it would have been better as a default option that can be disabled rather than baked on though. It makes the audio in accessory for the Mister a bit redundant for the Spectrum.

The digital Io board already has the audio in on the board without an addon. Although I dont think many people would every load audio as

a) Its a pain in the arse, exactly like it was in the 80's
b) cassette tapes are now rotting away

FPGA64 wrote: ↑Mon Jun 17, 2024 8:32 am

The digital Io board already has the audio in on the board without an addon. Although I dont think many people would every load audio as

a) Its a pain in the arse, excatly like it waa in the 80's
b) cassette tapes are now rotting away

I load ZX Spectrum games the old school way very often. For many people like me who grew up with it it's just fun (at least on the ZX), that's why devices such as TZXDuino are quite popular. It's not at all "pain in the arse" since you don't have to deal with dodgy tape decks and Chuntey Fields, and can just sit back and relax for 5 minutes.

I have a fairly-sized tape collection and the load succes rate for the original ones is >90% - the rare exceptions are some really mangled ones, so a tape rot is certainly not happening yet. In any case, you can also load games from digital .tzx files via phone, computer, etc.

That said,I don't think there's a big connection with the DIVMMC issue. Most games don't mind it being there and will load fine without using the OUT command.

I think tape loading from a real tape is simply nostalgia, and not of any real use, or value.
Back in '82/83, aged 12, I had the time to load a tape, and that was the only cheap option at that time - unless you could afford an Opus Disk Drive, and the expensive (for that time) 3.5" floppy disks.
Today, in my 50s, I simply don't have that time anymore, and neither do my friends from that time period. 5 mins for one tape, provided it loads, takes 5 mins off of my free time. 3 tapes, could be 15 minutes of loading, rather than 15 seconds. If I have a spare 1 hour, that is down to 45 mins due to loading old tapes. Fine, if you want that real nostalgia for old media, but tapes might not rot, but they can chew-up in your tape deck.

Back to the original topic. Why can't you just use 48k mode, if that is working ?
It shouldn't matter if you owned one or not, you are trying to play Matchday 2, not the actual 48k system.