DIVMMC - where to get 128K ROM

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tomxp411
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DIVMMC - where to get 128K ROM

Post by tomxp411 » Thu Dec 06, 2018 8:08 pm

I ordered a DIVMMC to go with the 128K Spectrum I just bought, and I just discovered that 128 BASIC isn't fully compatible with the DIVMMC. Wouldn't you know it, the entire reason I bought the DIVMMC was to trade BASIC programs with the PC. When I try to use 128K BASIC on FUSE with the DIVMMC enabled, it just crashes.

However, digging through the latest release notes of ESXDOS, there is a note that says:
[17/02/2018] Commands: Added .128 command to test 128K mode using Velesoft's "zx128rom-for-divide" ROM (lordcoxis)
However, I can't find this ROM anywhere. I don't really know the Spectrum scene well, so I'm not sure if there are sites or search engines opaque to Google, but I spent way too much time last night looking for this ROM, only to not find it.

Can anyone point me to this ROM?
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PeterJ
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Re: DIVMMC - where to get 128K ROM

Post by PeterJ » Thu Dec 06, 2018 8:52 pm

There appears to be instructions here:

https://www.bytedelight.com/?p=3155

It's worth reading about USR 0 mode here:

https://faqwiki.zxnet.co.uk/wiki/DivIDE
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tomxp411
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Re: DIVMMC - where to get 128K ROM

Post by tomxp411 » Fri Dec 07, 2018 7:10 am

Thanks. I looked at that, but there are no real instructions there - just a short YouTube video that shows someone opening the NMI screen from 128 BASIC. I can't even get that far on FUSE, but I suppose I should probably wait until I get the actual DIVMMC before I play with this any more.
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1024MAK
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Re: DIVMMC - where to get 128K ROM

Post by 1024MAK » Fri Dec 07, 2018 9:48 am

Velesoft has his own website and posts on the forums at World of Spectrum. The most likely place would be in the hardware sub-forum here.
The WoS forums are not scanned by search engines, so will not show up any results in a search engine.

The DIVMMC is an evolution of earlier DivIDE interfaces, which were primarily designed for 48k ZX Spectrums. These did not support 128k BASIC but would work with the 128k machines at a hardware level. So some 128k games would or could be made to work.

The emulation may not be perfect, the actual hardware may react slightly differently.

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tomxp411
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Re: DIVMMC - where to get 128K ROM

Post by tomxp411 » Fri Dec 07, 2018 6:05 pm

Thanks. I didn't even know there were forums at WoS. I've been using that site to read documentation and download emulation products. (I really love Paul Dunn's IDE - I wish he'd continue to develop that.)
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tomxp411
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Re: DIVMMC - where to get 128K ROM

Post by tomxp411 » Fri Dec 07, 2018 6:23 pm

And here we go...

https://www.worldofspectrum.org/forums/ ... ion/42818/

Velesoft explained the problem, and it makes perfect sense.

The DivIDE (and presumably DivMMC) uses some of the same memory in RAM that the 128K BASIC editor uses. So when you try to execute any commands in 128K BASIC, the system crashes.

His new BASIC ROM excludes the parts of BASIC that the DivIDE uses, so that BASIC and the DivIDE can both be present at the same time. It looks like you have to download and run his patcher, which then saves a new, 32K file out to tape. This is the new, modified ROM image. Since I can't use a single, 32K ROM in FUSE (it only accepts 16K ROM files), I'll just wait until the DIVMMC gets here to try it.

Thanks for your help.
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Re: DIVMMC - where to get 128K ROM

Post by serbalgi » Sun Dec 09, 2018 6:24 am

tomxp411 wrote:
Fri Dec 07, 2018 6:23 pm
Since I can't use a single, 32K ROM in FUSE (it only accepts 16K ROM files), I'll just wait until the DIVMMC gets here to try it.
You could use a file splitter (e.g., HJ-Split) to split the ROM in two halves.
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tomxp411
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Re: DIVMMC - where to get 128K ROM

Post by tomxp411 » Sun Dec 09, 2018 8:01 am

serbalgi wrote:
Sun Dec 09, 2018 6:24 am
tomxp411 wrote:
Fri Dec 07, 2018 6:23 pm
Since I can't use a single, 32K ROM in FUSE (it only accepts 16K ROM files), I'll just wait until the DIVMMC gets here to try it.
You could use a file splitter (e.g., HJ-Split) to split the ROM in two halves.
I was actually considering that; I just realized as I was messing with this that there's really no point: the whole point of using FUSE was to write programs on the PC, and there are better ways to write and test. After discovering BASInc, I don't need a virtual DIVMMC. I can just save out the tokenized BASIC files directly from BASInc.
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1024MAK
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Re: DIVMMC - where to get 128K ROM

Post by 1024MAK » Sun Dec 09, 2018 4:59 pm

To be fair, the 128k BASIC editor is rubbish. In some ways, I prefer the 16k/48k editor, minius the keyword entry system (assuming you are either using an Amstrad machine, a decent third party keyboard, or a emulator on a PC witch a decent keyboard).

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Re: DIVMMC - where to get 128K ROM

Post by tomxp411 » Mon Dec 10, 2018 6:56 pm

1024MAK wrote:
Sun Dec 09, 2018 4:59 pm
To be fair, the 128k BASIC editor is rubbish. In some ways, I prefer the 16k/48k editor, minius the keyword entry system (assuming you are either using an Amstrad machine, a decent third party keyboard, or a emulator on a PC witch a decent keyboard).
To tell you the truth, after using the 128K for a few days, I'm very disillusioned with it. The space bar is awful, and I can't get over the weird key positioning - putting the backspace key where the tab key should be and shifting all the letter keys to the right by one space. So the Spectrum is now just sitting on top of my Altair Clone and probably won't actually get used as anything other than a door stop or the occasional demo.

I suppose if someone was to point out a couple of Spectrum-exclusive games that are worth playing, i'd bust it out for those, but mostly I was interested in how Sinclair BASIC is different than Microsoft BASIC, and BASin is a much more friendly development tool.

When the DIVMMC finally gets here, I'm certainly going to try the instructions above to create a custom ROM that works with the MMC, but really, USR 0 mode is fine for the things I'll be doing with the machine. (And despite its flaws, the Recreated is as good a keyboard as the 128, thanks to the 128's weird design.)
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