Page 1 of 1

BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 7:37 pm
by rhester72
Please note: This is coming from a US-based user who has never seen, nor known anyone personally who has ever seen a BBC Micro or Master in their lives and has absolutely no concept whatsoever what they are doing, particularly with MMB.

That being said, in my quest to play the 'ultimate' version of Elite (which by all accounts is, indeed, the BBC Master coprocessor-powered one), I've managed to get a MMB called 'boot' to autoboot on start, and in either BBC Model B or Master 128K mode, _so long as the coprocessor is disabled_, all works as expected, a menu of games is presented, I can select one and off we go. Fabulous.

However, if I enable the coprocessor, I instead get the following on boot:

Code: Select all

Acorn TUBE 65C102 Co-Processor

Master MMFS (FE80)

BASIC

>*TV255
>*MENU

Tube on!
>_
...and that's it. I can interact with the prompt (BASIC, I presume? Things like PRINT work...) but have absolutely no idea what I'm supposed to be doing from here to either get the menu to come up, catalog the VHD or manually start a game.

With sincere apologies for my ignorance, can anyone clue me in on what I'm very obviously doing wrong?

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 9:14 pm
by lamarax
*CAT maybe? :? Although that won't work with .MMBs converted renamed to .vhd I'm afraid.

Try the updated core by alanswx:
BBCMicro_20220123.rbf
(3.61 MiB) Downloaded 182 times
...with which you can load individual disk images (.ssd).

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 9:31 pm
by rhester72
Well now that's curious...Alan's build sort of works.

I got a one-disk version with all 4 versions of BBC Elite from Ian Bell's site (attached), which refers to the coprocessor version as the '6502 Second Processor Elite Executive Version'. It successfully boots, but upon selecting the copro version, I get "Sorry, this version requires a 6502 second processor. Please turn on your Tube and press SHIFT+BREAK."...but I've enabled the coprocessor and reset already. I also did as instructed with CTRL-F11, both shifted and unshifted, which apparently just does a hard reset but there's no change in behavior...something about the copro detection code doesn't appear to like the MiSTer core.

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 9:43 pm
by akeley
I think the new core version only works with floppy in BBC Master mode? Did you manage to use the floppy in B mode?

EDIT: I tried your disk and yeah, seems you're running in Master mode. I get the same "needs coprocessor" message for Executive Elite, and when I try the Master Elite, it works fine. Seems these versions are siginificantly different and won't run on both machines.

MMBeeb menu is not compatible with the Tube, hence the Tube on! error. You can probably make your own vhd, put that Elite version on it and try to boot from Basic. I have one Menu-less vhd and can use coprocessor and boot some games, though most of them crashes. Not sure if that's a problem, or how it really was.

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 9:45 pm
by lamarax
Is the tube modeled after the 6502 co-pro? I think it's the Z80 as in Torch

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 9:53 pm
by rhester72
akeley wrote: Wed Feb 02, 2022 9:43 pm I think the new core version only works with floppy in BBC Master mode? Did you manage to use the floppy in B mode?
Negatory, but the floppy in question is something I'm trying to run in Master mode, so that's OK LOL

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 9:54 pm
by rhester72
lamarax wrote: Wed Feb 02, 2022 9:45 pm Is the tube modeled after the 6502 co-pro? I think it's the Z80 as in Torch
Not sure what you're asking...the game claims it can't find a 6502 copro, the core says it's a 65C02...not sure if that's material to the detection routine.

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 10:07 pm
by akeley
rhester72 wrote: Wed Feb 02, 2022 9:53 pm Negatory, but the floppy in question is something I'm trying to run in Master mode, so that's OK LOL
Aye, but like I said above, the Executive Elite is not compatible with BBC Master, so this will leave you with Master Elite - which is quite an interesting version too apparently.

It was interesting to read about all these different Elite verisons, there seems to be a lot of them, with a heap of difefrences: https://www.bbcelite.com/compare/featur ... rison.html

Amusingly, Mr. Bell recommends the NES version...
sacrilege :)

Re: BBC Master coprocessor confusion

Posted: Wed Feb 02, 2022 10:57 pm
by rhester72
I get it now...right, a B with a tube/second processor will work with the SNG45 and Executive editions, but not a Master. (I'm still learning about all the hardware variations... ;)

That means my 'dream' setup will require Alan's core to support SSD on the B, which it currently does not. Bummer. =)

Re: BBC Master coprocessor confusion

Posted: Thu Feb 03, 2022 4:46 am
by alanswx
The B has a different disk controller I believe. We have the disk controller working on Master. Tapes work on electron soon. The bbc is missing two chips to allow it to have tape and serial support.. is the software on tape?

Re: BBC Master coprocessor confusion

Posted: Thu Feb 03, 2022 7:29 pm
by akeley
akeley wrote: Wed Feb 02, 2022 10:07 pm the Executive Elite is not compatible with BBC Master
Seems I was wrong about that. This site says that SNA45 version should work on Master + coprocessor too (and so I assume Executive version as well). I did try to run it from their disk and it still fails as before though. Perhaps in-core problem?

I did however manage to get it running on Micro B with the, ahem, "Tube" on, by adding disks to my custom vhd(attached here). The Elite disks are in slots 20-23 (SNA45 & Executive versions + flicker free ones). There is no menu, you need to use *DBOOT command (eg *DBOOT 20 for SNA45 version).

Re: BBC Master coprocessor confusion

Posted: Thu Feb 03, 2022 8:35 pm
by rhester72
@akeley I'll have to test tomorrow, but I am curious...how did you get them working? Did you modify them in some way?

Re: BBC Master coprocessor confusion

Posted: Thu Feb 03, 2022 9:38 pm
by akeley
Not really, I just added the disks to the vhd, which I think originally is the beeb.mmb file, which in turn is like a container with ~500 disk slots you can fill (this is my very crude understanding, mind, I'm not a Beeb expert).
Some pre-made mmbs have these fancy menus which boot on start and let you choose games, but it's a lot of work to modify them (have to use MS Access) so I just fill the slots and boot them from Basic. In this case menu wouldn't work anyway because of the coporcessor.

You can try making your own collections with this mmb manager-imager program. Just point it to a vhd (need to rename it to .mmb 1st, and then back to .vhd when using it on MiSTer)

Re: BBC Master coprocessor confusion

Posted: Fri Feb 04, 2022 8:07 am
by GreyAreaUK
I'm actually working on my own (Windows only, sadly) MMB File Manager called 'MuMBler'. Early days yet and my free coding time is limited, but if I ever get it working properly it'll be free for the asking:

Dp83PJs.png
Dp83PJs.png (1.28 MiB) Viewed 2832 times

Re: BBC Master coprocessor confusion

Posted: Sat Feb 05, 2022 2:01 pm
by MisterPhil
I think the ultimate version of Elite is generally regarded to be the Archemedes version
- maybe you can try that one?

https://www.youtube.com/watch?v=agaVY_w3DYI