Master Vs B

discuss both original and modern hardware for the bbc micro/electron
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drfloyd
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Master Vs B

Post by drfloyd »

hi,

I am starting looking for my first BBC Computer, hope I can find one here :) If you sell one, contact me :)

BBC B or Master, I will see...

My question is :

it is possible de convert a Model B to the advantages of the Master ? (128K, Basic 4, etc...)

To resume : What are the advantages of the Master that Model B cannot have (even with hardware update) ?

Thanks
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richardtoohey
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Re: Master Vs B

Post by richardtoohey »

Well, you can (probably!) technically upgrade a Mini into a Ferrari ... but it wouldn't make sense to do so (or try and do so).

I found this old article the other day; might be of interest:

http://chrisacorns.computinghistory.org ... erWork.pdf
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danielj
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Re: Master Vs B

Post by danielj »

The three main things that the master has over the B are sideways RAM slots (i.e. paged RAM, 64kb of this), Shadow Screen RAM which means the display doesn't have to reside in the main memory, freeing up space for programs, and additional memory that can be used for file system workspace etc.

You can get the beeb to do all of these things to some extent - sideways RAM is easy, just plug in static RAM chips. Shadow RAM is feasible - there are shadow RAM boards, but they don't work in the same way as the Master and might break compatibility with things, and the additional memory used for filesystem workspace and so on, I don't think there's a way of doing that particularly (you'd need re-written filesystems - this may have been done, someone can probably correct me on it).

You can stick in a CMOS processor and run BASIC 4, but you risk breaking compatibility with things that expect to be running with an NMOS processor and BASIC 2 (which they will if they're on a BBC Micro).

The Master is a well defined hardware platform, it has all the things above, it can write to screen/shadow screen even when it's not the currently displayed screen (I don't believe any of the BBC Micro things can do this), it had cartridge slots, it has properly buffered ports, it has an internal and external TUBE interface, and it has CMOS RAM that can store configuration options. The filesystems don't take up any user RAM.

You can't really turn a beeb into a Master. E.g. you're never going to be able to run Prince of Persia on a BBC Micro. If you want a Master, get a Master.

Some other people will probably have more detailed things to say :D. The Master is the more capable machine, lots of people have more of a soft spot for the BBC Micro. I personally prefer the Master :)
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Re: Master Vs B

Post by Naomasa298 »

danielj wrote:
Mon Jun 15, 2020 9:39 am
You can get the beeb to do all of these things to some extent - sideways RAM is easy, just plug in static RAM chips.
You had to do some soldering, didn't you, to provide a write signal?
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Re: Master Vs B

Post by drfloyd »

very clear reply ! THANK YOU

I suppose that the real fans have got the both computers :)
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danielj
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Re: Master Vs B

Post by danielj »

Naomasa298 wrote:
Mon Jun 15, 2020 9:55 am
You had to do some soldering, didn't you, to provide a write signal?
Yes, it does need that, but once you've done it sideways RAM is sideways RAM. The other bits are the things that behave a bit differently.
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Re: Master Vs B

Post by Naomasa298 »

You could always go the worst of both worlds and get a B+. :lol:
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BigEd
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Re: Master Vs B

Post by BigEd »

This is an easy one for you, drfloyd, because you've expressed an interest in cartridges - that means you need a Master. (Or a rather expanded Electron, but that's a whole different set of tradeoffs.)

For me, back in the day I had a Beeb, and now I have two, or three (one has gone wandering) - but I also have a Master now, and that's the machine I use all the time.

It's probably cheaper to go with Beeb + Boobip RAMs + MMFS storage + Pi, but it seems to me you're heading for Master + Gotek + Pi.
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Re: Master Vs B

Post by mr-macrisc »

Depends what you want to do but personally I reckon Master with multi OS from retro clinic (gives you two master MOS, 1x bbc b+ MOS and 1x bbc b one available bury turning rotary switch.

Why do I say this well there are a number of new game releases that are Master only and the number bbc games that still won’t run on a master after installing multi OS is very small indeed😊. Had multi is not have been avail I reckon choice would be harder but with a few more larger master only games on way then defo way I’d go
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danielj
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Re: Master Vs B

Post by danielj »

Naomasa298 wrote:
Mon Jun 15, 2020 10:01 am
You could always go the worst of both worlds and get a B+. :lol:
Poor old B+! :)
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Re: Master Vs B

Post by drfloyd »

what is the problem with the B+ ??????
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Re: Master Vs B

Post by Coeus »

What is worth doing depends on what you want to use the machine for.

If you want to write your own programs have a selection of sideways ROMs loadable from disc and have more RAM available then it is certainly possible to make upgrades to a BBC B to make it closer to a master.

Sideways RAM has already been mentioned - there are quite a few options here. See the generic hardware list sticky at the top of this thread.

For screen shadow RAM there were some boards back in the day including the Integra, one from Watford and another whose name temporarily escapes me, except to say I think it was the subject of a patent dispute between Chris Jordan and Acorn. Ken Lowe has developed a modern re-make of the Integra - this includes sideways RAM too so if you're doing to get this you don't need to do the sideways RAM separately. This board also has some upper workspace.

Chris Morley does a range of small RAM modules (including sideways RAM) one of which is OS RAM. This is RAM that sits in the same part of the address space as the OS ROM and uses some clever tricks to enable user programs to use this RAM while the OS can execute from ROM normally. You can use this space for BASIC and it is also possible to modify filing systems to put their workspace here.

If you get the right one (compatible pinout), a 65C02 can be substituted for the NMOS 6502. You may have to solder a capacitor across it to make it work reliably, though. There is a thread on here about doing exactly that.

Doing some or all of those can give you a machine that had advantages compared to the BBC B, though the 65C02 will break compatibility with anything that relies on the undocumented instructions of the NMOS 6502.

Hardware wise, what you won't get is the ability to update one bank of memory whist displaying the other and then flip them - something a game written specifically for the master may rely on. Software-wise I am not sure anything would be as slick as the OS supplied with the Master which obviously supports the extra hardware. Individual extensions may come with support in ROM and, as I said earlier, it is possible to make other modifications, but much depends on how much you like to tinker.

So, in the end, I got a Master too to supplement the BBC B I already had from the 1980s. If you have neither and are looking to buy the first one then again it will be down to what you want to use it for. The Master is the better machine for doing your own development on and there are some games written especially for it, but there are also ones that are not compatible because they rely on BBC B specific hardware (like the 8271, for example).
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sydney
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Re: Master Vs B

Post by sydney »

mr-macrisc wrote:
Mon Jun 15, 2020 10:21 am
Depends what you want to do but personally I reckon Master with multi OS from retro clinic (gives you two master MOS, 1x bbc b+ MOS and 1x bbc b one available bury turning rotary switch.
This.
Most (all?) of the BBC games should work in BBC mode, most demos require a master. The stuff from Bitshifters - Prince of Persia and Stunt Car Racer - needs a master. Some games are master enhanced. I also think developing software is easier for the master as you have all that RAM and double buffering pretty much for free so probably anything I write will have the master in mind.
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Re: Master Vs B

Post by mr-macrisc »

sydney wrote:
Mon Jun 15, 2020 11:11 am
mr-macrisc wrote:
Mon Jun 15, 2020 10:21 am
Depends what you want to do but personally I reckon Master with multi OS from retro clinic (gives you two master MOS, 1x bbc b+ MOS and 1x bbc b one available bury turning rotary switch.
This.
Most (all?) of the BBC games should work in BBC mode, most demos require a master. The stuff from Bitshifters - Prince of Persia and Stunt Car Racer - needs a master. Some games are master enhanced. I also think developing software is easier for the master as you have all that RAM and double buffering pretty much for free so probably anything I write will have the master in mind.
Sure there are games that have things in them that need the bbc cpu or hardware to work so even with multi os the masters hardware and diff cpu mean they still won’t work. Multi os fixes most stuff but sure there are some it doesn’t fix.

I’d still take master with multi os as a choice if I was to have one machine :)
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sydney
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Re: Master Vs B

Post by sydney »

I'm sure zalaga uses the 'illegal' opcodes in the 6502 so doesn't work and like you say there will be a handful of others too but Prince of Persia, Stunt Car Racer and the demos more than make up for them.
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Re: Master Vs B

Post by mr-macrisc »

Totally agree :)
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Re: Master Vs B

Post by Kazzie »

drfloyd wrote:
Mon Jun 15, 2020 10:35 am
what is the problem with the B+ ??????
Mainly the fact that the extra features it added (mainly extra sideways RAM) weren't used by software programmers, because they targeted the B or Master. The reason for this is that relatively few B+ machines were made.
BBC Model B 32K issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
RiscPC 600 under repair
Acorn System 1 home-made replica
Naomasa298
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Re: Master Vs B

Post by Naomasa298 »

BITD there were also some incompatibility problems, as the B+ came with the 1770 floppy disc controller rather than the 8271, which meant that some games that relied on the 8271 for disc protection wouldn't work. And Repton Infinity didn't like the B+ either, I dunno why though.

Sideways RAM wasn't that useful for many home users as you can't use it from BASIC.
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KenLowe
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Re: Master Vs B

Post by KenLowe »

drfloyd wrote:
Mon Jun 15, 2020 9:25 am
it is possible de convert a Model B to the advantages of the Master ? (128K, Basic 4, etc...)
According to Acorn, the closest you could get was to install an IntegraB board into your Model B:
Acorn 7th May 1991 IntegraB recommendation.jpg
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Re: Master Vs B

Post by Kazzie »

Naomasa298 wrote:
Mon Jun 15, 2020 12:28 pm
BITD there were also some incompatibility problems, as the B+ came with the 1770 floppy disc controller rather than the 8271, which meant that some games that relied on the 8271 for disc protection wouldn't work. And Repton Infinity didn't like the B+ either, I dunno why though.
8271/1770 compatibility issues existed on the plain B itself too. The B+ board supported installing an 8271 instead, though it seems that they all got shipped with 1770s. (Has anyone come across an 8271-fitted B+?)
BBC Model B 32K issue 7, Sidewise ROM board with 16K RAM
Archimedes 420/1 upgraded to 4MB RAM, ZIDEFS with 512MB CF card
RiscPC 600 under repair
Acorn System 1 home-made replica
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tricky
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Re: Master Vs B

Post by tricky »

Only things you have/can't have:
Master and Compact have shadow ram that lets you double buffer a "full" screen read/write are independent of which is displayed.
B and B+ can have a Speech processor, which didn't get much love, but I support it for Astro Blaster which really isn't the same game without it!
As you mentioned, both is a good option and you always have a spare :)

https://youtu.be/-9X8fRGjmJ8 best watched in 720p on a 50Hz monitor.
The version on the menu plays samples at the beginning to "speak" the attract mode.
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Re: Master Vs B

Post by drfloyd »

tricky wrote:
Mon Jun 15, 2020 3:24 pm
B and B+ can have a Speech processor
Why not on Master ??????

The Speech is the same as Parsec on ti99 4/A :)
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richardtoohey
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Re: Master Vs B

Post by richardtoohey »

Obviously the solution is to have one of at least the following:

Atom
Electron (at least one, you might need to also get the Plus 1 and Plus 3)
BBC A
BBC B
BBC B & 8271
BBC B & 1770
BBC B+ 64K
BBC B+ 128K
BBC Master
BBC Master Compact

There, that was easy! :twisted:
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sweh
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Re: Master Vs B

Post by sweh »

sydney wrote:
Mon Jun 15, 2020 11:19 am
I'm sure zalaga uses the 'illegal' opcodes in the 6502 so doesn't work
The copy protection code definitely does (I remember that from BITD 'cos EXMON disassembly was painful; lots of scribbling notes to break it). I don't know if the run-time itself used it, once the copy protection was bypassed.
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richardtoohey
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Re: Master Vs B

Post by richardtoohey »

It definitely did - the run-time - you got funny aliens without the corrected version.

There's a better link than this one, but this will do: viewtopic.php?t=2651
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