what's the use of Mode 0

for bbc micro/electron hardware, peripherals & programming issues (NOT emulators!)
Post Reply
Viper21
Posts: 6
Joined: Tue Aug 06, 2019 5:33 am

what's the use of Mode 0

Post by Viper21 » Tue Aug 13, 2019 7:44 am

other than being used for ASM
C64: HULK SMASH!!!
PET:HULK SMASH...AGAIN!
Plus 4: HULK IS GETTING TIRED!
SX-64: MY ARMS HURT!
C128: (as Banner) no...strength...left (collapses)
BBC Micro: "I like it" :D

User avatar
hoglet
Posts: 8365
Joined: Sat Oct 13, 2012 6:21 pm
Location: Bristol
Contact:

Re: what's the use of Mode 0

Post by hoglet » Tue Aug 13, 2019 7:52 am

Viper21 wrote:
Tue Aug 13, 2019 7:44 am
other than being used for ASM
Word processing?

Spreadsheets?

Databases?

Anything that needs higher resolution graphics (i.e. 640x256 rather than 320x256)?

Dave

cmorley
Posts: 937
Joined: Sat Jul 30, 2016 7:11 pm
Location: Oxford
Contact:

Re: what's the use of Mode 0

Post by cmorley » Tue Aug 13, 2019 8:09 am

80 column text.

User avatar
flaxcottage
Posts: 3674
Joined: Thu Dec 13, 2012 8:46 pm
Location: Derbyshire
Contact:

Re: what's the use of Mode 0

Post by flaxcottage » Tue Aug 13, 2019 8:44 am

CAD?
- John

Image

johnkenyon
Posts: 211
Joined: Wed Jul 20, 2011 2:21 pm
Location: Coventry
Contact:

Re: what's the use of Mode 0

Post by johnkenyon » Tue Aug 13, 2019 9:42 am

cmorley wrote:
Tue Aug 13, 2019 8:09 am
80 column text.
You can do that in Mode 3.

User avatar
jgharston
Posts: 3597
Joined: Thu Sep 24, 2009 11:22 am
Location: Whitby/Sheffield
Contact:

Re: what's the use of Mode 0

Post by jgharston » Tue Aug 13, 2019 9:49 am

johnkenyon wrote:
Tue Aug 13, 2019 9:42 am
cmorley wrote:
Tue Aug 13, 2019 8:09 am
80 column text.
You can do that in Mode 3.
Full-screen 80-column text.
80-column text with graphics.

Code: Select all

$ bbcbasic
PDP11 BBC BASIC IV Version 0.25
(C) Copyright J.G.Harston 1989,2005-2015
>_

User avatar
lurkio
Posts: 2147
Joined: Tue Apr 09, 2013 11:30 pm
Location: Doomawangara
Contact:

Re: what's the use of Mode 0

Post by lurkio » Tue Aug 13, 2019 9:57 am

Game title screens converted from dodgy sources.

1.png
http://bbcmicro.co.uk/game.php?id=2026

:wink:
Last edited by lurkio on Tue Aug 13, 2019 10:19 am, edited 1 time in total.

User avatar
Lardo Boffin
Posts: 1612
Joined: Thu Aug 06, 2015 6:47 am
Contact:

Re: what's the use of Mode 0

Post by Lardo Boffin » Tue Aug 13, 2019 10:16 am

Nice image!
Atom, issue 5
BBC model B 32k issue 4, 16k sideways RAM, Watford 12 ROM board, Acorn 6502 coproc
BBC model B 32k issue 7, turboMMC, Opus Challenger 3 512k, Pi 3 coproc
USA Model B
BBC Master, Datacentre + HDD, pi co-proc, econet, NULA

User avatar
1024MAK
Posts: 9049
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: what's the use of Mode 0

Post by 1024MAK » Tue Aug 13, 2019 1:12 pm

The real purpose of MODE 0 is to have one of the highest graphics screens on a Beeb compared to contemporary competitors home computers...

Mark

User avatar
AndyF
Posts: 1270
Joined: Sat Feb 23, 2008 10:16 pm
Location: Derby
Contact:

Re: what's the use of Mode 0

Post by AndyF » Tue Aug 13, 2019 4:33 pm

Spreadsheet or similar / database type listing would be my thought on it. :)

A tongue-in-cheek comment here would be to say "to annoy people who used RF out with a standard TV" as the ghosting effect/quality was not brilliant in M0, hampered in some cases by slightly iffy and ancient television sets. :lol: :oops:
Last edited by AndyF on Tue Aug 13, 2019 4:33 pm, edited 1 time in total.
Andy

* NEW * The Jetset Willy and Manic Miner community :)

Adventure games ported across to the BBC (in progress) as soon as I can find some time!

User avatar
kieranhj
Posts: 806
Joined: Sat Sep 19, 2015 10:11 pm
Location: Farnham, Surrey, UK
Contact:

Re: what's the use of Mode 0

Post by kieranhj » Tue Aug 13, 2019 4:38 pm

Making lovely hi-res copper colours on a Beeb? :wink:

viewtopic.php?f=53&t=15300#p207230
Bitshifters Collective | Retro Code & Demos for BBC Micro & Acorn computers | https://bitshifters.github.io/

User avatar
danielj
Posts: 7399
Joined: Thu Oct 02, 2008 4:51 pm
Location: Manchester
Contact:

Re: what's the use of Mode 0

Post by danielj » Tue Aug 13, 2019 4:40 pm

Alas, people, Viper21 was a reincarnation of a user who was previously banned for trolling. Suffice to say this was another one of his lo-fi attempts and he's been banned again.
Last edited by danielj on Tue Aug 13, 2019 4:41 pm, edited 1 time in total.

User avatar
tricky
Posts: 3600
Joined: Tue Jun 21, 2011 8:25 am
Contact:

Re: what's the use of Mode 0

Post by tricky » Tue Aug 13, 2019 4:50 pm

Or to run games at their native resolution http://bbcmicro.co.uk/game.php?id=3027 ;)

User avatar
jonb
Posts: 2544
Joined: Sat May 21, 2011 12:42 pm
Location: South Coast of England
Contact:

Re: what's the use of Mode 0

Post by jonb » Tue Aug 13, 2019 7:25 pm

1024MAK wrote:
Tue Aug 13, 2019 1:12 pm
The real purpose of MODE 0 is to have one of the highest graphics screens on a Beeb compared to contemporary competitors home computers...

Mark
This.

I well remember the excitement it caused. Little did we know there would be no memory left to use it!

User avatar
kieranhj
Posts: 806
Joined: Sat Sep 19, 2015 10:11 pm
Location: Farnham, Surrey, UK
Contact:

Re: what's the use of Mode 0

Post by kieranhj » Tue Aug 13, 2019 8:46 pm

danielj wrote:
Tue Aug 13, 2019 4:40 pm
Alas, people, Viper21 was a reincarnation of a user who was previously banned for trolling. Suffice to say this was another one of his lo-fi attempts and he's been banned again.
That’s a shame (the trolling, not the banning) because it’s a genuinely interesting question and I do consider MODE 0 to be one of the Beeb’s more defining features. I’ve often pondered what a MODE 0 only demo might be.

I remember at one early ABUG I attended, flynnjs explained to me more about how PAL TVs work and I realised that the weird yellow and purple strobing you sometimes get in MODE 0 on a low-res TV is the same effect as ‘artefact colour’ on an Apple II, albeit completely uncontrollable. Cue a short and abortive attempt to overclock his Model B with the PAL crystal which survived all of about 10 seconds before overheating. :lol:
Bitshifters Collective | Retro Code & Demos for BBC Micro & Acorn computers | https://bitshifters.github.io/

RobC
Posts: 2655
Joined: Sat Sep 01, 2007 9:41 pm
Contact:

Re: what's the use of Mode 0

Post by RobC » Tue Aug 13, 2019 9:36 pm

I always assumed that it was for word processing and spreadsheets as the dot-matrix printers around at the time were 80-column. If you wanted your micro to be considered as a "serious" machine for business use, it had to be capable of producing an 80-column display. (c.f. this video by the 8-bit guy).

I thought that the BBC must have stipulated that it should be capable of producing a proper 80-column display (i.e. not using squashed 4-pixel characters as seen on lesser platforms :D ) but, looking at the outline spec, they only said this was preferable and could be an optional extra.

User avatar
1024MAK
Posts: 9049
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: what's the use of Mode 0

Post by 1024MAK » Tue Aug 13, 2019 9:57 pm

Don’t forget there is also MODE 3...

Mark

steve3000
Posts: 2020
Joined: Sun Nov 25, 2012 12:43 am
Contact:

Re: what's the use of Mode 0

Post by steve3000 » Tue Aug 13, 2019 11:17 pm

RobC wrote:
Tue Aug 13, 2019 9:36 pm
looking at the outline spec, they only said this was preferable and could be an optional extra.
Although I've not read the spec, you could argue that MODE 0 was an optional extra, since it was not present on the Model A...?

Diminished
Posts: 161
Joined: Fri Dec 08, 2017 9:47 pm
Contact:

Re: what's the use of Mode 0

Post by Diminished » Wed Aug 14, 2019 1:29 am

AndyF wrote:
Tue Aug 13, 2019 4:33 pm
A tongue-in-cheek comment here would be to say "to annoy people who used RF out with a standard TV" as the ghosting effect/quality was not brilliant in M0, hampered in some cases by slightly iffy and ancient television sets. :lol: :oops:
A slightly less tongue-in-cheek comment would be "to annoy people who 32K-upgraded early Model As that had been shipped with 'bad-yield' Video ULA parts deliberately left out of Model Bs."

The struggle was real.

User avatar
jonb
Posts: 2544
Joined: Sat May 21, 2011 12:42 pm
Location: South Coast of England
Contact:

Re: what's the use of Mode 0

Post by jonb » Wed Aug 14, 2019 10:29 am

Just thinking about it for a moment.. with a co-processor and Mode 0 on a decent monitor you could do all sorts of business like things without worrying about the memory constraints I alluded to. In other words, one might say the purpose of Mode 0 is to facilitate more professional uses of the machine.

User avatar
1024MAK
Posts: 9049
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: what's the use of Mode 0

Post by 1024MAK » Wed Aug 14, 2019 6:47 pm

jonb wrote:
Wed Aug 14, 2019 10:29 am
Just thinking about it for a moment.. with a co-processor and Mode 0 on a decent monitor you could do all sorts of business like things without worrying about the memory constraints I alluded to. In other words, one might say the purpose of Mode 0 is to facilitate more professional uses of the machine.
Oh Jon, you’re spoiled the fun by coming out with a very sensible and logical answer #-o

Of course that is exactly what MODEs 0 and 3 are designed for, professional productive applications.

If you have a BBC B (or Master) with a dual floppy drive and a second processor, then that is equivalent to some business computers that Acorn produced. See Acorn Business Computer and Acorn Cambridge Workstation...

Mark

Coeus
Posts: 1313
Joined: Mon Jul 25, 2016 11:05 am
Contact:

Re: what's the use of Mode 0

Post by Coeus » Thu Aug 15, 2019 1:19 am

1024MAK wrote:
Wed Aug 14, 2019 6:47 pm
If you have a BBC B (or Master) with a dual floppy drive and a second processor, then that is equivalent to some business computers that Acorn produced. See Acorn Business Computer and Acorn Cambridge Workstation...
I suppose with a long-term plan based on 2nd processors and, according to Steve Furber, this had been the plan before they suddenly focused on the BBC contract, the high use of memory would not be a worry but for anyone who would be tempted to use the BBC standalone for some kind of professional application it seems surprising that there was not a 80 column text-only character mapped rather than bitmapped mode, i.e. similar to the way the teletext mode worked and exactly the arrangement the 6845 was originally designed for.

Given the teletext it would be an obvious candidate to consider. Would it not go fast enough for 80 columns?

User avatar
DutchAcorn
Posts: 2101
Joined: Fri Mar 21, 2014 9:56 am
Location: Maarn, Netherlands
Contact:

Re: what's the use of Mode 0

Post by DutchAcorn » Thu Aug 15, 2019 7:27 am

Coeus wrote:
Thu Aug 15, 2019 1:19 am
...

Given the teletext it would be an obvious candidate to consider. Would it not go fast enough for 80 columns?
This was discussed before in this thread: viewtopic.php?f=3&t=13177&p=209101
Paul

Image

User avatar
sydney
Posts: 2430
Joined: Wed May 18, 2005 9:09 am
Location: Newcastle upon Tyne
Contact:

Re: what's the use of Mode 0

Post by sydney » Thu Aug 15, 2019 7:29 am

80 column teletext rang a bell so I googled it and it guess where it pointed me?

Here

EDIT: Damn! DutchAcorn beat me to it! And my link didn't work!
Last edited by sydney on Thu Aug 15, 2019 7:31 am, edited 2 times in total.

User avatar
jonb
Posts: 2544
Joined: Sat May 21, 2011 12:42 pm
Location: South Coast of England
Contact:

Re: what's the use of Mode 0

Post by jonb » Thu Aug 15, 2019 8:22 am

1024MAK wrote:
Wed Aug 14, 2019 6:47 pm

Oh Jon, you’re spoiled the fun by coming out with a very sensible and logical answer #-o
That'll be a first, then.

:lol:

Post Reply