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Jafa Systems Mode 7 Simulator ROM

One of the things that the Acorn Electron did not have, that it's big brother the Beeb did, was a Mode 7 or Teletext mode. This mode allowed for colourful Teletext display but took up minimal memory.

 

Having access to a Mode 7 on the Electron opened up access to lot of the BBC B software that would not otherwise run on the Elk. (Mode 7 expansion of the Elk was often coupled with the Slogger MRB, which gave a 64k mode so that even more Beeb titles would run.)

 

There were a few ways that Elk users could get around this:

 

- the Jafa Mode 7 Display Unit which was a hardware expansion that added 'full' Mode 7 functionality to the Electron. These are hard to source nowadays though.

 

- the Jafa Mode 7 ROM, which I have in my system, that uses software to simulate Mode 7 within Mode 2 on the Electron. Not as functional as the hardware solution, but pretty good!

The ROM works well, but I find screen refresh a little slow, even with the Electron running in Turbo mode on the MRB.

 

The ROM comes with built-in Prestel Terminal and understands Teletext control codes.

 

Over on the galax.xyz site there's some very useful Teletext tools, including a Graphics Generator to give you the VDU codes from your design.

 

 

 

 

example Mode 7 Simulator ROM screen

another example screen...

Acorn Electron simulated Mode 7 screen Acorn Electron simulated Mode 7 screen

In the video on the right I have a comparison between a Beeb disk running on the Elk in Mode 7 simulation, with 64k mode on the MRB and the same software running on an actual Beeb (well, BeebEm, at least). Many BBC B games ran fine on an Elk modified in such a way, but you can see in this video that it wasn't always quite right...

real Mode 7 vs. Simulated; isn't always the same :-)

AcornBanner - Acorn Electron simulated Mode 7 screen

more of what can be achieved in Simulated Mode 7 on the Elk

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creating simple graphics in Mode 7