Explanation of how the MegaROM in the BBC Master is organised and can be customised with your own sideways ROMs, as well as a review of the RetroClinic and IFEL MultiOS boards.
Awesome content, this is exactly what I needed. I've had a RetroClinic MultiOS for a few weeks now and I'm finally getting around to customizing it, mostly so I can have MMFS built in and use the OS 1.2 and OS 3.x versions and ditch the separate 3.x ROM, and gain access to it in OS 1.2. Thanks for making this video, it explains everything quite clearly.
I have had the Retro Clinic multirom for awhile can attest it's a no brainer. Basically with the 1.20 O/S you can have a 99.9% compatible regular Beeb inside of your master which is great for games compatibility etc
Great video with good precise explanations! I have the RetroClinic MultiOS rom in my Master, but have not yet modified it. Your video will greatly help me doing that!
Man, I absolutely LOVE this video! Got to be the most useful video for the Master I've seen in a long time. I've got a MultiOS from RetroClinic and I don't have any of the gear to modify the contents. There's a lot of software in the ROMs I just don't access or need. I don't need any of the office software. I've also got a DataCentre External from RetroClinic and it's the single most amazing piece of hardware I've bought for it. I see you've got a PiTube as well - love mine. Think the only thing I need to get now is the Video NuLA for the extra colors.
Another quality vid there. I have the RetroC Multi OS. I may have a go at this a some point although buying another more modern programmer might be pain for a one off job. Is there any one who likely could do this for me if I sent off my flash ROM to them? Incidentally my Bulletin Board the Night Owl BBS is up most evenings if you are interested in checking it out .. details are on Stardot (Communcations area). I have created a frame for your channel and some other retro computer ones on the BBS. You can access with a modern viewdata client on TCP/IP on some nights you can also use dialup. The Board will be fully live quite soon. Keep the vidz coming, they are top notch.
Probably a lot of people would help you out with programming it as it's pretty straightforward and quick. The main issue is you often make a mistake or want to tweak something and sending it back and forth in the post would be a pain. It may be worth asking on Stardot, though, to see if there's anyone close by you who you could visit or borrow the programmer from.
That HDMI output on the back of your Master - where's that coming from please? If it's coming from the Pi on the PiTube - how is it set up and how is it used? I've got a PiTube in mine and know nothing of getting HDMI output from it.
The end of my video on the ARM assembly version of 3D 10 PRINT goes over this briefly: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-AhAzVnUva-k.html (link to the right bit). Basically, the PiTubeDirect software implements a frame buffer, usable from the 6502 and ARM co processors, which allows you use the Pi for output. It comes with a VDU driver so standard operating system legal software will run (and give you blazingly fast graphics and higher resolutions).
I also make a mega ROM board that is a hybrid of the two boards, 4 images and an external switch like the Retroclinic one, but smaller and not blocking the other sockets more like the IFEL version
Yes, the Master 128 is 6502 based. Because the 6502 only has a 64K memory map, 16K sections of code are 'paged' in as needed. While they are stored in many locations in the megarom and it's replacements, when the code is called it still all appears to be at the same location in the memory map (0x8000) thanks to that paging. The code itself doesn't have to deal with relocation.
Back in the olden days, I didn't have much interest in The Master... it was a bit too much of a word processing and spreadsheet machine for my liking. Watching your videos, I'm now finding out all the things I missed out on by being far too snobby.
Whenever I tell people I have a Master, nearly everyone says "is that the one with the numeric keypad". Maybe the most obvious, but probably the least useful and interesting thing about it!
Nice content! Wondering if any custom PCBs may help for any customisation content? Would love to supply free and reach any YT collab if there's a chance! (PCBWay zoey)
