Master Ram Board or Second Processors.

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rmbrowngr
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Master Ram Board or Second Processors.

Post by rmbrowngr » Tue May 22, 2018 12:17 pm

I’ve been reading for sometime about the Master Ram Board and second processors for the Elk. Both of them offer speed and memory improvements.

One thing that puts me off the MRB is the need to unsolder the CPU. I can do some soldering but I’m not the best and I don’t won’t to muck it up. The other is how much compatibility in software is there? It’s really an unknown question for me. From what I read it is so and so, but you can at least fall back to a normal Elk setting to get software running. The 3 options with the MRB are normal Elk, turbo, shadow ram.

A second processor looks really good especially for speed and options if you use the Raspberry PI based option. I believe you need also a tube silencer (to convert 5v signals to 3.3v?) and tube interface (like an AP5). For software making use of the second processor I think there is very little available. What would be interesting to know is how existing software runs when a 2nd processor is connected.

Which to go for?
Richard B

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daveejhitchins
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Re: Master Ram Board or Second Processors.

Post by daveejhitchins » Tue May 22, 2018 12:33 pm

I think the MRB support for games is variable in that if a game is written correctly, using all the official OS calls, then it should work in all three switch positions - and will probably benefit from the extra speed. Some games are just too slow on the Elk and so may benefit from the Turbo position. Most game will be either too fast, in Turbo mode, or won't work at all in Shadow mode.

But for BASIC, word processors, spreadsheets, languages etc. the turbo and shadow modes are invaluable.

I can do the cpu desoldering for you, if you want to go down that route?

Dave H :D
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ABR, ATI, AP6, MGC, AP5 . . .
For a price list, contact me at: Retro Hardware AT dave ej hitchins DOT plus DOT com

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jms2
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Re: Master Ram Board or Second Processors.

Post by jms2 » Tue May 22, 2018 4:36 pm

It's a good question, and one which Electron owners faced back in the 80s. The MRB was the winner back then because it was cheaper, easier to understand for the casual user, fitted inside the case, and offered a Turbo mode which gave some speed benefit without breaking compatibility too much. These days, however, the Pi option is probably cheaper and less hassle, and is massively more powerful. Whether you own a Plus 1 or not is an important factor, as the Tube adaptor does require one of these. Obviously this will affect the cost.

It does depend a bit on what you want to do with the machine. For general messing around, writing your own programs in BASIC etc the Pi is arguably better. For word processing (does anyone still do that with an 8 bit machine?) it doesn't make a huge difference either way. For games, the MRB offers a slight benefit in that Turbo mode will make some commercial games faster - some to the point of being unplayable. The Pi would not be compatible with commercial games at all (not even Elite, there isn't an Electron Tube version). :(

So in summary I think the advantages of the MRB in the retro world (compared to the Pi second processor) are:

1) Doesn't need a Plus 1.
2) Is an intriguing piece of retro kit in its own right.
3) Is neatly integrated into the base machine.
4) Makes some games faster.

This is quite a short list, so if you have a Plus 1 and don't mind bits of circuit board sticking out of your machine I would definitely recommend getting an ATI interface, level shifter board and a Pi over a Master RAM board.

Hope this helps! :D

RobC
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Re: Master Ram Board or Second Processors.

Post by RobC » Tue May 22, 2018 5:44 pm

rmbrowngr wrote:One thing that puts me off the MRB is the need to unsolder the CPU. I can do some soldering but I’m not the best and I don’t won’t to muck it up.
Might be worth seeing if there's a hacker/maker group near to you. If so, it's likely that someone there will have the necessary skills to desolder the CPU. It isn't that hard once you know what you're doing.
rmbrowngr wrote:For software making use of the second processor I think there is very little available.
I think this is probably true for the 6502 co-pro but with the Pi (or matchbox), you also get access to CP/M, DOS, GEM, Panos, PDP-11 and the native Pi core. Marcus (marcusjambler) has been doing sterling work testing and archiving DOS software. I've written some emulators for the native Pi core (ZX81, Jupiter Ace, PDP-11) and have plans for more. It might even be possible to get Prince of Persia running on the Electron via the Pi :D

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rmbrowngr
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Re: Master Ram Board or Second Processors.

Post by rmbrowngr » Sun May 27, 2018 3:04 pm

Just read this in the forum about replacing the ULA. viewtopic.php?f=3&t=9223&start=150

It really is fantastic. I do remember back in the 80’s still being a bit jealous of Beeb owners, but this would make up the difference and more. A much better upgrade than the MRB.
Richard B

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