Electron +Plus 1 + AP5 + MMFS question(s)

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dominicbeesley
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Electron +Plus 1 + AP5 + MMFS question(s)

Post by dominicbeesley » Fri Jul 13, 2018 5:53 pm

I've just got an AP5 for my Electron...I wish I could have afforded this and a floppy drive when I was younger! Rather than bombard Dave with questions I thought I'd ask here.

I've fitted the Plus 1 expansion ROM from here: viewtopic.php?f=3&t=6280&p=59926#p59926 - I put the 16K version in the ROM13 slot on the AP5

Everything worked as expected - but not much to test without a disk....

Then I then fitted MMFS v1.38 (U/EMMFS.rom) in ROM0/2

When I first power up I can access the MMFS and it boots into BASIC, I can load programs and run them. However, after pressing Break or CTRL Break, I get Language? Is this a known issue or is there something up?

Should I remove the Plus 1 rom from the actual plus 1?

D

PS: I've not fitted any jumpers so the AP5 is in Mode 0

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Elminster
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by Elminster » Fri Jul 13, 2018 7:38 pm

Not an answer but i usually get similar effects when using GoSDC in combination with AP5&AP6. On my list of things to look at, or maybe show people at Abug Cambridge (that list is getting quite long as well!)

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jgharston
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by jgharston » Fri Jul 13, 2018 10:36 pm

You could get that effect if something tramples on the ROM Manager workspace in page D. I've had a quick look through the MMCFS code on GitHub and nothing leaps out.

Code: Select all

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

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1024MAK
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by 1024MAK » Sat Jul 14, 2018 6:55 am

It's well worth while reading the Acorn Electron Expansion Application Note. Especially the bit about using ROMs. The Plus 1 ROM is ROM 12 (decimal). Note that the ROM socket on the Plus 1 PCB is not wired up so that a standard EPROM can be used. An alteration is needed if you want to fit a device that contains more memory.

Mark

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hoglet
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by hoglet » Sat Jul 14, 2018 7:09 am

dominicbeesley wrote:
Fri Jul 13, 2018 5:53 pm
When I first power up I can access the MMFS and it boots into BASIC, I can load programs and run them. However, after pressing Break or CTRL Break, I get Language? Is this a known issue or is there something up?
I've had a fair amount of use of MMFS and the AP1/6 ROM, and not had any problems like this.

MMFS does not make any use of page &Dxx, so shouldn't conflict with the AP1/6 ROM.

Can you be a bit more specific about the programs you are running?

For example, does just saving and re-loading a short basic program trigger this behaviour?

If you can post an .ssd of a program that triggers this, and post the output of *ROMS I'll try and reproduce this.

Dave
Last edited by hoglet on Sat Jul 14, 2018 7:10 am, edited 1 time in total.

dominicbeesley
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by dominicbeesley » Sat Jul 14, 2018 9:52 am

Thanks for all the hints,

The problem only presented after a re-boot. After a lot of ROM-swapping I finally tried popping the original Plus 1 ROM altogether and fitted just the JGH/RH Plus One ROM in the AP5 (socket 13) and then everything seemed to work fine.

So, to answer my own question: Yes, it seems the you need to remove the original Plus 1 ROM!(?)
I'm guessing that something in the original plus 1 rom tramples on the lock/unlock status area of the enhanced plus 1 ROM?

I didn't get much chance to test it in anger, I put a few SSDs onto my MMC but didn't get any games to work...though of the ones I looked at they all seemed to be set up for a DFS running at E00.

I was then politely but firmly reminded that we are moving house and that it might be appropriate to start putting things into boxes instead of taking them out.

D

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jgharston
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by jgharston » Sat Jul 14, 2018 11:39 am

If you have two different Plus1 support ROMs plugged in you will get problems, as they'll be fighting each other.

Code: Select all

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

dominicbeesley
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by dominicbeesley » Mon Jul 16, 2018 2:00 pm

Yes, thanks. I should have looked at the sourcecode first! I wasn't clear whether this was a "replacement support rom" for the plus 1 or a "support rom" for the plus 1 rom (i.e. in addition).

D

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1024MAK
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Re: Electron +Plus 1 + AP5 + MMFS question(s)

Post by 1024MAK » Mon Jul 16, 2018 3:10 pm

Information on the ROM and the ROM socket inside the Plus 1 here.

Mark

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