Mk1 memory expansion

Does anyone have an interest in hardware upgrades to Mk 1 players to expand the memory, as a service?

I was talking to Mark Lord at the empeg meet and he is inclined to work on a special Mk1 HiJack kernel which would allow Mk 1 owners with extra memory to be able to access the RAM. Currently, the standard kernel would not recognise any extra installed memory.

I would propose a fixed-price modification done here by me (price to be investigated), with testing and an upgraded kernel installation.

If anyone would be interested in this, please get in touch with me either off-line at [email protected] or PM me through the board.

Not to be too presumptuous, and not that I would necessarily avail myself of said services, but would the same be possible for the other Marks 2 and 2a, as well?

Not having a Mk1 to look at, but IIRC, adding memory to a Mk1 is a fairly standard SMT solder job - either a pull&replace or an addition to existing free pads. The Mk2/Mk2a would need the new memory to be piggybacked onto the old memory chip(s), and then an address line run direct to the CPU. I doubt that anyone would want to provide that service - too tricky and risky.

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I doubt that anyone would want to provide that service - too tricky and risky.

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I don't know about that. I'm always up for a challenge. I knew about the piggybacking part, but didn't know about adding any address lines. Interesting. . .

Stu

Did I forget to mention that the CPU is BGA?

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Did I forget to mention that the CPU is BGA?

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BGA? Not on mine. There may well be a BGA version of the StrongArm CPU out there, but that's not it.

Stu

Hmm. I was being confused about that. I could have sworn it was until you just pointed it out. But thinking about it from when I had my player apart the other day, I'm sure that you're right.

Wonder what pitch it is?

There may well be a BGA version of the StrongArm CPU out there

There is. We use it in the Central. It's very small.

The mk1 has some spare pads on the other side of the board.

The mk2/2a require piggy backing onto the existing chips, and running some address wires back to the CPU.

I've had a reasonable number of responses on this, so I'll be looking into this and will post again when I have some more info for you.

Would the memory upgrade provide the MK1 with the same amount of memory as in the MK2a (16mb) or would even more memory be possible ?

I would guess the easy answer would be a 2a - 16MB. If there are an equal number of pads available to hold the chips, I would guess that you would double your existing memory from 8->16. But, if you replace the chips, it might be possible to put a different chip type in place. I think this would be a much more difficult upgrade, though.

The main problem is addressing. If there are no address lines, that leads to piggy-backs to connect the CPU to the chip selects on the memory chips. In this case, there are a second set of pads on the back of the board. Decoupling caps and pull-ups are already in place, all you need to do is add chips, giving 16 Mb. This means that the Mk1 can keep pace with larger databases resulting from newer, bigger disks.

Putting chips with a larger address range in place of the originals was possible, but the majority of the chips that could have been used are now obsolete and unavailable. Even the original memory chips are in short supply.

As soon as I can source a supply I'll be trying this out on my own player (# 15, if this makes you think about how seriously I am taking this) and I'll let you know more.

I'm also interested in this for my mk1 #129. Thanks for the idea, i wish you luck in expanding your mk1.

I have literally thousands of suitable RAM chips. I thought I've given you some for Mk2 (not Mk2a) bad RAM chip replacement?

All it needs is a kernel tweak to check for extra ram and then map it - early, before the MMU is programmed. The player won't necessarily recognise the extra memory though, but this is something that could be put in a future release.

Hugo

I would definitely be interested in this, if only so that I won't be left out of the V3 fun......

Cheers
Steve