Upgrading A500+ MB to 2MB ChipRam

[TheCorfiot]

Hi Guys

I would like to add the 8 Ram chips and associated components onto my Rev8 500+ MB to increase the machine to 2MB Stock

Does anyone have details concerning this mod / upgrade,

I have an A501 with 4 Ram chips in sockets, just need to find another 4, does anyone know where they can be obtained from?

Of course I will be soldering sockets to the mainboard, need a BOM and jumper / track change details.

All info would be appreciated.

[jrom]

You could also look for a A500+ KCS powerboard and use that for chipmen... I happen to find one for €5,-

[alexh]

Would it not just be cheaper and safer to buy an A501+?

[TheCorfiot]

I've got a KCS version 1 board in my A500.

Tried the Board in my 500+ but just get a yellow screen, I was hoping for an instant 1MB chipram upgrade too.

A501+ are a bit hard to find and I find people are asking silly money for them, whereas I already have a 501 with 512KB in sockets.
My soldering skills are very competent (being an engineer) and feel confident to do the job as a challenge and for fun.

Just wonder if someone has already done it before..
Being a non production shipped configuration, Is the PCB correct or can it be done.. maybe the IC locations are there for older ramchips to still give 1MB max...

[alexh]

I have just done a bit of research and AFAIK there is no way to solder extra chips to A500+ (Rev8) motherboard for 2Mbyte RAM.

There are some Rev8 motherboards with empty spaces on the motherboard.

If you are in that group, either you only have 512Kbytes of chip RAM OR you have a larger capacity DRAM.

http://www.magrundke.de/hypertxt/wel...saddition.html

Of course you can try to make your own A501+ if you like.

[Fingerlickin_B]

Originally Posted by TheCorfiot

I've got a KCS version 1 board in my A500.

Tried the Board in my 500+ but just get a yellow screen, I was hoping for an instant 1MB chipram upgrade too.

Are you saying it works in your A500, but not in your A500+?

The A500+ has it's own onboard battery and RTC yes? If so, maybe it'll only work on the A500+ with the battery removed?

Sucks if I misunderstood and it doesn't work at all!

PZ.

[jrom]

KCS released a different model specific for the A500+ which gives 1mb chip mem... with a jumper setting it can be added to a normal A500 if i'm not mistaken. I don't think the other way around will work... else they wouldn't have released a version for the A500+ eh?

[TheCorfiot]

Do you know what Alex, The last PCB I looked at was my 500 with 512K on board and 4 empty IC Locations,

Of course my 500+ will already have the 8 positions filled duh......(1MB)
I will look, but I think you are right....This thread is now pointless and now closed sorry guys

Gosh had a Week off and gone loopy.

@fingers.
On the A500+ trapdoor expansion there is an RTC disable line (pin12).
when pin 12 is grounded as per 501 expansion... onboard RTC is disabled and the A500+ uses the one on the 501 card... thats why you can plug in a 501 into a 500+, get 512K extra chipram and the Clock does not conflict with the onboard.

My KCS gives yellow screen..... it was designed for the std A500 mind.
BTW.... My GVP HD8/A500 now runs DOS6.2 and Boots Windows 3.0..
Zetro wants some pics so I will tqke some soon.

[Fingerlickin_B]

Originally Posted by TheCorfiot

Do you know what Alex, The last PCB I looked at was my 500 with 512K on board and 4 empty IC Locations,

Of course my 500+ will already have the 8 positions filled duh......(1MB)
I will look, but I think you are right....This thread is now pointless and now closed sorry guys

Gosh had a Week off and gone loopy.

@fingers.
On the A500+ trapdoor expansion there is an RTC disable line (pin12).
when pin 12 is grounded as per 501 expansion... onboard RTC is disabled and the A500+ uses the one on the 501 card... thats why you can plug in a 501 into a 500+, get 512K extra chipram and the Clock does not conflict with the onboard.

My KCS gives yellow screen..... it was designed for the std A500 mind.
BTW.... My GVP HD8/A500 now runs DOS6.2 and Boots Windows 3.0..
Zetro wants some pics so I will tqke some soon.

Mine is working (with adaptor) in my A600 very well now, so surely A500/A500+ differences can be overcome?

6.2? Windows 3.0? GTFOH! How much memory do you have in that machine? Wow, very cool

PZ.

[TheCorfiot]

@fingers my GVP HD8 has 4MB Fastram. which using the KCSXMS driver can be configured easily... (allows soundblaster compat too).

Windows 3.0 I am running in real mode (8086 remember!!),
Which only needs 640K memory... ala KCS Board.

The Poor miggy does a good 16 colour VGA emulation using Interlace mode.. but screen update is soooooo slooooooow.. (Bitplane to VGA conversion). Not really useable with a 68000. But it looks cool.
Had no probs whatsoever with my HD partitions. the KCS drivers seemed to like the gvpscsi driver.
Will post piccies soon.

[Fingerlickin_B]

Originally Posted by TheCorfiot

The Poor miggy does a good 16 colour VGA emulation using Interlace mode.. but screen update is soooooo slooooooow.. (Bitplane to VGA conversion). Not really useable with a 68000. But it looks cool.

Same story here, but still cool to have it, aye?

Yes, pics = radness

PZ.

[jrom]

Originally Posted by TheCorfiot

but screen update is soooooo slooooooow..

That's why I only use it for a nice extra 1mb chipmem