A601 1/2 meg expansion question.

[DoogUK]

Hi, i have an A601 ram expansion for the a600, its only half meg but contains the same 2 memory chips inside that the bboah a601 1 meg version contains.

Does anyone know if they made a half meg version and if so can it be upgraded to the full 1 meg?

[TheCorfiot]

Originally Posted by DoogUK

Hi, i have an A601 ram expansion for the a600, its only half meg but contains the same 2 memory chips inside that the bboah a601 1 meg version contains.

Does anyone know if they made a half meg version and if so can it be upgraded to the full 1 meg?

Hi Doog I've got an A601 on my A600 too, It has the 2 chips as you describe & the same card shown on BBoAH.

Are you saying it's 512KB because the A600 is reporting that back to you?
Check the Jumpers at the edge of the card are set correctly for 1MB, why it supports 512KB I have no idea I found this odd too.

But the Card is already 1MB, exactly the same chips & number of as fitted onto the A600 MoBo,,, which as you know is 1MB chip

Cheers Mate


Update Set the Jumpers as shown on BBoAH, from left to right jumper 2-3 & 5-6
TC

[alexh]

I've never known a 512Kbyte trapdoor RAM expansion for the A600.

[TheCorfiot]

Originally Posted by alexh

I've never known a 512Kbyte trapdoor RAM expansion for the A600.

@Alex

I know mate but for some reason the A601 has jumpers to select either 512KB or 1MB Chip ???????

Maybe C+ were planning variants of the A600, but never got round to it as usual,

If you can shed some light pls do ????

Thx

TC

[Zetr0]

hmmm is it possible that workbench is eating half a meg on startup ?

post us an image or the details of the "avail" command output in cli that will tell us if there is an issue with the chip ram.

[DoogUK]

Setting jumpers at 1 meg its still reporting half a meg....and if i boot clean with the wb 2.1 install disk or wb disk....avail is around 1.35 meg.

I must add this a601 doesnt have the RTC in it either.

[TheCorfiot]

mmmm Doog it does sound strange, I thought they all came with the RTC, has it been modified can you if extra soldering has been carried out,

You know my next request, Piccies, lets have a lookie....

My A600+A601 reports around 1.8MB+, from a std WB partition.

TC

[DoogUK]

There's components missing in comparison to the bboah pics but i assume this may be to do with the RTC missing, but from the looks of it its untouched by hackery pockery.....i'll take a pic.

[DoogUK]

Ok..here comes the pron

[Merlin]

It's down to jumper settings, the A601 could be set for 0.5 Meg. Move the jumpers onto the other pins, i.e. 1-2 becomes 2-3 on both sets of jumpers then you should get 1 Meg.

It's definitely a combination of the jumper settings.

[TheCorfiot]

Originally Posted by Merlin

It's down to jumper settings, the A601 could be set for 0.5 Meg. Move the jumpers onto the other pins, i.e. 1-2 becomes 2-3 on both sets of jumpers then you should get 1 Meg.

It's definitely a combination of the jumper settings.

@Merlin

I've already echoed the settings on my A601 to Doog, but it's a good idea to try all combinations to be sure,

Something is not quite right here, The chips are right & should be 1MB total

TC

[DoogUK]

I've tried the jumper settings..it's the same result each time.

<Baffled look>

[TheCorfiot]

Doog I've spent ages looking at your pix & the BBoAH Hires pix to follow the tracking, The resistors missing at the top all relate to the RTC,
Your jumpers in the pic by the way are defnitly wrong need to put them both in the opposite position & keep them there.

If you have a meter try continuity checks between the A601 & the A600 Mobo to ensure the socket & edge connector are making good contact, I know this may sound like clutching at straws but I can't see anything missing,
Serious MindF**K this one mate.

I'm beginning to wonder If one of the RAM chips are dead

Where's the bearded one hiding when you need him????

TC

Edit.......Woah Just noticed on your pic, Is it me or is that bottom chip looking "Brown" by the middle of the bottom row of lettering ?????

[DoogUK]

It is indeed brown an i've noticed that its seated at an angle as opposed to straight.

I'm going to desolder it and add a new chip from a pci graphics card...see if that solves the problem.

[Zetr0]

sorry guys... running slow today....

head flu working its dark mojo, even the wifie has it now bless her...

@DougUK

if you need a couple of chips i can pop 'em in the post with the 80mhz osc for you.

[TheCorfiot]

Doog
& the Manufacture date of the chip is quite different too compared with the other, Not impossible to happen but ?????? you know batch manufacturing.

As for replacing it, You took the words out of my mouth....

Good luck, Don't burn your finger & do let us know Doogster...........

TC

[DoogUK]

Thanks for the offer but i think i have a couple here off an old pci graphics card...the chips are marked hy514260b and are 60 ns....would these be ok oh bearded one?

[Zetr0]

Oh yes, they will be fine my friend

[DoogUK]

Cool! <fires up the soldering iron>

[TheCorfiot]

Hey Zed...........Good to see you mate.


Bad news you still got the headcold man!!!!! & you've infected the Mrs

That will teach you to go skinnydipping during British summertime.

TC