[comp.sys.amiga.hardware] A500 Rev6 motherboard changes for 1M chip please.

stevep@galadriel.bt.co.uk (Steve Paine) (06/05/90)

Sorry, its that same question again. The magic 12 Months has passed and on
opening the A500 (thats what youre supposed to do isnt it!) I was
pleasantly surprised to see a lovely little 8372A in the Agnus chip holder.

Ok. So what do I do know?

Ive got 3M (512K CHIP, 512K internal expansion (with clock) and 2M in my A590)

As I understand it I have two choices.
	1) Do the mods to enable me to fill up the extra spaces on the motherboard and remove the internal expansion. (Do I lose the clock doing this?)
	2) Do the mods to enable the expansion to be used as CHIP and leave the spaces on the motherboard free.

Can someone tell me what to do please. I would prefer to keep the internal
expansion+clock and just convert this to chip. Is this the easiest?

	Any help, hints, ideas etc greatly appreciated.

	Cheers
			Steve Paine.

geoff@actrix.co.nz (Geoff McCaughan) (06/07/90)

In article <1990Jun5.143809.23430@galadriel.bt.co.uk> stevep@galadriel.bt.co.uk (Steve Paine) writes:
>
>Ive got 3M (512K CHIP, 512K internal expansion (with clock) and 2M in my A590)
>
>As I understand it I have two choices.
>	1) Do the mods to enable me to fill up the extra spaces on the motherboard and remove the internal expansion. (Do I lose the clock doing this?)
>	2) Do the mods to enable the expansion to be used as CHIP and leave the spaces on the motherboard free.
>
>	Any help, hints, ideas etc greatly appreciated.
>
Easiest by far is to retain the A501 and just remap it to chip. To do
this just find jumper J102, break the connection that is made and make
the other one. Also you have to break the jumper down by the A501
connector (sorry can't remember it's number). This way you have 1M chip
and a clock.

You could add the RAM and throw away the A501, but that is more
expensive and you lose the clock 8-(.

Last option is to add the RAM to the M/B _and_ retain the A501. You need
to do a hardware hack to get this to work. I'll be posting my hardware
hack to do this soon. 
-------------------------------------------------------------------------------
Geoff McCaughan        Email: geoff@actrix.co.nz  Phone: +64 3 539545 or 852101
Amiga/Hardware/Unix/Quantum Mechanics Hacker      Phax : +64 3 539567
"Anarchy: Think of it as evolution in action."            ^ NEW ZEALAND!