[comp.sys.amiga.hardware] A500 chipmem expansion

hakanl@lulea.telesoft.se (H}kan Lennest}l) (04/07/91)

I am not reading this newsgroup on a regular bases so these questions may have
been asked before...

I have an A500 rev. 6A with fatter agnus and a Supra A501 type memory
expansion.

1. What do I need to do to install an additional 512 Kb of chipmem on the
   motherboard? Is it enough just to mount four new memory chips ?
   Are there any strappings I have to change?

2. Does the chipmem upgrade conflict with the A501 board?

3. Is it possible to use the A501 board as chipmem expansion?

Thanks.

  o           o
/Hakan Lennestal

colas@lemur.inria.fr (Colas Nahaboo) (04/08/91)

In article <3642@lulea.telesoft.se>, hakanl@lulea.telesoft.se (H}kan Lennest}l)
writes:
> I am not reading this newsgroup on a regular bases so these questions may
> have
> been asked before...
> 
> I have an A500 rev. 6A with fatter agnus and a Supra A501 type memory
> expansion.
> 
> 1. What do I need to do to install an additional 512 Kb of chipmem on the
>    motherboard? Is it enough just to mount four new memory chips ?
>    Are there any strappings I have to change?
> 
> 2. Does the chipmem upgrade conflict with the A501 board?

yes. If you go this way you won't be able to have a clock.

> 3. Is it possible to use the A501 board as chipmem expansion?

Yes, and this is the best way since the A501 runs twice as slow as fast ram, it
is erally better used as chip ram.

- find jumper JP2 (up-left of 68000) up and middle plots are connected, you  
  must cut this and connect middle to low.

- find jumper JP7A (near A501 connector), and totally open it. (up and middle 
  were connected)

that's it!! no trace to cut, easily reversible...
This will work with any 512K trapdoor ram expansion to the 500.
My 500 has now 1 Mega of chip ram, and works perfectly...

-- 
Colas Nahaboo, colas@sa.inria.fr, Bull Research, Koala Project, GWM X11 WM
Phone:(33) 93.65.77.70(.66 Fax), INRIA, B.P.109 - 06561 Valbonne Cedex, FRANCE.

hessu@clinet.fi (Tapio Heiskanen) (04/10/91)

From article <3642@lulea.telesoft.se>, by hakanl@lulea.telesoft.se (H}kan Lennest}l):

> I have an A500 rev. 6A with fatter agnus and a Supra A501 type memory
> expansion.
> 
> 1. What do I need to do to install an additional 512 Kb of chipmem on the
>    motherboard? Is it enough just to mount four new memory chips ?
>    Are there any strappings I have to change?
> 
> 2. Does the chipmem upgrade conflict with the A501 board?
> 
> 3. Is it possible to use the A501 board as chipmem expansion?

I'd like to know how to do this, too. :-)

Thanks in advance...


-- 
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