#A500 upgrade
2 messages in this thread
A co-worker has offered to sel me her Amiga 500 for $100. It has img of
Chip ram, an external floppy (880bytes), lots of software and a printer.
My questions are:
1. This is is probably an older model with 1.2 or 1.3 ROMS. I am going
to upgrade the 2.04 ROMS of my A2000 (to 3.1). Can I put the old.2.04 ROMS
in the A500? Is there any motherboard revision I have to be wary of?
2. This A500 had been upgraded to 1 mg of chip RAM. If I can find an
old GVP A500 upgrade card with 8mg of ram, will this have any physical
impact on the installed 1/2 mb already added on (will they conflict in the
way that they are crammed in underneath the A500)?
3. I am going to find an external harddisk adapter for the A500. I
would like to place a 120 mg hard drive that is currently in the A200 (I'm
saving up for a 1.2Gb SCSI II drive!!) Can this Quantum LPS drive fit in
the harddisk adapter?
!Que Viva la Amiga! Digital Universe at the touch of our fingertips
MA <<Can I put the old.2.04 ROMS in the A500? Is there any motherboard
revision I have to be wary of?>>
Yes, you can use the 2.04 ROM from the A2000 in the A500. They both use
the same ROM.
However, the 2.04 ROM is a 512K ROM, while the older 1.2 & 1.3 were 256K
ROMs. Some early A500s (rev 3's & 5's) lacked the ability to auto-detect
the larger 512K ROM, and will crash. Connecting a wire between pins #1
and #31 of the 512K ROM fixed this problem. The later A500's (rev 6)
didn't need the wire, and needs the wire removed.
—
MA <<2. This A500 had been upgraded to 1 mg of chip RAM. If I can find an
old GVP A500 upgrade card with 8mg of ram, will this[…]
Once the A500 is upgraded to 1meg of CHIP RAM, the A501 expander becomes
permenant. The Agnus of the A500 now expects to find 512K of CHIP on the
motherboard + 512K of RAM *configured* as CHIP on the A501-buss. Remove
the A501 RAM, and the Agnus crashs.
Some 3rd party A501 cards offer both CHIP & Slow-FAST RAM, by using extra
hardware and software. However, many add their A501 Slow-FAST RAM in the
Zorro-II address area (stealing locations from the 86-pin Expansion slot).
Memory cards added through the 86-pin Expansion slot (on the left side)
are not connected to the Agnus or CHIP RAM in any way. You can use these
8-meg FAST RAM cards with the A501 expanders.
—
MA <<3. I am going to find an external harddisk adapter for the A500.
[…] Can this Quantum LPS drive fit in the harddisk adapter?>>
Depends on what external harddisk adapter your find. Most of the ones
designed for the A500 include a 'box' and mounting backet for holding a
either a 3.5" SCSI or IDE hard drive.
Ron. – ("I'm not stupid, I'm not expendable, and I'm not going!"
– quote made by any low level RPG player.)