#A500 problems
3 messages in this thread
Eric,
I can't help you because I just bought an A500 from a co-worker. But I
thought I would tag my questions on to youra and see if anyone out there
can help us both out.
The A500 I bought came with the original 1.2 ROMS, and OS. My questions
are:
1. How does one find out which rev. a motherboard is?
2. Can an early A500 be brought up to date (2.1 or 3.1 OS) if it has
an early motherboard revision?
3. Currently the A500 can only show 32 colors on screen, it does not
appear to have HAM mode!! (talk about ancient hardware!). Will I
need to upgrade the Paula, Denise and Agnise chips when (and if) I
upgrade the OS ROMS?
Good luck with your situation. I know that there is alot of life left
in these old Amigas! (At least until I can afford to buy, and they start
to produce again the A1200 or A4000)
!Que Viva la Amiga! Digital Universe at the touch of our fingertips
The answers to your A500 questions…
MA <<1. How does one find out which rev. a motherboard is?>>
You have to open the case and read the revision number off the the
motherboard. Also, you check the number of RAM chips. The rev#5 used 16
(256x1bit) RAM chips for 512K on the motherboard, while the rev#6 used
only 4 (256x4bit) RAM chips for 512K on the motherboard.
—
MA <<2. Can an early A500 be brought up to date (2.1 or 3.1 OS)>>
The A500 & A2000 use the same OS (KickStart) ROM. You purchased 3.1 OS
kits for the A500. The early KickStarts were 256K in size, while the 2.x
& 3.x KickStarts are 512K.
This leads to a slight quirk. The later revisions of the A500 & A2000
could detect either the 256K or 512K KickStart ROM and deal with them
automaticially. The earlier revisions (rev 3 & 5) couldn't detect the
512K ROM, and need a wire jumpering two pins of the ROM to get these
Amigas to recognise the 512K ROM.
—
MA <<3. Currently the A500 can only show 32 colors on screen, it does not
appear to have HAM mode!!>>
You should have HAM mode. All Amigas had HAM mode. The early Denise chips
found in the A1000 series lacked the Enhanced Half-Brite (EHB) mode.
You should be able to do:
– 16 colors Hires,
– 32 colors LoRes (normal)
– 64 colors LoRes (EHB)
– 4096 colors Lores (HAM)
—
MA <<Will I need to upgrade the Paula, Denise and Agnise chips when (and
if) I upgrade the OS ROMS?>>
No. You aren't required to upgrade the Denise or Agnus chips (there is no
Paula upgrade).
However, upgrading the Agnus to the ECS Agnus (#8372a), will allow you to
re-configure the A501 trapdoor memory as CHIP RAM (increasing CHIP memory
to a total of 1-meg). The ECS Agnus also allow you to use both NTSC & PAL
modes, switching between them using software. Plus there are several
other improvements the newer 2.x & 3.x KickStarts can access for improved
performance.
Don't bother upgrading to the ECS Denise UNTIL to upgrade to the ECS
Agnus. The ECS Denise added color limited SuperHires modes, Euro36, and
color limited VGA screenmodes.
Ron. – ("I'm not stupid, I'm not expendable, and I'm not going!"
– quote made by any low level RPG player.)
Ron, thanks for your in depth info. I will look into the previous
questions and I'll let you know what happens. Have a joyous holiday season!
!Que Viva la Amiga! Digital Universe at the touch of our fingertips