Hello,

I am hacking together Net and OpenBSD for the A500 (1Mb RAM). I am looking for datasheets of the CPU bus, floppy and RCA jack busses and things for programming small kernels. The meaning is to have BSD kernel better for games.

Best regards,
ghosty

@ghosty3

Not sure if these are much use to you:

Amiga Hardware Reference Manual

Technical Reference and Service Manuals for the 500 and 500+ (and lots of other goodies)

Complete Amiga 500 schematics

_________________
RobTheNerd.com | InstallerGen | SMBMounter | Atoms-X

@Daedalus

Is there any difference in an A500 of '87 or '89 (rock lobster) ?

Except for the KS ROM 1.2, 1.3.

@ghosty3

Not sure about BSD but I thought you needed a M68K CPU with an MMU to run Linux?

_________________
Amiga A1200, 3.1 ROMs, Blizzard 1230 MKIV 64MB & FPU, 4GB DoM SSD, Workbench 3.1

@ghosty3

I couldn't tell you the exact revision dates, but there were several revisions of A500 motherboard, some with significant differences. And I wouldn't trust the revisions to be perfectly aligned with things like Kickstart version either - Commodore had a habit of just using whatever parts were available, resulting in various combinations of parts in many models.

But architecturally, they should all conform to the Hardware Reference Manual, including bus timings, address map etc. The physical layout will change from revision to revision (for example, Rev. 3 & 5 had 16 32KB RAM chips, Rev. 6 & 8 had 4 128KB RAM chips with space for another 4). Some (particularly later revisions) also had newer versions of the custom chips, giving them certain ECS features that the older revisions lacked, such as 1MB Agnus, but logically they should appear pretty much identically from a software perspective.

Last edited by Daedalus on 22-Mar-2017 at 09:11 AM.

_________________
RobTheNerd.com | InstallerGen | SMBMounter | Atoms-X

@Daedalus

OK, clear to me, 8-bit busses AFAIK

Thanks a lot for the manuals

Last edited by ghosty3 on 25-Mar-2017 at 03:01 PM.