Print Page - How to read/write from/to REU in assembler?

Title: How to read/write from/to REU in assembler?
Post by: MIRKOSOFT on October 11, 2009, 07:19 AM

Hi!

I have now 1541Ultimate Plus Ethernet.

In options I choose REU Enabled with size 16MB.

So, I know that it must adressed in 256 banks ($00 - $FF) to access full size of 16384 kB.

But, I don't know how to access REU in assembler, in BASIC it is easy with commands FETCH, STASH, SWAP.

So, easy question with maybe with complicated answer:

How to read/write from/to REU in assebmler?

Thanks for every reply.

Miro

Title: Re: How to read/write from/to REU in assembler?
Post by: commodorejohn on October 11, 2009, 07:49 AM

Have you been to the Zimmers.net Commodore FTP archive? (http://www.zimmers.net/anonftp/pub/cbm/index.html) There are a whole ton of manuals and books there about Commodore programming (the 1700/1750 REU manuals, for example,) which have the answers to a lot of your questions.

Title: REU - addressing 16384kB
Post by: MIRKOSOFT on October 12, 2009, 09:25 PM

Hi!

Thanks for link.
I found there manual for 17xx REU. But what I'm not sure is that I don't know how to address more than 8 banks (REU 1750 - 512kB), I selected in 1541U REU size 16384kB, so it needs $FF banks - but how to address it?

Thanks for help.

Miro

Title: Re: How to read/write from/to REU in assembler?
Post by: commodorejohn on October 12, 2009, 11:37 PM

All you need to do to access larger REUs is write the appropriate (higher) value to the bank register. Actual Commodore REUs won't recognize it, but others like the RAMLink or your emulated one will handle it just fine.

Commodore 128 Alive!

Commodore 128 => 128 programmers => Assembly => Topic started by: MIRKOSOFT on October 11, 2009, 07:19 AM