RE: jeri's board - SCPU?

From: Professor Dredd (
Date: 2001-03-13 13:10:44


I must ask you to clarify whether you mean 65c02 or
6502. Its an important distinction because the 65c02
has an extended instruction set and the JMP ($xxxx)
bug fixed.

It is my understanding that Jeri is emulating a 6502
using a VHDL core and tacking on the logic necessary
to emulate the 6510 on-board I/O register and extended
DMA. Thus what we end up with is an emulated 6510 NOT

It will be important to know this the first time you
try to BRA  ;-)

--- wrote:
> my two-cents worth....
> The enhanced graphics means that there is a lot more
> data to shuffle
> around... this necessitates faster disk access (ie
> JiffyDOS, parallel,
> harddisks, etc) and faster memory calcs and
> transfers (ie faster CPU).  For
> the target price of approx US$100 for a Video and
> speed enhancer, I'd be
> happy to put my hand up, but if it meant having to
> buy a SuperCPU to
> actually make the enhanced video usable, then the
> "package" would be out of
> my price range...
> The compromise is perhaps to detect the SCPU and use
> it instead of the
> on-board 65C02 - but only Jeri can tell us how hard
> that is to do. With a
> bit of discipline programmers of the new card could
> stick to 65C02 op-codes,
> something which would work on both for future
> program. As for existing
> generation software which has gone the 65816 path,
> those on smaller budgets
> would have to miss out....
> - Nick
> The contents of this email (including any
> attachments) may be
> privileged and confidential. Any unauthorised use of
> the contents
> is expressly prohibited. If you have received this
> email in error,
> please advise us immediately (you can contact us by
> telephone
> on +61 8 9441 2311 by reverse charge) and then
> permanently
> delete this email together with any attachments. We
> appreciate
> your co-operation.
> Whilst Orbital endeavours to take reasonable care to
> ensure
> that this email and any attachments are free from
> viruses or other
> defects, Orbital does not represent or warrant that
> such is explicitly
> the case
> (C) 2000: Orbital Engine Company (Australia) PTY LTD
> and its
> affiliates
> -
> This message was sent through the cbm-hackers
> mailing list.
> To unsubscribe: echo unsubscribe | mail

Get a FREE 6Mb webmail box from go6502! -

As low as 2.99% Intro APR from NextCard! -

PayPal is the FAST FREE and SECURE way to send money! -

Do You Yahoo!?
Yahoo! Auctions - Buy the things you want at great prices.
This message was sent through the cbm-hackers mailing list.
To unsubscribe: echo unsubscribe | mail

Archive generated by hypermail 2.1.1.