[BBC-Micro] TUBE chip, accessing 'Parasite' side - 16Mhz 65C02S
Jonathan Graham Harston
jgh at arcade.demon.co.uk
Thu Mar 6 16:30:06 GMT 2008
> Message-ID: <BAY133-DAV16B37EE50EEA808A7527B4D6100 at phx.gbl>
"David Warrington" wrote:
> The 65C02S is manufactured by WesternDesignCentre in both PIC and PLCC
> packages and will happily clock up to 24Mhz (this data according to WDC
> themselves, even though the "paper spec" is 14Mhz, they overclock easily).
There are projects floating around the web to build 20MHz
ZX Spectrums and CP/M systems with the eZ80 :)
> If this all sounds *too easy* and not enough *fun*, one could think about
> paged memory on the CoPro rather than just a single memory map... and
> therefore run a modified BASIC with one 64K bank for program, and another
> 64K bank for variables.
Rather than two banks of 64K and trying to fiddle with BASIC to
get it to access the correct bank at the correct time, the HiBASIC
method is a lot easier - assemble BASIC to run at &B800 instead of
&8000, with a skelton MOS at &F800 and PAGE at &800. 44K of
program and variable storage.
> >> QUESTION 1: Does anyone have source code for BASIC4 or later? Note this
> >> Q is for assembler source, not a hex ROM dump.
Not for BASIC 4, but I have for BASIC 2,
http://mdfs.net/BBCBasic/BBC/Basic2.src Gimme a chance and I'll
get around to BASIC IV at some time.
> I think ANYONE still using a beeb today should just "drop in a 65C02" or
> "65C02S" into their beeb to allow them to use BASIC4 and the "65Cxx"
Fine until you try to run a machine code program that relies on
the idosyncrcies of the 6502's undefined instructions.
> machine code instructions. However, the OS remains the same "old" 6502 code.
> If this could be upgraded to 65C02 code, it would be more efficient (less
What about the Master Emulation ROM, see
> >> QUESTION 3: Does anyone have source code for B32K OS1.20? Or Master
What's B32K OS1.20 ?
> >> OS3.20? Note this Q is for assembler source, not a hex ROM dump.
J.G.Harston - jgh at arcade.demon.co.uk - mdfs.net/User/JGH
The most perfect world is an imperfect world as the imperfections
give people a reason to strive to change it.
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