Oh, I'm such an idiot...


; BLOCK DATA
*= $C500
SETW .byte $03, $04, $00, $07, $02, $05, $01, $06


That *= was making my assembler trample all over the last few bytes of the lookup table that stored the chess piece characters ("WP", "WC" and so forth). Moving the *= up to C600 fixed the bug. It ...

I relabeled the *=$1000 to *=$9000 and *=$1500 to *=$9600.

Wait.. $1500? The version I've got (from 6502.org) uses $1580...

Yes, you are right. I too am not using the IO routines included in the program as my SBC and Sim already have the IO routines. I had moved the $1580 block down to $1500 ...

Wait.. $1500? The version I've got (from 6502.org) uses $1580...

Hi Phil,
I relabeled the *=$1000 to *=$9000 and *=$1500 to *=$9600.
I also modified the three calls to the system IO routines to match those of my Simulator:
syskin jmp $E821 ; Sim's get a key routine
syschout jmp $E824 ; Sim's chr ouput routine
syshexout jmp $E812 ; Sim's HEX byte output ...

Hi,
I'm trying to modify Microchess (Daryl Rictor's modified version) to run from ROM on my 6502 board. RAM is 32Kbytes from $0000 to $7FFF, ROM is from $C000 to FFFF (16k).

I've changed both of the assembly origin (*=) directives so MC is based at $C000, and replaced the ACIA routines with dummy ...

YEEEEEAAAAGHHH!!!!
It would appear that both of my "older" W65C02SP chips, datecode SA9942A, are faulty in one way or another. Chip #1 will boot EhBASIC, but causes rounding errors and random crashes - 2 becomes 2.002, etc.
The second chip boots EhBASIC, but instead of the normal "31743 Bytes Free ...

I tried your code on my SBC and simulator and did not have the rounding error.

Wonderful. I guess that means there's some problem with the RAM, CPU or (more likely) the RAM/ROM select equations. :-(
I'll try loading a RAM tester into the EPROM later. Hopefully it's something simple that can be ...

Did you set ibuffs also? As I recall, before I fixed that, I also got strange results.
10 A=10
20 Print A

would return a different number. Also, direct mode did the same.
>A=10
>PRINT A
20


I've just added the "STX Ibuffs" which seems to have gotten EhBASIC to run code properly (i.e. no ...

For my SBC-2 to run EhBASIC, besides setting up the I/O pointers in page $02, I had to modify the Ram_base constant to $0400 and the Ram_top constant to $7F00. (My I/O page is at $7Fxx.)

Nope - just changed the RAM_BASE and RAM_TOP constants - no dice. RAM_TOP is set to $8000, RAM_BASE is set to ...

Hi,
I've just finished building an EhBASIC ROM for my homebrew 6502 CPU card/backplane/UART system. RAM is 32Kbytes starting at $0000, ROM is 16Kbytes (27128) starting at $C000 with I/O in between.
The problem is, although EhBASIC will (sometimes) boot to the point of giving me the "Memory size ...

Hi,
I've just finished cleaning up and checking the schematics for my 6502 computer. I've uploaded them to my website, just in case anyone wants to take a look. URLs are:
CPU card : http://www.philpem.dsl.pipex.com/6502comp/6502cpu.tif
UART card: http://www.philpem.dsl.pipex.com/6502comp ...

Hi,
Has anyone managed to get Andre Fachat's "XA65" assembler to produce a binary file?
I'm trying to write an OS loader for my 6502 computer project. The catch is, I can't see how to get xa65 to produce a raw binary file as output. ATM it seems to be producing C64 PRG files.

Thanks.
Phil.

I'm still trying to figure out how to program a WesternDigital WD1770 floppy disk controller. I've got one sitting on my desk just begging to be used, but I can't find any usable source code that will drive it (pardon the pun) successfully. Yes, this chip is very similar to the other 177x-series ...

Personally, I use MAS65 by Douglas Beattie (sp?). Works like a charm. I've also written a simple preprocessor for it so I can use conditional compining, i.e. #include, #define, #ifdef, #undef, etc. Works like a charm.

Aww... Now I know why I can't get my hands on a MOS KIM-I or a Synertek SYM-I for love nor money... I've only ever seen one SYM on ebay -- it had a huge reserve (the auction hit $200 before the "Reserve Met" message appeared)...
Not to start a flamewar here, but it does seem a little "off the mark ...