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Post by mirkosoft on Jun 7, 2019 16:45:26 GMT
Ok, of course I know that RAM limitation...
Miro
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Post by mirkosoft on Jun 3, 2019 23:34:11 GMT
Hi!
Longer time ago I'm lacking some Kernal and Basic mods which I had in my older C128 directly burned into ROM. I have these ROMs also modified later in binary files and use them in emulators.
I know that title Q is bit naive, but really want to have not touched my new DCR. We all know that MMU allows to use and hide all. But: 1. how to override when is called Kernal/Basic routine from modified copy in RAM and in call it switches to bank where is visible ROM part, but really it needs modified part copied into RAM? 2. or even more stupid Q: is possible to take computer to see modified RAM copies instead untouched ROM originals?
Thank you for patience. Miro
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Post by mirkosoft on May 30, 2019 1:26:56 GMT
I have one: Commodore 1581 Disk Drive User's Guide. Status: no damaged, like new, no yellowed.
Really don't know what to want for... Maybe, if you have - like swap: TPUG Library CD (no matter of media, I want content, you can provide content by upload after arriving 1581 User's Guide to you).
Can it be? Please contact me via personal mail in profile.
Miro
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Post by mirkosoft on Apr 3, 2019 22:47:15 GMT
Z80 inside C128 has default address of PC $ffee - but only for 1st call, then is accepted only true PC of Z80. Really don't know how this did engineers 'cause default Z80 address is $0000. I think it is maybe for C128 startup routine 'cause C128 starts with active Z80, checks disk and then switches to 8502 - there it can set Z80's PC to $ffee, other way I don't know.
Else one Q is how CMD engineers overrided Z80 startup of C128 - SuperCPU128 totally replaces 8502 and Z80 is not accessible - it takes control over all - maybe there's any way...
Simply first Z80 call is possible easiest this way:
activateZ80: lda $ff00 ; pha ; store RAM config to stack sei ; disable interrupts lda #$c3 ; sta $ffee ; store JP instruction for Z80 mode start lda #<z80start ; sta $ffef ; store lo-byte address lda #>z80start ; sta $fff0 ; store hi-byte address lda #$3e ; sta $ff00 ; select RAM config for Z80 lda $d505 ; pha ; store mode to stack lda #$b0 ; sta $d505 ; set Z80 mode - this instruction deactivates 8502 and jumps by Z80 PC to $ffee
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Post by mirkosoft on Apr 3, 2019 11:58:26 GMT
This I know, also Z80 inside C128 can be activated with direct jump to entered address directly from 8502 system routine. This is the feature which is available - I mean if is there anything similar for registers. Z80 inside CP/M Cartridge works like we all know - when is activated it jumps into address inside PC, what is expected. So, I mean if C128 engineers did not something similar like C128's Z80 like jump directly to entered address, for registers.
Miro
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Post by mirkosoft on Mar 19, 2019 23:11:51 GMT
I know this way, only sometimes I need this and I always tried to do it with fast and minimal subroutines.
Miro
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Post by mirkosoft on Mar 19, 2019 11:26:15 GMT
Hi!
I want to switch to Z80 from 8502 and registers + PC exchange or better send them to Z80 and vice versa. Of course registers which can have their alternative in both CPUs, but most important is program counter (PC).
Is it possible? Or needs it to do it manually? If only manually I know that's possible to store and read all registers. But if exist any very quick way it is great.
Main problem is PC - but this can be used in program flow.
Thank you for all. Miro
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Post by mirkosoft on Jan 14, 2019 19:28:18 GMT
Hi! I have for sale two VDC chips: MOS 8563 R9B 4685 = revision 1 from C128D MOS 8568 1187 2002 = revision 2 used in C128DCR
and also German Kernal 128 from C128
All chips are from PAL machines.
We can make deal.
Please contact me via PM. Miro
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Post by mirkosoft on Jan 11, 2019 0:07:25 GMT
Hi!
When I was comparing pinout of Expansion Port between C128 and VIC20 I found that both are 44-pin connectors. Of course each pin means anything other by machine.
But Q is: Have Expansion Ports of both machine physically same size? Is possible to fit cartridge from C128 to VIC20 Expansion Port and vice versa? I mean dimensions - not use!
Thank you for each help. Miro
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Post by mirkosoft on Jan 8, 2019 2:25:29 GMT
Ok - understand I that it needs to extend lines to 27 and then use WINDOW command from Basic performing it in assembler? And for actual values + WINDOW check create IRQ?
Miro
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