From: Mikael Holm (mikael.holm_at_se.danskebank.com)
Date: 2003-01-28 10:40:31
Hej Ruud,
Okay, now I see what you mean...
And what I want to is to do just as CP/M is doing, use the original
8502-routines to access the command channel. This is not supported by any
CP/M service calls, with the exception of the USER function that can
execute 8502 code... But as I wrote in another message, I have no idea
about how to use this USER-service call.
About the Z80-boot ROM, is there a commented disassembly of it available
anywhere on the net? Or any disassembly of it, commented or not...
//Mikael
Hallo Mikael,
> But for me it's not an option, because I know even less about
> sending pulses over the serial cable to a drive than I know
> about CP/M... :-)
This knowledge is not needed. What I meant was that the drive cannot know
with what it is exchanging data. You also can reason the other way around:
a normal C64 and C128 don't notice that 64HDD isn't a real 1541.
Unfortunately a speedloader will as 64HDD doesn't execute 6502-ML ie. it
is a simulator, not an emulator. But the C128 CP/M uses the original 8502-
routines to address drives ie. no reprogramming of the drive. So IMHO CP/M
won't see at all that the drive it is talking to a fake drive.
Another remark: a good source is the C128's own Z80-bootROM.
--
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/ __|__
/ / |_/ Groetjes, Ruud
\ \__|_\
\___| http://Ruud.C64.org
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