[Coco] POKEs and PEEKs in NitrOS-9?

[Bill Pierce]

Bill, in OS9, the roms for a cart are not used and have no meaning. Therefore setting the MPI to a certain slot really does nothing as this really just sets the active rom. The buss addresses for carts are accessed regardless of position of the slot switch.


For example, I have an FD-502 controller with HDBDOS rom in slot 4 (no drives, just for dw4), a MIDIPak in slot 3, and ORCH90 pak in slot 2. Under RSDOS or OS9, the Coco can send sound through the Orch90's stereo 8 bit dacs, and send MIDI bytes out the MIDIpak while the slot is set for 4


The conflict you are going to have is that if both controllers use the same address buss, OS9 will be trying to read/write to both. I have no idea what the consequences are there, but definately not good.
The 2 controllers would have to have different buss addresses. All RS controllers are the same in this respect. BUT... the Disto controllers and others may work for what you want, but you have to have drivers and descriptors for both controllers and since most all floppy descriptors are labeled "/d0", "/d1" etc, these would have to be renamed (internally and externally) for the 2nd controller.
I know there's a couple of people here on the list that have experimented with this and there may be other things to consider as well and I'm sure others will chime in....
 

Bill Pierce
"Today is a good day... I woke up" - Ritchie Havens
 

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-----Original Message-----
From: Bill <cwgordon at carolina.rr.com>
To: Coco Enthusiasts <coco at maltedmedia.com>
Sent: Mon, Dec 1, 2014 11:13 am
Subject: [Coco] POKEs and PEEKs in NitrOS-9?


Recently, while "goofing around" in an attempt to re-learn some of what I
knew about my beloved Coco 3 (512k), I discovered that with 2 disk
controllers in the MPI, while using RSDos, I could access any slot simply by
using POKE &HFF7F,X. (X being 0 for slot 1, 17 for slot 2, 34 for slot 3,
and 51 for slot 4.) I have written a test program, saved it to the drive
controlled by the controller in slot 4, did the POKE for slot 3 (34) and
saved it on the drive controlled by the controller in that slot. Works
great, and I plan to investigate further.

Now, here's my question: Can this same thing be done from NitrOS-9? Can
POKEs and PEEKs even be used in NitrOS-9?

Thanks

 


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