| Posted By
MIRKOSOFT
on 2016-05-30
10:34:28
|  Send/Receive data from/to external device in area outside IO area (?)
Hi!
My Q was here in discusion earlier, but I downloaded SVS Map and have more specific Qs, so here they're:
IO area in 264 Series is between $FD00-$FEFF. I mean when it is IO it must see also C16 and 116.
My Q is bit complicated - for now I need to know if is possible to send or receive data from/to external device outside IO area.
I'm writing about area between $D600-$D7FF. Everybody now knows that it's in IO area of C128 and C64. Yes, I need to select area common for all computers - C128, C64, C+4, C16, C116.
I know that unexpanded C16 or 116 has 16K RAM (in case of C232 it is 32K, so also this), so here is Q: can C16 or 116 see area $D600-$D7FF also when it is not native IO? I mean not, but you're here people which knows everything about 264 scene, so better is to ask than not to be sure.
For next step I need to be sure if will be area common and using device will be universal without any changes.
Also I saw in SVS Map totally free space: $FF20-$FF3D / $FF40-$FFF5 / $FFFE-$FFFF
This is for C16 or 116 invisible ?!?!
Thank you for reply and for understanding not to ask about device (me personally know what is to give hopes and after failure feel like looser...)
Miro
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Posted By
Litwr
on 2016-05-30
12:26:09
| Re: Send/Receive data from/to external device in area outside IO area (?)
C16/116 with 16KB has the same 16 bit bus as Plus/4 so it can use the same addresses. The addresses at $ff20 and above are above 16 KB. So $fff0 at 16 KB C16 is the same as $3ff0 or $7ff0.
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Posted By
MIRKOSOFT
on 2016-05-30
12:37:28
| Re: Send/Receive data from/to external device in area outside IO area (?)
Thank you.
Really forgot CPU 16-bit addressing and identification between +4, C16, C232...
But now it is confirmed by you, so ok.
Main Q is aside, so:
Is possible to send/receive data between computer and external device also at address space outside IO area?
Thank you.
Miro
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Posted By
gerliczer
on 2016-05-30
12:57:25
| Re: Send/Receive data from/to external device in area outside IO area (?)
Forget it. The I/O area is different in the C64/C128 and the TED based machines, so you should adapt your device to the different operating environments. By the way, do you know that the C16/C116/+4 expansion port (pinout and contact pitch) is completely different than the C64/C128 one?
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Posted By
MIRKOSOFT
on 2016-05-31
10:08:06
| Re: Send/Receive data from/to external device in area outside IO area (?)
Of course, device will contain "bridge" between expansion port and device port.
Bridge is better than make C128/64 model and TED model... Device can be same, bridge will be used by computer.
Miro
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Posted By
gerliczer
on 2016-06-01
02:21:53
| Re: Send/Receive data from/to external device in area outside IO area (?)
Then put address translation/selection logic into the bridge.
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