05 April 2017, 10:26 | #121 |
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05 April 2017, 10:32 | #122 |
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There are lot of articles about that on my site so please go there and start reading.
FPGA would die in few seconds if you connect it directly to Amiga so yes there is "protection" on each I/O that is connected to Amiga. However Vampire card on A500 don't become bus master on traditional way like on A600 using bus arbitration and those signals are not implemented because you remove MC68K from the motherboard to add V500. |
05 April 2017, 10:36 | #123 | |
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I think you have answered the question in any case. |
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05 April 2017, 10:40 | #124 |
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You have 2-wire or 3-wire bus arbitration used there. You don't need to use 3-wire bus arbitration at all, so BGACK is not needed. If you remove CPU there is no need to do bus arbitration at all so no need to implement those signals.
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05 April 2017, 10:44 | #125 |
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Erm... you do need bus arbitration. You can plug a CPU into the A500 sidecar socket. This is exactly what I am talking about. You effectively have a zorro slot on the A500 that can become a bus master by itself. You also need bus arb if you want this to work on any Atari hardware because they all use the bus arb for DMA cycles.
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05 April 2017, 10:46 | #126 |
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If you use expansion slot then yes, you need it.
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05 April 2017, 15:01 | #127 |
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05 April 2017, 15:11 | #128 |
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Indeed, not everyone is an electronic guru. I didn't know either and I do know a small bit of electronics (just enough to get small schematics designed and working, probably not always the best designs but hey, if it works that's sometimes enough). |
05 April 2017, 15:31 | #129 |
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I happen to be a microelectronics engineer. It seems, though, that the very definite term "isolated" means something very different to "plasmab". It seems he is interested in level conversion and whether it is implemented in a bidirectional way.
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05 April 2017, 15:40 | #130 | |
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Ah.. @plasmab; there are no logic level converters on the amiga. See http://www.amigawiki.de/dnl/schematics/A500_R6.pdf |
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05 April 2017, 15:44 | #131 |
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He was asking about level converters on the Vampire, not on the Amiga.
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05 April 2017, 16:26 | #132 | |
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Ah, majsta did wrote a blogpost once about it. I can't find it right now (two minions keeping me distracted a little too much ATM). Original vampire 600 (v1) schematics http://www.majsta.com/modules.php?na...pdf&MediaNum=1 Maybe that gives a hint Edit: I think the TI LVT16245's I see in the picture do the trick. They're 3.3v bus holders, but do accept 5.5v max in. Last edited by prowler; 05 April 2017 at 21:46. Reason: Back-to-back posts merged; please use the 'Edit' button. |
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11 April 2017, 02:26 | #133 |
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This thread makes me sad to post in now but now for something a bit different.
Talking to a member of the Vampire team, one of them wants to play with getting the V500 working with the CDTV ROMs. If someone has a CDTV or even an A570 that they would consider offering to the team let me know and I'll put you in touch with the person inquiring. |
11 April 2017, 07:28 | #134 | |
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Sadly I have only one CDTV, I know Sveta was offering one but I don't know if it's always available |
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20 April 2017, 01:22 | #135 |
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Just had the shipping notice for my Vampire
Now to get one of my 500's in a fit state to put it in! |
20 April 2017, 02:08 | #136 |
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20 April 2017, 02:11 | #137 |
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What's happening when a board has been "allocated" on the website (few months after I raised my interest)?
I haven't received any email from Majsta and don't want to miss my turn... Sent from my iPhone using Tapatalk |
20 April 2017, 02:13 | #138 | |
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20 April 2017, 12:51 | #139 |
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Thanks... seems I need to contact Majsta...
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20 April 2017, 18:02 | #140 |
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