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| | Previous Messages | Posted By
gpz
on 2025-05-19
18:44:39
|  Re: "Speedy" cartridge info wanted
I just realize that doesn't really say much, because you can do the same by just loading the cart  But its not that, its really running far enough to show that screen - except the emu doesn't actually show it, because it can't fetch screen memory from cartridge... yet  |
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Posted By
gpz
on 2025-05-19
18:40:38
| Re: "Speedy" cartridge info wanted
some progress
Displaying 40x25 screen at $9c00:
*C:9c00
*C:9c28
*C:9c50
*C:9c78 speedy 16
*C:9ca0
*C:9cc8
*C:9cf0 (c) 1988 H.a..?.M
*C:9d18 a.HL..-
*C:9d40 programmed by pirx
*C:9d68
*C:9d90
*C:9db8
*C:9de0 t0800 0fff 4000 H.a.....>.Lf."p..
*C:9e08
*C:9e30
*C:9e58
*C:9e80
*C:9ea8
*C:9ed0 UCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCI
*C:9ef8 Bf1 - tape f2 - disk f3 - exitB
*C:9f20 JCCCCCCI UCCCCCCK
*C:9f48 Bhelp - clear memoryB
*C:9f70 JCCCCCCCCCCCCCCCCCCCK
*C:9f98
*C:9fc0
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Posted By
Patrick
on 2025-05-18
15:40:19
| Re: "Speedy" cartridge info wanted
i think that Chris Snowden was behind the hardware shop or atleast he will know who it was! |
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Posted By
gerliczer
on 2025-05-18
04:21:21
| Re: "Speedy" cartridge info wanted
Assuming the theory of operation deduced by Bionic in that topic I mentioned earlier is correct, I can imagine it somehow working. As the ROM is 8 kB only, it will naturally wrap around its address space so it will properly fit into a 16 kB ROM slot twice. If it actually manages to redirect IRQ vector access to $FDFE/$FDFF it will jump to $FD10. Further assuming it can actually run the code from there, it will continue executing the ROM code which then jumps to $FDF4, where it pages itself into the memory space at its intended address of C1Low ($FDD2 = C1L+KERNAL) then transfers control to itself.
About the question of existence. The source explicitly says that the schematic was reverse engineered. That, as far as I understand English, means an actual existing hardware item was examined and the result of those efforts were documented. The hardware shop at www.commodore16.com intended to sell a replica of this built on that same information. Maybe you could try contacting the guys who were running that operation and talk to them about what they remember. As far as I could dig things up, Patrick and retroscener were probably active there in the forums. There should be some chance they could guide you to the people behind the shop. |
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Posted By
gpz
on 2025-05-17
19:17:28
| Re: "Speedy" cartridge info wanted
First - please lets not get into discussing how useless this cartridge is or how pointless it is in emulation - i am well aware of that For choosing which cartridges to include in VICE, all that matters is that they existed "in the wild" (usually with a loose definition of "3 copies" - if this was really a prototype and noone actually had one we can stop right here - but do we actually know this is the case?).
I am just looking at it (again) because it is the last cartridge type we do not emulate yet - and because it is so obscurely implemented, which is always a challenge to make work in the emulator.
That said, i also believe that those schematics are not 100% correct - i can tell what it wants to do in principle, but when looking at the details, some things don't match up. Hence the question for someone who owns this or at least has seen it maybe
And then there is the ROM dump... which doesn't make sense to me either, when trying to match it against the supposed/guessed working of the hardware (but this might be easier to figure out for someone who is more familiar with the plus4 ROMs and banking things) |
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Posted By
BSZ
on 2025-05-17
06:41:36
| Re: "Speedy" cartridge info wanted
I don't think it's a finished, stable piece of hardware. It is likely that a prototype circuit may be reverse-engineered, and it may not be a flawless/complete drawing. If it worked, it would probably be a common card, but we haven't even met anyone who has seen one.
But looking at the schematic, I'd be afraid to even try it. (We have seen too many dead CPUs/TEDs already.  )
Let me write a completely personal opinion: emulation-wise, this hardware is completely irrelevant. Even if it worked, you have much more and better options under an emulator than with any limited hardware. Few hardware extensions were used on plus/4 in the past. This is perhaps due to the fact that there is a usable (even if not flawless) machine code monitor in KERNAL, and BASIC also contains the commands needed for basic disk handling. These mean that for basic use, there is really no need for extra extensions. Of course we were envious of the C64 freeze cards, but the interesting features are not possible on plus/4, and of the system software extensions, only the turbos would have been interesting, the rest is available about natively.
In summary, I think you should forget about this circuit. If ROM BANK logic emulation works, cards with simple ROM expansion will work. 1 |
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Posted By
gpz
on 2025-05-16
09:04:54
| Re: "Speedy" cartridge info wanted
Yeah, stumbled about that before - unfortunately not much info there either |
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Posted By
gerliczer
on 2025-05-15
13:52:01
| Re: "Speedy" cartridge info wanted
There was a discussion about it here in the forum ages ago. See here. The guys are referring to it simply as 'freezer'. |
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Posted By
gpz
on 2025-05-15
09:27:23
| "Speedy" cartridge info wanted
Hy ppl!
Once again i am looking at cartridge related things in VICE - and one that is still open for xplus4 is "Speedy". This seems to be a relatively obscure "Freezer" type of cartridge (very unlike other existing +4 cartridges). What's a bit baffling is, that everything you can find about it is a copy (or the original source) of these two files:
https://www.zimmers.net/anonftp/pub/cbm/schematics/cartridges/plus4/index.html
So mmh... some questions remain. Does anyone have ever seen this cartridge for real and can tell more? Perhaps even still owns it (a clean ROM dump would be super nice, the existing one looks strange). Also, could someone who is more familiar with +4 hardware look at that schematic, and try to make sense of it? I am pretty sure it contains errors in a detail here and there - but someone who is more into +4 can probably tell what it *wants* to do (and what the schematic should really look like). |
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