Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2018-01-23, 01:03

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Expanding on my previous comment, I decided to order a smaller set of cheaper boards last week, since the original order has been delayed so long. Those have arrived via express shipping. I don't have enough parts to build many at the moment, but I did assemble one GUS ROM module. The revision 2 …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2018-01-22, 16:35

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

shock__ wrote: cyclone3d/640k!enough/QBiN did your prototypes arrive yet? No sign of it yet. Canada Post has been rather irregular in recent years; sometimes parcels arrive surprisingly quickly, and other times they take months. I've been waiting over a month for a shipment of ROM module prototype …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2018-01-14, 00:23

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Regarding the Flash ROM: Do all 29F800B types work? There are BT and BB types available. Boot code sector architecture: B = bottom sector T= top sector Which one to choose? The sector organisation makes no difference for our purposes. As long as it has an access time of 70 ns or less, it should be …

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Re: TNDLPT : Tandy Sound on parallel port

Posted on 2018-01-11, 03:22

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

LPT port getting pretty crowded by now. Well, that creates another product opportunity for dreamblaster: a multi-port "LPT bus" adaptor. Basically, a small device that plugs into the PCs parallel port and provides multiple ports, to which such devices can be connected. There are a few ways to …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2018-01-04, 16:35

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

currently signs are towards wrong settings of my mainboard. Maybe not related, but I've noticed that the InterWave doesn't like having a high I/O recovery time on the ISA bus. In my case, it produced distorted MIDI playback (screeches and beeps) eventually, but I never bothered with the memory test …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2018-01-04, 00:30

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Did you plan to share the steps to reproduce the behaviour once it is confirmed? Is the official InterWave memory test reporting the problem?

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2018-01-02, 17:27

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Phreeze wrote: so we could also leave away the expensive 6€/$ / piece of DRAM ? I got some SIMMs laying around, i'll just use them then Yes, the SOJ DRAM is entirely optional. One can use a SIMM instead, or no RAM at all, if effects and GUS compatibility are not required.

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-28, 16:47

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Let's try to clear some of this up: The SOJ DRAM ICs should be FPM, 70 ns or less, 5V. EDO can likely be used without ill effect, but will provide no advantage. The SOJ DRAM ICs can be 256Kx16 (40-pin) or 1024Kx16 (42-pin). The 44-pin SOP socket is for the instrument bank ROM/flash. The sockets for …

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Re: New DreamBlaster S2 !

Posted on 2017-12-26, 20:51

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Hi, as you all know, the DreamBlaster S2 soundbank is ROM based, and cannot be updated. Just out of curiosity, is the instrument bank built into a monolithic synthesizer IC, or is it in a separate mask ROM? Is the format documented, potentially allowing the use of a customised, flash-based …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-23, 21:08

by

by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

The boards do look rather good. Is the finish really that shiny in person, or is that from the lighting? Seeing the assembly in progress only serves to convince me that the right-angled SIMM socket will get in the way of my first round of proof-of-concept boards. Having checked the measurements …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-22, 16:49

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Ok, I think I have lost some information. Is the DRAM the memory stick ? The ARGUS can use either (or both, in some combinations) type(s) of memory: 72-pin SIMM or SOJ DRAM ICs. The SOJ-DRAM-only configurations allow a maximum of 4 MiB of memory, while SIMM-based configurations allow up to the …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-22, 09:40

by

by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

The only obvious problem with that order is the lead time on the SOP-44 flash memory. If it really will take 20 weeks, I expect we'll be almost ready for the final production run by then. You'd probably get them sooner by finding them on eBay.

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-16, 08:18

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Phreeze wrote: i have problems finding the DRAM (and still that MS6308) For the MS6308, you can probably use an equivalent part, like the TDA1308, which is available at Digi-Key (part number 568-11063-1-ND). I haven't yet confirmed that it is a perfect equivalent, so substitute with caution.

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-15, 18:05

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Digi-Key does not stock either of those parts. They do have some usable DRAM in their catalogue, but one would likely have to order several hundred to convince them to order the parts from the manufacturer. For reference, Mouser does have stock, but they are not particularly inexpensive; see …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-15, 06:24

by

by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

I had the intention to source the components myself already. Just waiting for the build list to be updated with all the needed parts so I don't have to search too much. I'm not entirely sure we're talking about the same thing, so at the risk of re-stating the obvious, let me try to clarify. What …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-13, 15:17

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

I'll be able to do that and we're close to eachother. That offer might be useful for the next generation of prototypes, if you wouldn't mind sourcing your own components and assembling the board yourself. With the current batch of designs, it would be prohibitively expensive for me to order enough …

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Re: OPL2LPT

Posted on 2017-12-12, 05:54

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

Writes to the OPL2 registers are extremely slow. After you write to the address port, you need to wait for 3.3 microseconds, and after you write to the data port, you need to wait for 23 microseconds. Writing to the printer port is much faster than that, so I think it should be possible to 'hide' …

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Re: OPL2LPT

Posted on 2017-12-11, 21:15

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

in these the extra workload is non-existent Not quite; as explained previously by Jepael, there is still additional overhead in the form of parallel-port I/O operations. Essentially, to get the equivalent of one write to I/O address 388H, multiple writes to the parallel port addresses are necessary …

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Re: OPL2LPT

Posted on 2017-12-11, 05:35

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

I havent read every page of this topic yet so apologies if this has been asked, does this need a bi-directional LPT port? I'd like to run one from my Tandy 1000 EX which isnt bi-directional. If I remember correctly, the device does not require a bi-directional parallel port, and does not make use …

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Re: Newly made Gravis Ultrasound compatible cards ... what's the degree of interest?

Posted on 2017-12-07, 10:35

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by 640K!enough

in Marvin \ Sound

in Marvin \ Sound

shock__ wrote: Bad news everyone! Due to changed payment modalities on the PCB manufacturer's side things will get delayed another 3-4 days. No problem there. At least the news isn't that there was a design mistake and we'll have 15 paperweights.

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