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Picked up 1040STf, need some cheap accessories


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Partial credit!

 

With TOS 2.05 or later, or MagiC (and presumably FreeMiNT) - from what I can dredge up - these boards supplement the MMU in the ST adding up to an extra 12MB.

 

I found this on the Sound on Sound Atari pages: "Even though the ST's memory-management unit (MMU) can actually only handle 4Mb, the Magnum card supplements this, working in tandem with the ST's MMU to access the full 16Mb."

 

Your Amiga analogy is bob-on. ST-RAM is like ChipRAM, in that the chipset and CPU need access to it because all the I/O is memory mapped there, the Video Shifter needs access to it to generate the display... so there's bus contention. TT-RAM is like FastRAM - the chipset doesn't need to access it so the CPU doesn't need to worry about being locked out of accessing it.

 

So, I don't think games and TOS binaries will be able to see the extra memory, but after the installation of the driver to access the new MMU, I'm guessing it just gets mapped into the free memory pool - providing there's OS support.

 

That's awesome then. I wonder if SuperTOS improves the process as well.

 

I only used that Amiga-ism since it's commonly known. I was a loyal ST'er back in the day, from the 1040STf to the Falcon.

 

Now as for ST RAM, I'd imagine only 14MB (or less) is usable. After all, that's the limit of the Falcon with 16MB EDO installed for ST RAM. I'd love to see a program that could recover that extra 2MB for a RAM Disk or something else. Similarly, I've read there are similar programs for 32-bit WinXP for the leftover unused 500MB above 3.5GB when you have 4GB installed.

 

I'm surprised there aren't other exotic steps, like separate RAM for TOS on TOS adapter boards. Sorta like the exotic bank switching steps available on A8. I was pondering last night if it were possible to place the graphics chips on a separate board and add VRAM to it if that would be possible with a proper TOS driver.

 

I suppose with an FPGA emulating the MMU with some added code, the RAM could be expanded to the limit of the 680x0 series, again also with the right driver.

 

Thanks for the info!

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The PAK 68/3 accelerator for the ST had an optional FRAK board which could hold additional memory, but it probably uses the 68030's MMU and may appear as TT-RAM? I regularly emulate a TOS 2.06 STe with 14MB ST-RAM without (m)any issues. The CT60 accelerator for the F030 can add an additional 512MB apparently, but that has a 68060. I would never do that to a Falcon... it's cheating!

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The PAK 68/3 accelerator for the ST had an optional FRAK board which could hold additional memory, but it probably uses the 68030's MMU and may appear as TT-RAM? I regularly emulate a TOS 2.06 STe with 14MB ST-RAM without (m)any issues. The CT60 accelerator for the F030 can add an additional 512MB apparently, but that has a 68060. I would never do that to a Falcon... it's cheating!

 

There has to be a better way of getting TT RAM into a Falcon without resorting to the CT60 board which requires going with a external power supply mod.

 

I'm also surprised at the lack of Motorola DSP mods for all of the STs and TTs. That chip essentially would give the ST family the audio prowess it was supposed to have with the AMY chip that the Tramiels couldn't get to work. The DSP used to cost $1,000 back when the NeXT Cube debuted but it was being used in the iPod Shuffles a few years ago. Considering those are essentially disposable, the supply available for modding probably surpasses the number of working STs, STe, and TTs still around. Again, a 68000 based driver would be needed unless such an upgrade demanded a corresponding 68030 upgrade as well.

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I don't see why, the F030's 68030 sits on a 16-bit data bus, just like the 68000 in the ST...

 

Main reason would be that video in ST is based on 16-bit RAM + MMU + Glue, etc. Of course, it is possible to have 32-bit Fast RAM together with 68030, but 32-bit video would mean practically new computer, and not upgrade.

DSP as ST upgrade ? I think that it is still very expensive, and likely hard to find.

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Main reason would be that video in ST is based on 16-bit RAM + MMU + Glue, etc. Of course, it is possible to have 32-bit Fast RAM together with 68030, but 32-bit video would mean practically new computer, and not upgrade.

DSP as ST upgrade ? I think that it is still very expensive, and likely hard to find.

 

Also, where you put it? Mechanically and electrically, I mean? It might have to piggy back on the 68000, ruling out concurrent use with an accelerator board or emulator board... The cartridge port is too slow (256KB/s) and only maps into 128KB of address space. The DMA port is an obvious alternative, (1.25MB/S) but there might be issues with other devices on the bus, and hanging it outside the case it's likely pick up electrical noise, which the DSP was never designed to encounter... the data would have to packetized as well, leading to inefficiencies and overheads...

 

The simple answer is this: Atari already made an ST with a DSP chip... it's called the Falcon030! If adding a 56001 would require a 68030 as well, then you've got a Falcon without the lovely graphics, and no audio in without a sampler cartridge, which was one of the main reasons for using the DSP in the first place!

 

Could the DSP perform the functions intended of the AMY chip? I'm not sure... AMY was an additive Sine-wave synthesizer, similar in operation to the decode stage of a vocoder in how it handled PCM playback. To simulate the AMY, you'd need wavetable memory to store the amplitude of the sine wave at various points in time. I've never coded for the 56001, so for now let's assume we can set aside 128K or so for our wavetables that the DSP can DMA to, so we can poke a value directly from the table into a 56001 register. Our code needs to read the next note value... maybe the DSP matrix could speed up the translation of the note value into the relevant amplitude from the wavetable. But AMY had 64 oscillators! Once we've set up our oscillators, the DSP transform matrix could be used to sum the sine waves, that's the sort of thing it's good at...but it's 24 clocks to fetch the note value, probably another 24+4 clocks to poke that into the DSP to look up the amplitude... and if we're doing that up to 64 times for each note... I don't think it would be feasible.

 

DSPs are great for subtractive synthesis, it's a linear signal path. But additive synthesis involves multiple parallel operations, which I don't think they're great for.

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Also, where you put it? Mechanically and electrically, I mean? It might have to piggy back on the 68000, ruling out concurrent use with an accelerator board or emulator board... The cartridge port is too slow (256KB/s) and only maps into 128KB of address space. The DMA port is an obvious alternative, (1.25MB/S) but there might be issues with other devices on the bus, and hanging it outside the case it's likely pick up electrical noise, which the DSP was never designed to encounter... the data would have to packetized as well, leading to inefficiencies and overheads...

 

The simple answer is this: Atari already made an ST with a DSP chip... it's called the Falcon030! If adding a 56001 would require a 68030 as well, then you've got a Falcon without the lovely graphics, and no audio in without a sampler cartridge, which was one of the main reasons for using the DSP in the first place!

 

Could the DSP perform the functions intended of the AMY chip? I'm not sure... AMY was an additive Sine-wave synthesizer, similar in operation to the decode stage of a vocoder in how it handled PCM playback. To simulate the AMY, you'd need wavetable memory to store the amplitude of the sine wave at various points in time. I've never coded for the 56001, so for now let's assume we can set aside 128K or so for our wavetables that the DSP can DMA to, so we can poke a value directly from the table into a 56001 register. Our code needs to read the next note value... maybe the DSP matrix could speed up the translation of the note value into the relevant amplitude from the wavetable. But AMY had 64 oscillators! Once we've set up our oscillators, the DSP transform matrix could be used to sum the sine waves, that's the sort of thing it's good at...but it's 24 clocks to fetch the note value, probably another 24+4 clocks to poke that into the DSP to look up the amplitude... and if we're doing that up to 64 times for each note... I don't think it would be feasible.

 

DSPs are great for subtractive synthesis, it's a linear signal path. But additive synthesis involves multiple parallel operations, which I don't think they're great for.

 

 

I guess from your analysis, you'd have to have a piggyback board that plugged into the CPU slot/location [after desoldering] and then the board would have a spot for the 68000/68030, possibly the 68881/68882, and then the DSP. So it would have to be a new upgrade board.

 

I didn't exactly mean emulating the AMY, I meant giving the stock STs good audio to make up for the sucky YM and the fact that Atari Corp didn't get their act together and thus us original ST owners got shafted due to the lack of the AMY [or the YM2151]. If the DSP were available to all owners, we could get those interested in updating the ST gaming library to add better audio…they are already patching/correcting ST games to install to hard drives, making them compatible with later versions of TOS and compatibility with the faster 68000s and 68030s, etc. The DSP couldn't emulate the AMY but I bet it could emulate the Paula so it might be possible to grab the audio from Amiga titles and add them into the modified ST versions.

 

As for money, it would only really cost money for the board itself. As I stated before, the Motorola DSP was used in iPod Shuffles and those are a dime-a-dozen on the used market.

 

Maybe it would be a good idea to crank out a piggy back board that could install where the YM2149 is and add a YM2151 to it. Then all of the arcade conversions that featured that processor could have its audio ported. Hey, that's the plan with Curt Vendel's/Syzygy's XM Expansion Module for the 7800 console! [well that, adding the POKEY the 7800 should've came with standard, 128K RAM, and the High Score Cartridge feature that Atari Corp forgot to bring to market back then, etc.].

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Hi folks,

Sorry to chip in late, but I recently bought an Atari 1040 STf with mono monitor. I was pretty impressed by Jookie's drive unit (using a Raspberry Pi) so put in an order. Price seems reasonable considering prices of external floppy & hard drives in e-Bay. I live in Western Australia so freight is a killer. I'm also waiting on a VGA adapter for my LCD screen (mono only) and am contemplating TOS 1.04 upgrade as I can then load ST files from my PC and it's USB floppy drive.

 

I thought of trying to build my own USB stick interface but it's cheaper to buy from the techies. My hardware skills are very rudimentary. C coding is non-existent.

 

Keep up the info as I'm learning heaps. Thanks :-)

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Sorry guys, I'm re-hijacking the thread... So I'm looking into getting a GBS-82x0 so I can hook up my ST color output to VGA, but in a perfect world I'd love to get both Mono and Color to one monitor.

 

So the ST to GBS converter to VGA seems to be doable, plenty of schematics online for that setup to convert the 15khz signal to VGA, but could I also feed the same signal for mono out to the GBS? There are several sites that seem to indicate that the GBS-82x0 will accept 30khz vga input as well as 15khz ega. So will that work? (was thinking I'd get the best-electronics-ca.com dual res monitor cable and use that.

 

I suspect I'm going to have to "try it and hope", or break down and buy ST monitors, or find an old multisync vga monitor.

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Yeah, I know how it works. I have a question for you. the input options for these boards are confusing at best, I saw something somewhere that said the HD9800 also accepts 30kHz vga as an input, so if that's the case can I hook up my ST and get low/med or high mode through the same connection? The gbs-82x0 often times do not say they accept vga 30khz as an input method. Just wondering if you tried high mode with the hd9800, or if the specs are bologna?

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ST high res looks great with one of those VGA cables on NEC, Samsung, (and probably other) Multisync LCD 1280x1024 4:3 monitors. 640x400 scales to 1280x800 with black bars at the top & bottom. The multisyncs have great control over vsize, etc. which most modern monitors leave off. People around here are giving them away- no one else wants them.

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ST high res looks great with one of those VGA cables on NEC, Samsung, (and probably other) Multisync LCD 1280x1024 4:3 monitors. 640x400 scales to 1280x800 with black bars at the top & bottom. The multisyncs have great control over vsize, etc. which most modern monitors leave off. People around here are giving them away- no one else wants them.

True galax they are valuable monitors. But I'm surprised that people living in North America get rid of them. In Europe, these monitors are sold online (on ePay or anywhere else) for more than 60 Euros/$90.

Here is an example :

http://www.ebay.de/itm/Commodore-1084s-1084S-D2-/171359498857?pt=Klassische_Computer&hash=item27e5d27269

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