- The LaST Upgrade -

Part 46 - DFB1X 030 FALCON ACCELERATOR

Last updated February 23, 2024

The DFB1X is the exxos revised addition of the DFB1 (David's Falcon Booster MK1). It is a low cost easy to install plug-in accelerator for the Atari Falcon 030 which typically runs between 40MHz - 50MHz and uses the original PSU and fits within the Falcons case without modification. The Falcon CPU is crippled by its 16MHz speeds and its 16bit bus, while the DFB1X has 128MB of alt-ram which is accessed at the full 32bits giving a huge speed increase over a stock Falcon. The DFB1 also has a 40MHz - 50MHz FPU and 2 banks of user programmable flash ROM.

The DFB1X is a official licensed branch of the original DFB1 accelerator.

 

USER JUMPER SETTINGS

JC1 = Master clock select. Jumper open or closed will select 40MHz or 50MHz oscillator. Both CPU & FPU share the same clock. 40MHz is considered the default speed and 50MHz is the overclocking speed.
CLOSED = 40MHz
OPEN = 50MHz.

NOTE: The DFB1X is purchased as either a 40MHz or 50MHz capable board. If you purchased a 40MHz board , then the 50MHz option cannot be used.

 

BS1 = Flash ROM Bank Select.
OPEN = BANK 1
CLOSED = BANK 0

NOTE to program the flash you need to jumper the DISABLE jumper and use the flash tool.

J2 OPTION JUMPERS
OPTION = RESERVED FOR FUTURE USE

ALTRAM
OPEN = ALT-RAM ENABLBED
CLOSED = ALT-RAM DISABLED

FLASH
OPEN = FLASH ENABLED
CLOSED = FLASH DISABLED

DISABLE
OPEN = ENABLE BOOSTER & FAST CPU
CLOSED = DISABLE BOOSTER.

 

LED INDICATORS

D1 = Lit = DFB1X is active and disabled the Falcons motherboard CPU
D2 = Speed indicator. Fast CPU is active when lit. This will vary in brightness depending on bus activity.
D3 = Coprocessor activity flag - DSP.
D4 = ALT-RAM access. This will vary in brightness depending on bus activity.
D5 = FPU & RESET. FPU access will flash the LED. It will light brightly while holding the reset button.

All LEDs will flash while programming the flash ROM.

 

FIRMWARE / SOFTWARE / TOOLS

DFB1X Alpha1 June 26, 2023
DFB1X Release - June 28, 2023 - Modified LED behavior and speeded up booting to 50MHz.
DFB1X v1.03 July 3, 2023 - FPU tweaks, should improve speed and stability at 40 & 50MHz.
DFB1X V1.04 July 6, 2023 - FPU tweak, Some bugs fixed in startup and clock switching. 8MHz mode now disables the boost in SI.CPX.

FLASH UTIL (FIXED) - Drag drop a OS image file onto the TTP to program the flash. Booster must be disabled to flash. See known issues below.

MAPROM / NVDI - Current required software for TOS404.Copy all this to your boot drive. You need to use AUTOSORT and make sure the boot order is, MAPROM,WDIALOG,NVDI.

PRGFLAGS - Sets the alt-ram loader bits on PRG files.

FPU INSTRUCTION TEST - FPU RAYTRACING - ST/TTRAM TEST - GB6 BENCHMARK

DFB1 Original sources https://github.com/dh219/DFB

MAPROM GITHUB https://github.com/agranlund/tftools (NOTE I have not got the current version of MAPROM to detect the TTram , so be warned!)

 

KNOWN ISSUES

MAPROM - Some versions may not work. Please use the one listed above. MAPROM may crash when trying to enable alt-ram while the booster is in DISABLED mode.

You should cold boot (or power down) when changing between TOS and EMUTOS. Possible reset bug between OS changes.

FLASH UTIL sometimes crashes on verify - currently unknown why. Seems to be limited to my main test board currently.

 

Q & A

Q) I purchased a 40MHz unit, can I use 50MHz ?
A) Not likely with the supplied FPU & CPU. They were deemed rated for reliable 40MHz only.

Q) Can I swap the FPU & CPU to use 50MHz ?
A) Theoretically you could change them and use 50MHz. The exxos store now sells qualified CPUs and FPUs. However it is important to realise that finding parts which reliably work at those speeds is extremely difficult. Also there is a high risk of damaging the sockets. So I strongly advise that you do not attempt to change the FPU or CPU as such damages are not easily repairable!

Q) Does the CPU need cooling ?
A) I would strongly advise fitting a heatsink or even a small fan to keep the DFB1 cool overall and it will prolong CPU life etc.

Q) How does this compare to the CT60 ?
A) This is a incredibly difficult thing to answer. In a nutshell, the CT60 is faster, a lot more expensive and more problematical to install. The DFB1X is not as fast as the CT60, but its also a lot cheaper and simpler to install.

Q) Will the DFB1X work with "this or that" hardware addon or software ?
A) I'm afraid I don't know! I have a stock Falcon and that is it! Anything outside of this configuration, I'm afraid you are on your own.

Q) What is the red dot on the FPU ?
A) The red dot means I found the FPU cannot be overclocked reliably and was deemed a top speed of 40MHz.

Q) How do I update the firmware ?
A) Currently you must know how to do this already with suitable xlinix programming tools. I regret you will have to look on the Internet for guides on how to flash xlinix devices for windows / linux etc.

Q) Can I run the FPU on its own clock ?
A) While this is still technically possible, its has not been tested on the DFB1X and there is no guide currently on how to do this. Though in general there is really no point in doing this any more. 40MHz is generally the maximum speed of the FPU IC itself, and this is already a default speed on the booster. The jumper JC1 sets the CPU and FPU speed to 40MHz or 50MHz. So there is really no need for a separate oscillator. In general using a separate oscillator would just likely just cause more problems than it is worth. The FPU OSC option will likely be removed in future batches.

Q) Does the flash come preprogrammed ?
A) Bank zero is flashed with TOS404 by default. Generally you will already have this ROM on your motherboard anyway. Though the flash will run faster than the MB ROM when enabled. The second bank is free to program any other operating systems such as EMUTOS etc.

Q) Do I have to use MAPROM / NVDI etc ?
A) Yes! NVDI required because the blitter cannot access 32-bit addresses and therefore must be emulated within NVDI instead. MAPROM is needed to enable the 128MB alt-ram and do some general setup tasks for it. MAPROM also copies the operating system flash directly into the faster alt-ram for higher speeds than would otherwise be possible running from the flash chip itself.

Q) What is PRGFLAGS ?
A) PRGFLAGS (program flags) is needed to change program headers so that they use and load into alt-ram. By default any application will load into the slower ST-RAM. So we must use PRGFLAGS to tell the program to use the faster alt-ram memory.

Q) Why are some blitter graphics corrupted ?
A) You probably have not installed NVDI. It is needed to "disable" the blitter because it cannot access 32bit addresses when using alt-ram. Without NVDI the blitter will malfunction and you will get corrupted graphics. Incidentally, some blitter functions may also run fractionally slower than on a stock machine because of software emulation in NVDI and slower CPU functions. The blitting test in GB6 generally shows 83% speed for block blitting copy. Most blitter related functions are greatly speeded up with NVDI to a average of over 530% (tested with GB6).

Q) Is the DFB1 firmware compatible with the DFB1X ?
A) No! While the DFB1 firmware code base was used in the DFB1X, they are not compatible or interchangeable.

Q) What clock-patches does the DFB1 work with ?
A) Currently the DFB1X has only been tested with the exxos clock patch, V2,V3,V4 series. I cannot speculate on the outcome of any other clock patches or reliability of such.

Q) Do I need a heatsink or cooling ?
A) Short answer yes. There are compact heatsinks available in the store which should be used as a minimum. But are not fitted by default because there are potential clearance issues with the keyboard and metal shielding. Forced air via a small fan is ideal but there is no solutions to fitting one currently. 50MHz boards will run a lot hotter than the 40MHz types.

Q) What are the differences between the 40MHz and 50MHz boards ?
A) These are the differences between the FPU and CPU speeds offered in the store. As I am finding it difficult to find reliable 50MHz CPUs & FPUs, not many can be produced at that speed rating. I should also point out that 50MHz has not been tested for more than a couple of hours so cannot guarantee long-term reliability. Though these have been tested without a heatsink at all. So any long-term problems should be addressable by fitting a heatsink and adequate cooling.

Q) Can I overclock more than 50MHz ?
A) No. 50MHz I considered to already be the "cream on the cake". Finding CPUs which will generally run at 50MHz (or higher) is rather difficult because of the usual reprinting done on the CPUs. So there is no way to generally tell them apart from 25/33MHz parts. Technically a lot of them already overclocked running them at 40MHz.

Q) Can I switch flash banks via software ?
A) Unfortunately not. It would be a somewhat of a huge undertaking to adapt the hardware and software to do this. So rather than hold up development adding every little "nice thing", I decided to release things as operated as the original DFB1 project. I would suggest keeping TOS404 in the flash, and using EMUTOS.PRG if you need to switch OS.

Q) Can I disable the booster via software ?
A) Selecting 8MHz mode in SI.CPX will disable the 50MHz mode for compatibility with legacy software which runs to fast at 16MHz or above.

Q) Why was the FPU sold at 50MHz when its stamped as 40MHz?
A) 50MHz FPUs were never produced. The 50MHz rating comes from it being overclocked. It will be fully soak tested to prove it is reliable at 50MHz.

Q) Why are the barebones boards sold without sockets ? Can't you fit them ?
A) Once current stock is sold then likely all future boards will be sold without sockets fitted. This is because it has been incredibly difficult to ship items to China lately. Customs want detailed breakdown costs & relating paperwork of how much things cost, where thy were purchased from etc. Unfortunately some parts can be mixed in with other items purchased at the same time, even paperwork dating back several years. It would create a phenomenal amount of work to accurately breakdown just a few items on the off chance that customs will understand what they are reading and accept the package. The problem is, also as I end up paying shipping and tax to export sockets to China. Then when they are shipped back to me, I have to pay shipping and even more tax because I'm essentially buying back the sockets I sent them. Overall it has just become too time-consuming and costly to ship items back and forth to China for assembly.the sockets I already had purchased from China and they were custom-made, and I already paid shipping and tax on them once already. Paying tax on the same itmes 3 times is just madness. The sockets I cannot fit easily myself because of my RSI (and lack of time). The idea of the barebones boards is to make the DFB1X as cheap as possible to produce and make it more affordable to people to buy. If I start having to handle the boards and make changes, then the time & costs unfortunately will rapidly ramp up and it will not be such a good deal anymore.

Q) Do the barebones have firmware flashed?
A) Yes and no. While I have flashed firmware on some barebones boards, I cannot guarantee it is flashed and class them as not flashed. Flashed boards will have a exxos sticker on the bottom with the version flashed which is 104 at the time of typing.

More information may be found in the DFB WIKI.

 

BENCHMARKS @ 50MHz
BARE BONES PRODUCTION

These boards are sold "as is", un-tested and without CPU socket. It does not include the CPU or FPU. It does not have the firmware flashed. These boards are sold at a lower cost as they are not complete or tested.

 

JUMPERS TO SOLDER

The two jumpers need to be bridged as illustrated above. Pads 1&2 soldered for unbuffered CPU and FPU clock drive. Currently there has not been any requirement to use the buffered clocks and indeed that feature remains mostly untested. So the default is to solder them as illustrated above.

 

 

 

 

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