Writing ROMs for the Falcon

Various other hardware solutions.
BlankVector
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Re: Writing ROMs for the Falcon

Post by BlankVector »

Rustynutt wrote: Wed May 12, 2021 8:27 am I'm not familiar with all the adapters pictured (on eBay) that come with the XGecu TL866II Plus. Do any of those allow to be fitted over plcc's mounted to a board (clip over) so they can be read?
Normal usage of those adapters is :
- plug the adapter on the TL866II's ZIF socket
- plug the odd-shaped chip on the adapter
- read/write the chip using Xgpro software
- then extract the chip and use it on your own device

I have no idea if those adapters can be used differently than above (i.e. on your own board). And remember that the TL866II's ZIF socket only has 40 pins. It needs software tricks to drive adapters for chips with more pins.
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Badwolf
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Re: Writing ROMs for the Falcon

Post by Badwolf »

Rustynutt wrote: Wed May 12, 2021 8:27 am Notice you have the 44 pin plcc mounted to a cartridge port card.
I was under the impression the cartridge port could only access 256k.

Are you actually using an 4mb EmuTOS image/can be read by the cartridge port?
That's actually a ZIF TSSOP-48 socket for a 512kB flash chip. That particular one is used as a normal cartridge (128kB, by the way), with some jumpers to choose which quarter to use.

However, I have a second version that I have booted test ROMs from (512kB), but that requires pulling the onboard ROM, running two address wires from the expansion port out the side of the Falcon and also a jumper from the XROM2 chip enable line on the motherboard. But it was useful for rapid iteration of testing.
Next, can a HN27C1024HCC-85 PLCC-44,x16 EPROM be used in place of a HN27C4096HCC-85 PLCC-44?
Only if you've a 128kB ROM image (possible, but not readily useful). the 1024 means 1024 kilobits, the 4096 means 4096 kilobits.
I'm not familiar with all the adapters pictured (on eBay) that come with the XGecu TL866II Plus. Do any of those allow to be fitted over plcc's mounted to a board (clip over) so they can be read?
No. For many electrical and mechanical reasons before we get onto whether the software would support it.

The only PLCC thing on the mobo that's readable is the main system ROM anyway, which is socketed.

BW
DFB1 Open source 50MHz 030 and TT-RAM accelerator for the Falcon
DSTB1 Open source 16Mhz 68k and AltRAM accelerator for the ST
Smalliermouse ST-optimised USB mouse adapter based on SmallyMouse2
FrontBench The Frontier: Elite 2 intro as a benchmark
Rustynutt
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Re: Writing ROMs for the Falcon

Post by Rustynutt »

BlankVector wrote: Wed May 12, 2021 10:22 am
Rustynutt wrote: Wed May 12, 2021 8:27 am I'm not familiar with all the adapters pictured (on eBay) that come with the XGecu TL866II Plus. Do any of those allow to be fitted over plcc's mounted to a board (clip over) so they can be read?
Normal usage of those adapters is :
- plug the adapter on the TL866II's ZIF socket
- plug the odd-shaped chip on the adapter
- read/write the chip using Xgpro software
- then extract the chip and use it on your own device

I have no idea if those adapters can be used differently than above (i.e. on your own board). And remember that the TL866II's ZIF socket only has 40 pins. It needs software tricks to drive adapters for chips with more pins.
Thanks for that.
I'm familiar using Xilinx to flash the CT60, but not much else.

My interest, aside from Falcon ROM and bus GAL programming, is on another Falcon board.

Did some more research today, found information about Vantis and MACHXL software. What's in question is if the board was engineered with serial lines to the MACH CMOS programmable logic to program in circuit.
There is a header separate than the Falcon expansion connector on the board.
The "legacy" information is that it's a 32 bit interface to the card, but there is no documentation to support that, or otherwise.
To me, it wouldn't make sense to program the logic, then risk soldering them to the board. But who knows. That was 26 years ago.
So, have a lot of reading and meter time ahead.

Another part of the project relying on a cartridge port ROM to boot a different CPU than what the card is designed for.

Looking at Badwolf's setup, I can likely purchase the multi system diagnostic cart from Exxos and just replace the ROM. I'm definitely not past fly wiring circuit boards from Radio Shack yet :)

It's all in fun :)
Rustynutt
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Re: Writing ROMs for the Falcon

Post by Rustynutt »

Badwolf wrote: Wed May 12, 2021 3:34 pm
Rustynutt wrote: Wed May 12, 2021 8:27 am Notice you have the 44 pin plcc mounted to a cartridge port card.
I was under the impression the cartridge port could only access 256k.

Are you actually using an 4mb EmuTOS image/can be read by the cartridge port?
That's actually a ZIF TSSOP-48 socket for a 512kB flash chip. That particular one is used as a normal cartridge (128kB, by the way), with some jumpers to choose which quarter to use.

However, I have a second version that I have booted test ROMs from (512kB), but that requires pulling the onboard ROM, running two address wires from the expansion port out the side of the Falcon and also a jumper from the XROM2 chip enable line on the motherboard. But it was useful for rapid iteration of testing.
Next, can a HN27C1024HCC-85 PLCC-44,x16 EPROM be used in place of a HN27C4096HCC-85 PLCC-44?
Only if you've a 128kB ROM image (possible, but not readily useful). the 1024 means 1024 kilobits, the 4096 means 4096 kilobits.
I'm not familiar with all the adapters pictured (on eBay) that come with the XGecu TL866II Plus. Do any of those allow to be fitted over plcc's mounted to a board (clip over) so they can be read?
No. For many electrical and mechanical reasons before we get onto whether the software would support it.

The only PLCC thing on the mobo that's readable is the main system ROM anyway, which is socketed.

BW
Went into a little more detail why I'd asked above, and after a bit of research, kind of have a basic understanding.

But, when I ask you dumb questions, it causes me to read more, which is good :)

Right, 128K :) Kind of why never having interest in the cartridge until EmuTOS developed as far as it has.

Somewhere came across a 44pin PLCC adapter/extension socket. Issue is the ROM and ST RAM card location :)

How you created the circuit is much more convenient than swapping out the Falcon TOS ROM.

Reason asking about the 1024 ROM, can source them locally, not China.

Thanks!
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Badwolf
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Re: Writing ROMs for the Falcon

Post by Badwolf »

Rustynutt wrote: Fri May 14, 2021 7:18 am Looking at Badwolf's setup, I can likely purchase the multi system diagnostic cart from Exxos and just replace the ROM.
This might work, but could take some effort.
  • You need to make sure your ROM fits in 128kB. The EmuTOS cartridge release doesn't boot on the Falcon, you'll need to configure and build your own version that does;
  • Exxos' cart uses a 4906 rom and jumpers to select which area is exposed to the computer. A 1024 may not work, depending on what configuration the jumpers allows. You'll note there are 4 lots of 128kB in a 512kB ROM, but there are more than 4 options in the Exxos cartridge, meaning some, if not all, only expose 64kB to the computer;
  • You need to figure out which, if any of the jumper configurations will give you a full 128kB *somewhere* in the ROM;
  • You need to make sure your 128kB of ROM is located in this 512kB of ROM space such that it gets presented to the computer correctly;
  • The onboard ROM is needed for the first few commands before it hands over to the cartridge port, so this has to be working.
And, for clarity's sake: Exxos' diagnostic board will not let you expose 512kB of ROM to the computer without hardware modification of both the cartridge and the computer.

I would not recommend this approach until you're completely au fait with booting alternative ROMs in your Falcon. I'd very much recommend ordering the 4096 chips from china and replacing the on-board ROM instead.

BW
DFB1 Open source 50MHz 030 and TT-RAM accelerator for the Falcon
DSTB1 Open source 16Mhz 68k and AltRAM accelerator for the ST
Smalliermouse ST-optimised USB mouse adapter based on SmallyMouse2
FrontBench The Frontier: Elite 2 intro as a benchmark
Rustynutt
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Re: Writing ROMs for the Falcon

Post by Rustynutt »

I'd made some assumptions of the Exxos board layout, mainly only asking the question if the diagnostic image was original or a new test software was wrote. Since it was original, went with that info.
Inside a Falcon diagnostic cart, and replacement boards available via Wizztronics, figured it wouldn't be difficult discovering the Exxos switch position setting.

But honestly, just wanted to get away from building or adding a PLCC adapter, not concerned with the actual purpose and function of the Exxos board. That ROM will be pulled anyway.

As the ROMS in the Atari Falcon diagnostic, as a pair, are 8x64K-512k, and knowing the actual addressable space for the ROM port is 128k, assumed when a 128 (2x64, HI/LO assuming, something to learn here using a PLCC) image is wrote to a ROM, regardless of its size (ie, 1024 PLCC), it will appear to the cartridge port as 128k address space regardless of size because of the jumper settings.

Writing this, your point about his/possible 65k setting makes sense. Unless the Exxos board differs from the standard Atari board (other than bells and whistles), with the silkscreen info on the boards I have should be able to decipher the settings.
Unless I'm completely missing the point :)

Hehe, a 512K ROM port.
Would of outpaced Amiga sales with that capability :)

Cartridge ROM board
Cartridge ROM board
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frank.lukas
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Re: Writing ROMs for the Falcon

Post by frank.lukas »

To use two 27C512 Eproms with the original Atari cart pcb you have put /ROM3 and /ROM4 together with two BAT43 diodes ...
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Badwolf
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Re: Writing ROMs for the Falcon

Post by Badwolf »

Rustynutt wrote: Tue May 18, 2021 8:02 pm Unless the Exxos board differs from the standard Atari board
It's completely and utterly different. It uses a logic chip and a series of jumpers to expose 64k at a time from a 512k ROM chip.

BW
DFB1 Open source 50MHz 030 and TT-RAM accelerator for the Falcon
DSTB1 Open source 16Mhz 68k and AltRAM accelerator for the ST
Smalliermouse ST-optimised USB mouse adapter based on SmallyMouse2
FrontBench The Frontier: Elite 2 intro as a benchmark
Rustynutt
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Re: Writing ROMs for the Falcon

Post by Rustynutt »

frank.lukas wrote: Tue May 18, 2021 9:53 pm To use two 27C512 Eproms with the original Atari cart pcb you have put /ROM3 and /ROM4 together with two BAT43 diodes ...
As in the photo on the right?
Rustynutt
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Re: Writing ROMs for the Falcon

Post by Rustynutt »

Badwolf wrote: Tue May 18, 2021 10:42 pm
Rustynutt wrote: Tue May 18, 2021 8:02 pm Unless the Exxos board differs from the standard Atari board
It's completely and utterly different. It uses a logic chip and a series of jumpers to expose 64k at a time from a 512k ROM chip.

BW
That's fine, parts are there to rob off the board.

Maybe I misread the data for it, thought it contained Falcon diagnostic as well.
That, or is the Falcon diagnostic image only 64k?

If all else fails, have several 44 pin plcc OTP ROMs while waiting for a boat from China.

You know what S.R. Hadden said..
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