It appears the 'MAC' on the ICs is a bit misleading and was to denote it being part of a bundle sold for - but not specific to - the Macintosh.XK857J0 is not a version number; it is the Yamaha internal part catalog code for that specific mask ROM chip, commonly used during factory component production.
Because it is a factory-original mask ROM, it confirms your hardware is configured with the standard Version 1.x firmware base. This is excellent news for your Atari setup.
Yamaha used codes starting with "XK" or "XM" to track raw masked silicon inventory across their product lines. The XK857J0 chip contains the universal v1.20 series base code.
This is precisely the version Atari developers used when writing the Cubase Audio CBX hardware drivers.
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Things for sale at Cyber Legends 5....
- mrbombermillzy
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Re: Things for sale at Cyber Legends 5....
@JezC After a bit of a search around:
Re: Things for sale at Cyber Legends 5....
Thanks @mrbombermillzymrbombermillzy wrote: Fri Jul 17, 2026 12:24 pm @JezC After a bit of a search around:
It appears the 'MAC' on the ICs is a bit misleading and was to denote it being part of a bundle sold for - but not specific to - the Macintosh.XK857J0 is not a version number; it is the Yamaha internal part catalog code for that specific mask ROM chip, commonly used during factory component production.
Because it is a factory-original mask ROM, it confirms your hardware is configured with the standard Version 1.x firmware base. This is excellent news for your Atari setup.
Yamaha used codes starting with "XK" or "XM" to track raw masked silicon inventory across their product lines. The XK857J0 chip contains the universal v1.20 series base code.
This is precisely the version Atari developers used when writing the Cubase Audio CBX hardware drivers.
Sounds promising... will do some research on what s/w versions work with it, Cubase does IIRC but will check which versions and if they're available still.
Re: Things for sale at Cyber Legends 5....
So I think I shall have a Pistorm Amiga 500 and a C128 for sale at CL5.
May be a few more little bits, depending on how the week goes.
May be a few more little bits, depending on how the week goes.
If it ain't broke, test it to Destruction.
- rubber_jonnie
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Re: Things for sale at Cyber Legends 5....
I am planning on having the following STFMs to sell:
No 1 - TOS 1.04, 1MB RAM & Blitter - £120
No 2 - TOS 1.04, 1MB RAM & big button FDD - £100
No 3 - TOS 1.04, 1MB RAM & Blitter - £115 - The case was cut by a previous owner to facilitate a standard FDD drive as per the image below:
I also have two Mega STs for sale:
No 1 - TOS 1.04, 1MB RAM, Blitter and internal IDE HDD - £120
No 2 - TOS 1.04, 4MB RAM, Blitter and internal IDE HDD - £130
Both have a patched TOS for IDE to boot directly. Neither Mega has a keyboard, I always used them with Eiffel adapters as I only have one Mega keyboard, and I'm keeping that for my remaining Mega.
All the STFMs and Mega's have been powered on and boot fine and the FDDs have been tested by reading and writing to disks, formatting disks and running the diag cart disk tests.
I also have 2 DualTOS IDE cards for the ST:
They do require a DualTOS ROM (I just don't have any spare ROMs to burn and install) but they are fully functional and include a known good 68000 CPU. £25 each.
The other item in the picture is an Amiga 1200 68030 accelerator board. Also fully functional and IIRC has an 8MB simm onboard. £50
I will also have for sale a C64 C and Spectrum 48K:
Unfortunately neither has a PSU, but both are tested and working. The Spectrum has a Traco 7805 replacement fitted so runs nice and cool.
£45 each.
I will also be bringing some Pirto II and PiColeco ROM emulator boards for the respective consoles:
£15 each or £20 a pair.
Last but by no means least I have an SGI Octane I want to sell:
The specs are here:
£250 is I think a reasonable price for this machine based on current values on eBay.
Please note I have based all my prices on eBay sold item values and I think they are fair. I am happy to take cash on the day or Paypal on the day or in advance.
If anyone who is going on the day wants to reserve an item in advance please PM me and use the item descriptions above to reserve an item. If you wish to secure an item by paying in advance, let me know when you PM me and I will give you my PayPal details.
I will do it fairly on a first come first served basis based on the order I receive any messages.
Finally I will have a box of random bare PCBs to sell from various projects and may have some RGB2HDMI boards to sell on the day.
Thanks.
RJ
No 1 - TOS 1.04, 1MB RAM & Blitter - £120
No 2 - TOS 1.04, 1MB RAM & big button FDD - £100
No 3 - TOS 1.04, 1MB RAM & Blitter - £115 - The case was cut by a previous owner to facilitate a standard FDD drive as per the image below:
I also have two Mega STs for sale:
No 1 - TOS 1.04, 1MB RAM, Blitter and internal IDE HDD - £120
No 2 - TOS 1.04, 4MB RAM, Blitter and internal IDE HDD - £130
Both have a patched TOS for IDE to boot directly. Neither Mega has a keyboard, I always used them with Eiffel adapters as I only have one Mega keyboard, and I'm keeping that for my remaining Mega.
All the STFMs and Mega's have been powered on and boot fine and the FDDs have been tested by reading and writing to disks, formatting disks and running the diag cart disk tests.
I also have 2 DualTOS IDE cards for the ST:
They do require a DualTOS ROM (I just don't have any spare ROMs to burn and install) but they are fully functional and include a known good 68000 CPU. £25 each.
The other item in the picture is an Amiga 1200 68030 accelerator board. Also fully functional and IIRC has an 8MB simm onboard. £50
I will also have for sale a C64 C and Spectrum 48K:
Unfortunately neither has a PSU, but both are tested and working. The Spectrum has a Traco 7805 replacement fitted so runs nice and cool.
£45 each.
I will also be bringing some Pirto II and PiColeco ROM emulator boards for the respective consoles:
£15 each or £20 a pair.
Last but by no means least I have an SGI Octane I want to sell:
The specs are here:
£250 is I think a reasonable price for this machine based on current values on eBay.
Please note I have based all my prices on eBay sold item values and I think they are fair. I am happy to take cash on the day or Paypal on the day or in advance.
If anyone who is going on the day wants to reserve an item in advance please PM me and use the item descriptions above to reserve an item. If you wish to secure an item by paying in advance, let me know when you PM me and I will give you my PayPal details.
I will do it fairly on a first come first served basis based on the order I receive any messages.
Finally I will have a box of random bare PCBs to sell from various projects and may have some RGB2HDMI boards to sell on the day.
Thanks.
RJ
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...